CONTENTS

JOURNAL OF MACHINE ENGINEERING

o article: Model Based Compensation of Geometrical Deviations Due to Process Forces (DENKENA B., DAHLMANN D., PETERS R., WITT M.), pp. 5-16
o article: Intelligent Hybrid Material Slide Component for Machine Tools (MÖHRING H.-Ch., WIEDERKEHR P., BAUMANN J., KÖNIG A., SPIEKER Ch., MÜLLER M.), pp. 17-30
o article: Precise Modelling of Machine Tool Drives with Ball Screw Thermal Behaviour (WINIARSKI Z., KOWAL Z., JEDRZEJEWSKI J.,KWASNY W.), pp. 31-45
o article: Spindle Crash - Bearing Damages Detected by Vibration Tests (MAIER W., KIMMELMANN M.), pp. 46-56
o article: Simulation Based Optimization for Controller Parameterization of Machine Tool AXES - Advanced Application (HIPP K., SCHÖBERLEIN Ch., SCHLEGEL H., NEUGEBAUER R.), pp. 57-68
o article: Optimization of CNC Face Milling Process of AL-6061-T6 Aluminum Alloy (JAROSZ K., LÖSCHNER P., NIESLONY P., Grzegorz KROLCZYK G.), pp. 69-77
o article: Joining by Upset Bulging - Tooling Design and New Concepts for Online Process Control Using Servo Presses and Local Heating (SVIRIDOV A., GRUETZNER Ph., RUSCH M., BAMBACH M.), pp. 78-87
o article: Do we Need Capabilities in our Management System? (KANGILASKI T., SHEVTSEHNKO E.), pp. 88-100

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© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

MODEL BASED COMPENSATION OF GEOMETRICAL DEVIATIONS DUE TO PROCESS FORCES

Berend DENKENA¹, Dominik DAHLMANN¹, Rene PETERS¹, Matthias WITT ^1
1Leibniz Universität Hannover, Institute of Production Engineering and Machine Tools (IFW), Germany

Abstract

Machining accuracy can be considerably affected by deflections of machine tool components and the workpiece. This work presents a new approach for real-time deflection compensation, based on control integrated models. A real-time material removal rate (MRR) simulation determines the depth of cut which is used for process force calculation by Kienzle-Equations. Machine tool and workpiece deflections are then derived from a mechanical model using the calculated process forces. For this purpose, control based signals are used as model inputs. The total deviation is sent to the position controller as a setpoint offset. A dynamometer was applied to validate the simulated process forces. The presented approach was validated for cylindrical turning operations on chucked steel shafts. The experiments were carried out on a high-precision slant bed lathe. The results show, that geometrical errors could be reduced by more than 70% on average.

Author Keywords :

model based compensation, reduction of geometrical errors, real-time model

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

INTELLIGENT HYBRID MATERIAL SLIDE COMPONENT FOR MACHINE TOOLS

H.-Christian MÖHRING¹, Petra WIEDERKEHR², Jonas BAUMANN², Alexander KÖNIG¹, Christian SPIEKER³, Matthias MÜLLER^3
1Inst. of Manufacturing Technology and Quality Management (IFQ), Otto-von-Guericke Univ. Magdeburg, Germany
²Institute of Machining Technology (ISF), TU Dortmund University, Dortmund,Germany
³FOOKE GmbH, Borken, Germany

Abstract

In mid-scale and large five axis overhead gantry type milling machines, the vertical z-slide (ram) often constitutes one of the most sensitive and critical components regarding stiffness, structural vibrations and thermal influences. During machining, the z-slide is loaded by (quasi-) static process and drive forces, transient acceleration forces, periodic excitations by the tool engagement, as well as by thermal effects resulting from altering ambient conditions, heated chips, cooling lubricant and power losses in drives, guides and bearings. Deflections, thermal deformations and vibrations of the z-slide lead to geometric machining errors and inacceptable surface location errors at the workpieces. Furthermore, instable cutting conditions and regenerative chatter limit applicable material removal rates and, thus, productivity. In this work, a newly developed hybrid material structure for an exemplary z-slide, involving metal parts and mineral cast, is introduced. Structural optimization methods as well as process simulation techniques were applied in order to derive the final design solution. The integration of active cooling circuits for thermal stabilization is investigated and the use of fibre optical strain sensors is analysed with respect to a state monitoring of the machine tool component.

Author Keywords :

process stability simulation, thermal analysis, machine tool

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

PRECISE MODELLING OF MACHINE TOOL DRIVES WITH BALL SCREW THERMAL BEHAVIOUR

Zdzislaw WINIARSKI¹, Zbigniew KOWAL¹, Jerzy JEDRZEJEWSKI¹, Wojciech KWASNY^1
1Wroclaw University of Technology, Department of Machine Tools and Mechanical Technologies, Wroclaw, Poland

Abstract

This paper briefly describes the current requirements which machine tool ball screws must meet and indicates the need for the modelling and numerical simulation of the latter. The structure of a holistic ball screw model and ways of modelling the properties of the ball screw in a turning centre, including the moving heat sources on the guides and in the screw-nut joint, are presented. The results of computing the heating up and displacements of a preloaded screw and the screw without preload are reported. The modelled changes in motion resistance and in displacements are shown to be in agreement with the results of measuring the current drawn by the drive's motor. It is also shown that the models represent well the real physical phenomena occurring in the ball screw during the execution of repeatable work cycles by the drive.

Author Keywords :

machine tool, feed drive, ball screw, moving heat sources, numerical simulation

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

SPINDLE CRASH - BEARING DAMAGES DETECTED BY VIBRATION TESTS

Walther MAIER¹, Martin KIMMELMANN^1
1University of Stuttgart, Institute for Machine Tools (IfW), Stuttgart, Germany

Abstract

This paper presents experiments regarding the collision of a main spindle with a fixed machine body, i.e. a machine crash. Using experimental tests, it is shown how a machine crash affects the main spindle and its components. After the crash test under laboratory conditions, damages in the form of constrictions and transverse grooves in the bearing rings of the hybrid bearings are detected with roundness tests. Focused on the effects of a crash on high-speed bearings, vibration analyses of the motor spindle are carried out before and after the spindle crash. This paper presents how experimental order tracking analysis and roundness tests can be used to draw conclusions about the spindles' state, especially about bearing damages caused by the collision.

Author Keywords :

motor spindle, bearing, vibration analysis, collision test - spindle crash

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

SIMULATION BASED OPTIMIZATION FOR CONTROLLER PARAMETERIZATION OF MACHINE TOOL AXES - ADVANCED APPLICATION

Kevin HIPP¹, Chris SCHÖBERLEIN¹,Holger SCHLEGEL¹, Reimund NEUGEBAUER^1
1Chemnitz University of Technology, Faculty of Mechanical Engineering, Professorship for Machine Tools and Forming Technology, Chemnitz, Germany

Abstract

The quality of the controller parameterization of a drive system has direct influence on the obtained performance. Nevertheless, the commissioning is mainly done today by the application of basic tuning rules or not comprehensible automatisms. This often leads to not optimal performance. An alternative approach is to parameterize the typical controller cascade, which is widely used in standard industrial controllers, in one step by using the so-called "simulation-based optimization" (SBO). Significant advantages are the opportunity of defining specific restrictions concerning the desired controller parameterization and the possibility for directly processing non-linear systems without approximations. Furthermore, friction, additional filters in the cascade or controller structure extensions like the Advanced Position Control (APC) can be considered. Therefore, in the present paper, the application and the results of the SBO for different drive systems will be presented. After an introduction, the paper describes the basic principles of the simulation based optimization including the application for controller parameterization. Subsequently, the results for indirect velocity control of a test rig are discussed. After that, the findings for the commissioning of a direct position controller of an industrial servo press are presented. The paper closes with a summary and an outlook.

Author Keywords :

simulation-based optimization, commissioning, controller parameterisation, servo press

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

OPTIMIZATION OF CNC FACE MILLING PROCESS OF AL-6061-T6 ALUMINUM ALLOY

Krzysztof JAROSZ¹, Piotr LÖSCHNER¹,Piotr NIESLONY¹, Grzegorz KROLCZYK^1
1Opole University of Technology, Faculty of Mechanical Engineering, Department of Manufacturing Engineering and Automation, Opole, Poland

Abstract

In modern machining industry, the use of computer software is an integral element in the design of technological processes. This work aims to present possibilities for optimization of milling operations with the use of commercial software designed especially for that use. A face milling operation of an aluminium flange was chosen for this study.Several different optimization strategies were described and their results shown, analysed and discussed. The effect of variable radial depth of cut on cutting force values in milling processes was reflected upon. Additionally, further research involving comparison of experiment results with simulation was proposed. It was proven that correct optimization strategy can reduce machining time for the analysed face milling operation about 37% without exceeding imposed process parameter constraints.

Author Keywords :

aluminum alloys, CNC, face milling, optimization

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

JOINING BY UPSET BULGING - TOOLING DESIGN AND NEW CONCEPTS FOR ONLINE PROCESS CONTROL USING SERVO PRESSES AND LOCAL HEATING

Alexander SVIRIDOV¹, Philip GRUETZNER²,Michael RUSCH¹,Markus BAMBACH ^1
1Brandenburg University of Technology Cottbus-Senftenberg, Chair of Mechanical Design and Manufacturing, Germany
²HTW Berlin, University of Applied Sciences, Berlin, Germ

Abstract

Conventional fusion-welding techniques pose limitations in modern multi-material assemblies due to the heat input. The negative influence of the heat-affected zone on the material properties must be avoided particularly in high-strength steels. During mechanical joining processes, which may also be used for joining of different materials e.g. steel and aluminium, high-performance joints can be produced without degradation of the material properties. Joining by upset bulging is an innovative joining method based on plastic buckling of tubes under axial compression. In previous investigations of joining by upset bulging the process parameters were determined and joints of tubes with sheet metal were tested under static and dynamic l oads. The results of these studies have shown that the process of upset bulging has a large potential for the production of joints of tubes with sheets and plates. The present paper focuses on the tooling concepts for an efficient use of the technology and describes methods to control the forming and joining process. Two aspects are covered: (i) the application of servo-presses for joining by upset bulging and their possibilities for on-line process control, (ii) a moderate, process-integrated local heating of the forming area to avoid the formation of cracks and to further increase the strength of the joints.

Author Keywords :

tube forming, mechanical joining, upset bulging, local heating, servo press

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

DO WE NEED CAPABILITIES IN OUR MANAGEMENT SYSTEM?

Taivo KANGILASKI¹, Eduard SHEVTSHENKO^1
1Tallinn University of Technology, Department of Mechanical and Industrial Engineering, Tallinn, Estonia

Abstract

To be agile and adaptive, the production systems need to be able to meet the changing market requirements regarding product characteristics, quantities, on-time delivery, and cost. Most of the production companies in Europe have or have pretended to be certified for management systems ISO 9001:2015 (Quality Management), ISO 14001:2015 (Environmental Management) and OHSAS 18001 (occupational health and safety management system specification) as well. On top of that, asset-intensive companies are implementing ISO 55000:2014 (Standards for Asset Management), that enables them to assure that they use corporation assets correctly. All these management systems are complementary and are the base for business process management. When a company has documented processes, it becomes the valuable asset for analyses and optimisation.The current article arguments that the business process management, including risks, qualifications,objectives, opportunities, etc. are not enough for smooth enterprise management without capability planning and management. Authors suggest that in addition to ISO demand companies must have documented and managed capabilities.

Author Keywords :

enterprise architecture, process documentation framework, capabilities

CONTENTS

JOURNAL OF MACHINE ENGINEERING

o article: Intelligent Production Systems in the Era of INDUSTRIE 4.0 - Changing Mindsets and Business Models (UHLMANN E., HOHWIELER E., GEISERT C.), pp. 5-24
o article: A Critical Review of Characteristic Techniques for Improving the Cutting Performance of Coated Tool (BOUZAKIS K-D., SKORDARIS G., BOUZAKIS E., KOTSANIS T., CHARALAMPOUS P.), pp. 25-44
o article: Smart Wireless Sensor Network and Configuration of Algorithms for Condition Monitoring Applications (UHLMANN E., LAGHMOUCHI A., GEISERT C.), pp. 45-55
o article: Influence of Tool Nose Radius on the Cutting Performance and Surface Finish During Hard Turning with CBN Cutting Tools (GRZESIK W., ZAK K., CHUDY R.), pp. 56-64
o article: Intelligent Pattern Recognition of SLM Machine Energy Data (UHLMANN E., PASTL PONTES R., LAGHMOUCHI A., HOHWIELER E., FEITSCHER R.), pp.65-76
o article: Flexible Coupling of Drive and Guide Elements for Parallel-Driven Feed Axes to Increase Dynamics and Accuracy of Motion (PEUKERT Ch., MERX M., MÜLLER J., IHLENFELDT S.), pp. 77-89
o article: Limitations of Notation System in Centred Part Alignment Accuracy Imposed by ISO Standard and Proposal for an Improved Methodology (YAN Y., BOHN M.), pp.90-101
o article: Numerical Analysis of the Steam Flow Past the Turbine Blade Stage (ROGOWSKI K., PAWLICKI J.), pp. 102-110

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© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

INTELLIGENT PRODUCTION SYSTEMS IN THE ERA OF INDUSTRIE 4.0 - CHANGING MINDSETS AND BUSINESS

Eckart UHLMANN^1,2, Eckhard HOHWIELER¹, Claudio GEISERT^1
1Fraunhofer Institute for Production Systems and Design Technology (IPK), Germany
²Technische Universität Berlin - Institute for Machine Tools and Factory Management (IWF), Germany

Abstract

Industrie 4.0 has been becoming one of the most challenging topic areas in industrial production engineering within the last decade. The increasing and comprehensive digitization of industrial production processes allows the introduction of innovative data-driven business models using cyber-physical systems (CPS) and Internet of Things (IoT). Efficient and flexible manufacturing of goods assumes that all involved production systems are capable of fulfilling all necessary machining operations in the desired quality. To ensure this, production systems must be able to communicate and interact with machines and humans in a distributed environment, monitor the wear condition of functionally relevant components, and to self-adapt their behaviour to a given situation. This article gives an overview about the historical velopment of intelligent production systems in the context of value-adding business models. The focus is on condition monitoring and predictive maintenance in an availability oriented business model. Technical as well as organizational prerequisites for an implementation in the production industry are critically analysed and discussed on the basis of best practice examples. The paper concludes with a summary and an outlook on future research topics that should be addressed.

Author Keywords :

industrie 4.0, internet-of-things,cyber-physical systems, industrial product-service systems,condition monitoring, predictive maintenance

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

A CRITICAL REVIEW OF CHARACTERISTIC TECHNIQUES FOR IMPROVING THE CUTTING PERFORMANCE OF COATED TOOLS

Konstantinos-Dionysios BOUZAKIS¹, Georgios SKORDARIS1,2, Tilemachos KOTSANIS¹, Paschalis CHARALAMPOUS^1
1Laboratory for Machine Tools and Manufacturing Engineering, Mechanical Engineering Department, Aristotle University of Thessaloniki, Greece
²German University of Technology in Oman (GUtech), Department of Engineering, Sultanate of Oman

Abstract

The cutting performance of PVD coated tools can be significantly improved by applying optimized PVD processes, film architectures, as well as appropriate pre- and post- treatments of the substrates and coated surfaces respectively. Substrate pre-treatments aim, among others, at improving the coating adhesion. In this way, lower coating loads develop during cutting leading to a decelerated wear evolution. Furthermore, the effect of various PVD process parameters and film architectures such as of adhesive interlayers, Ar+ ions bombardment, thickness distribution and multi-layer structure on the coated tool life is demonstrated. Finally, the potential to increase the wear resistance of coated tools via micro-blasting and to render sharp cutting edges mainly of small diameter tools more stable by rounding them via grinding is presented. Micro-blasting parameters such as of grain material, pressure, dry or wet etc., affect significantly the superficial coatings' hardness and brittleness and in this way their wear behaviour. To check the effectiveness of all these methods, innovative coating's characterization procedures providing information concerning the film and substrate properties as well as adhesion are applied, thus reducing the required experimentation time.

Author Keywords :

pre and post-treatments, PVD-coatings, wear

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

SMART WIRELESS SENSOR NETWORK AND CONFIGURATION OF ALGORITHMS FOR CONDITION MONITORING APPLICATIONS

Eckart UHLMANN^1,2, Abdelhakim LAGHMOUCHI¹, Claudio GEISERT¹, Eckhard HOHWIELER^1
1Fraunhofer Institute for Production Systems and Design Technology (IPK), Germany
²Technische Universität Berlin - Institute for Machine Tools and Factory Management (IWF), Germany

Abstract

Due to high demand on availability of production systems, condition monitoring is increasingly important. In recent years, the technical development have improved for realization of condition monitoring applications as a result of technological progress in fields such as sensor technology, computer performance and communication technology. Especially, the approaches of Industrie 4.0 and the use of the Internet of Things (IoT) technologies offer high potential to implement condition monitoring solutions. The connection of several sensor data of components to the cloud allows the identification of anomalies or defect pattern,this information can be used for predictive maintenance and new data-driven business models in production industry. This paper illustrates a concept of a smart wireless sensor network for condition monitoring application based on simple electroniccomponents such as the single-board computer Raspberry Pi 2 modules and MEMS (Micro-Electro-Mechanical Systems) vibration sensors and communication standards MQTT (Message Queue Telemetry Transport). The communication architecture used for decentralized data analysis using machine learning algorithms and connection to the cloud is explained. Furthermore, a procedure for rapid configuration of condition monitoring algorithms to classify the current condition of the component is demonstrated.

Author Keywords :

condition monitoring, data analysis, sensor network, algorithm, MEMS sensor, cloud

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

INFLUENCE OF TOOL NOSE RADIUS ON THE CUTTING PERFORMANCE AND SURFACE FINISH DURING HARD TURNING WITH CBN CUTTING TOOLS

Wit GRZESIK¹, Krzysztof ZAK¹, Roman CHUDY^1
1Opole University of Technology, Faculty of Mechanical Engineering, Opole, Poland

Abstract

In this paper the basic cutting characteristics such as cutting forces, cutting power and its distribution, specific cutting energies and friction were determined as functions of variable tool corner radius ranging from 400 to 1200 ?m and the cutting speed ranging from 150 m/min to 270 m/min for a hardened 41Cr4 alloy steel of 55?1 HRC hardness in finish turning steel using chamfered CBN tools. Moreover, selected roughness profiles produced for different tool corner radius were compared and appropriate surface roughness parameters were determined. The measured values of Ra and Rz roughness parameters were compared with theoretical values and springback effect was taken into account.

Author Keywords :

hardened steel, surface roughness, cutting force, specific energy, corner radius

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

INTELLIGENT PATTERN RECOGNITION OF SLM MACHINE ENERGY DATA

Eckart UHLMANN^1,2, Rodrigo PASTL PONTES¹, Abdelhakim LAGHMOUCHI¹, Eckhard HOHWIELER¹, Roberto FEITSCHER^1
1Fraunhofer Institute for Production Systems and Design Technology (IPK), Germany
²Technische Universität Berlin - Institute for Machine Tools and Factory Management (IWF), Germany

Abstract

Selective Laser Melting (SLM) is an additive manufacturing process, in which the research has been increasing over the past few years to meet customer-specific requirements. Different parameters from the process and the machine components have been monitored in order to obtain vital information such as productivity of the machine and quality of the manufactured workpiece. The monitoring of parameters related to energy is also realized, but the utilisation of such data is usually performed for determining basic information, for instance, from energy consumption. By applying machine learning algorithms on these data, it is possible to identify not only the steps of the manufacturing process, but also its behaviour patterns. Along with these algorithms, evidences regarding the conditions of components and anomalies can be detected in the acquired data. The results can be used to point out the process errors and component faults and can be adopted to analyse the energy efficiency of the SLM process by comparing energy consumption of one single layer during the manufacturing of different components. Moreover, the state of the manufacturing process and the machine can be determined automatically and applied to predict failures in order to launch appropriate counter measures.

Author Keywords :

pattern recognition, data analysis, additive manufacturing,energy data

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

FLEXIBLE COUPLING OF DRIVE AND GUIDE ELEMENTS FOR PARALLEL-DRIVEN FEED AXES TO INCREASE DYNAMICS AND ACCURACY OF MOTION

Christoph PEUKERT¹, Marcel MERX¹, Jens MÜLLER¹, Steffen IHLENFELDT^1
1Technische Universität Dresden, Faculty of Mechanical Science and Engineering, Institute of Machine Tools and Control Engineering, Dresden, Germany

Abstract

Productivity enhancement is achievable by increasing the dynamics of machines. This can be accomplished by decreasing the moving mass or by increasing the driving forces. One possibility for increasing the drive forces lies in the use of multiple parallel-acting actuators. Because of the mechanical coupling between the drives, undesirable interference of the actuators occurs. This limits the control bandwidth of the feed axis. Feed axes of machine tools are mostly equipped with linear guides fitted with rolling elements. Since they dispose of just one degree of freedom, small errors in their alignment or thermally induced errors cause constraining loads. In this paper compliant mechanisms are used to mechanically decouple the slide from the guide and drive elements. The application of flexible joints in gantryaxes with linear motors and ball screws is investigated. The dynamic behaviour of the feed axis components are modelled using the Finite Element Method. By applying the modal reduction technique, the dynamic behaviour is included in an elastic multibody simulation. With the mechanical decoupling of the drive and guide elements it is possible to increase the control bandwidth of the system. Deviations in motion may also be corrected with parallel-driven feed axis by applying compliant mechanisms.

Author Keywords :

compliant mechanism, parallel-driven feed axis, machine tool, control bandwidth

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

LIMITATIONS OF NOTATION SYSTEM IN CENTRED PART ALIGNMENT ACCURACY IMPOSED BY ISO STANDARD AND PROPOSAL FOR AN IMPROVED METHODOLOGY

Yiqing YAN¹, Martin BOHN^1
1Daimler AG, Research & Development Body in White, Dimensioning & Tolerancing, Germany

Abstract

According to the ISO Geometrical Product Specifications (GPS), centred part alignment with one centred point can be described clearly using technical drawings. There are two main limitations of this standard; Firstly: the uncertainty over use of notations in technical drawings when more than one centred point is applied, and secondly, the use of fixed datum targets to centred points which causes an unstable alignment process. This article suggests a new approach for a functional, explicitly defined notation system of datums and datum systems based on the research of orientation constraints between datums. This new approach simplifies the technical drawing, thereby eliminating notation uncertainties. An improved methodology for a stable alignment process was developed based on physical analysis of the centred part alignment which implements movable datum targets.

Author Keywords :

geometrical product specifications, part alignment, datum

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

NUMERICAL ANALYSIS OF THE STEAM FLOW PAST THE TURBINE BLADE STAGE

Krzysztof ROGOWSKI¹, Jakub PAWLICKI^1
1Warsaw University of Technology, Faculty of Power and Aeronautical Engineering, Warsaw, Poland

Abstract

The steam flow past a last stage (the eleventh stage) of the high pressure part of the TK120 steam turbine was investigated using computational fluid dynamics (CFD). The simulations are performed using the unsteady compressible Navier-Stokes equations. Viscous steam flow has been analyzed using the Spalart-Allmaras turbulence model. The paper presents distributions of instantaneous flow parameters around turbine blades as well as instantaneous aerodynamic blade loads. Flow parameters such as: velocity and static pressure are presented as contour maps whereas aerodynamic loads, axial and circumferential, are given as functions of time. Theoretical power of the examined turbine stage is 4.11 MW. Based on the numerical investigations the power of the analyzed stage is evaluated to be 3.5 MW. All presented in this paper results have been performed using the ANSYS Fluent solver.

Author Keywords :

computational fluid dynamics, steam turbine, turbulence model

CONTENTS

JOURNAL OF MACHINE ENGINEERING

o article: Design of Holonic Manufacturing Systems (BRUSSEL H V., P VALCKENAERS P., ), pp. 5-23
o article: Trajectory Planning for Kinematically Redundant Robots Using Jacobi Matrix - an Industrial Implementation (WALTHER M., SEWOHL A., SCHLEGEL H., NEUGEBAUER R.), pp. 24-35
o article: Optimized Grid Structures for the Characteristic Diagram Based Estimation of Thermo-Elastic Tool Center Point Displacements in Machine Tools (PUTZ M., IHLENFELDT S, NAUMANN Ch., GLÄNZEL J.), pp. 36-50
o article: Interests of 5 axis Toolpaths Generation for Wire ARC Additive Manufacturing of Aluminum Alloys (HASCOET J.Y., QUERARD V., RAUCH M.), pp. 51-65
o article: Properties of the Subsurface Layer after Rolling Burnishing of an Initially Milled Aluminium Alloy (KALISZ J., GRZESIK W., ZAK K., CZECHOWSKI K.), pp.66-74
o article: Modelling of Material Behaviour for Inconel 718 Superalloy Using Experimental Data (NIESLONY P., GRZESIK W., LASKOWSKI P.), pp. 75-84
o article: Abrasive Waterjet Technologies Used in Combination with Conventional Metal Cutting (WANNER B., ARCHENTI A., NICOLESCU M.), pp. 85-96
o article: Micro-EDM Process Modeling and Machining Approaches for Minimum Tool Electrode Wear for Fabrication of Biocompatible Micro-Components (PUTHUMANA G.), pp. 97-111
o article: Economic Analysis of Small Wind Turbines (KARCZEWSKI M., BASZCZYNSKI P., WIKLAK P., SOBCZAK K., JOZWIK K.), pp. 112-123

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© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

DESIGN OF HOLONIC MANUFACTURING SYSTEMS

Hendrik Van BRUSSEL¹, Paul VALCKENAERS^2
1Faculty of Engineering Science, KU Leuven, Belgium
²Faculty of Engineering Technology, KU Leuven, Belgium

Abstract

The introduction of CIM (Computer Integrated Manufacturing) systems in the 1980s, aiming at integrating automatic workstations into fully automated factories, was not successful. The root causesof this failure were that the subsystems to be integrated were not suitably designed for easy integration into a larger system. This situation stimulated the authors to embark on a research programme on 'design for the unexpected'. It defined how subsystems have to be designed so that integration into larger systems becomes easier and how such an integrated system can be controlled so that it can cope with change and disturbances. In the paper, the design principles and salient features of holonic manufacturing systems (HMS) are outlined. The PROSA reference architecture, defining the basic structure of any HMS, is described. It is further explained how coordination and control of the HMS is achieved by a holonic manufacturing execution system (HMES), based on the combination of the PROSA reference architecture and a biologically inspired Delegate Multiagent System (DMAS). Finally, the power and universality of the PROSA/DMAS system is demonstrated by some case studies from manufacturing , robotics and open air engineering.

Author Keywords :

holonic manuafacturing systems, integration, control, reference architecture, virtual execution

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

A TRAJECTORY PLANNING FOR KINEMATICALLY REDUNDANT ROBOTS USING JACOBI MATRIX – AN INDUSTRIAL IMPLEMENTATION

Michael WALTHER¹, Andre SEWOHL¹, Holger SCHLEGEL¹, Reimund NEUGEBAUER^1
1Chemnitz University of Technology, Faculty of Mechanical Engineering, Professorship for Machine Tools and Forming Technology, Germany

Abstract

The widespread use of robots in industry contributes significantly to high productivity. Serial 6-axis robots are used in large quantities, e.g. for assembly or welding. A current emerging trend is the use of robots for classic tasks of a machine tool like finishing of milled workpieces. For such applications, standard robots are usually extended by additional axes like linear axes or rotary tilting tables. Therefore, the overall system becomes kinematically redundant. To be able to calculate the axis quantities via inverse kinematics for a given path, additional degrees of freedom must be bound. In order to automatically and optimally consider the additional axis motion a method, using the pseudoinverse of the Jacobian matrix, is discussed. Due to the dependence of the Jacobi matrix on the robot's current joint position, numerical inaccuracies, which in turn reflect a path error, are inherent to this method. By feedback control of the path error, in the form of a classic control loop, the error can be reduced so that a practical implementation on industrial robot controller is possible. In the article possibilities for parameterisation of the algorithm as well as proof of stability of the closed loop are presented. The results obtained are verified by a concrete application.

Author Keywords :

redundant robots, trajectory planning,jacobian matrix, pseudoinverse

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

OPTIMIZED GRID STRUCTURES FOR THE CHARACTERISTIC DIAGRAM BASED ESTIMATION OF THERMO-ELASTIC TOOL CENTER POINT DISPLACEMENTS IN MACHINE TOOLS

Matthias PUTZ¹, Steffen IHLENFELDT², Christian NAUMANN¹, Janine GLÄNZEL^1
1Fraunhofer Institute for Machine Tools and Forming Technology IWU, Chemnitz, Germany
²Technische Universität Berlin - Institute for Machine Tools and Factory Management (IWF), Germany

Abstract

It is a well-known problem of milling machines, that waste heat from motors, friction effects on guides and also the milling process itself greatly affect the positioning accuracy and thus the production quality. An economic and energy-efficient method of correcting this thermo-elastic positioning error is to gather sensor data from the machine tool and the process and to use that information to predict and correct the resulting tool center point displacement using high dimensional characteristic diagrams. The size of these characteristic diagrams depends on the number of input variables (sensors) and the fineness of the discretization of the grid. While the number of sensors can usually not be reduced without affecting the quality of the prediction, it is often possible to minimize the size of characteristic diagrams through the use of adaptive grid refinement. This ensures that the finest grid sections correspond with the load cases that have the largest local gradients. Through such adaptive refinement, it is possible to reduce storage capacity and computation time without significant loss of precision. The aim of this article is to examine, test and compare different methods of adaptive grid refinement. For this, simulation data from a machine tool is used.

Author Keywords :

characteristic diagram, adaptive structured grids, thermo-elastic deformation, grid optimization, thermal error estimation

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

INTERESTS OF 5 AXIS TOOLPATHS GENERATION FOR WIRE ARC ADDITIVE MANUFACTURING OF ALUMINUM ALLOYS

Jean-Yves HASCOËT¹, Vincent QUERARD¹, Matthieu RAUCH^1
1Institut de Recherche en Génie Civil et Mécanique (GeM), Ecole Centrale de Nantes, France

Abstract

Additive Manufacturing (AM) for metal part can be divided into two different types: The powder technology and the wire technology. Usually, powder is adapted for fine components and small parts whereas wire is used for structural components and large scale part. One of the main benefits of AM is to simplify assemblies by reducing the number of components and to provide a large freedom of design. A standard AM system consists of a combination of three blocks: a motion system, a heat source and a feedstock. For Wire Arc Additive Manufacturing (WAAM), the heat source is a welding generator and the feedstock is a wire. The motion system generally used is a 6 axis robot or a CNC machine. This paper aims to propose a methodology to generate 5 axis toolpaths for WAAM and highlight the main parameters which selection is a key issue to resolve. The goal is to compare 3 axis and 5 axis toolpaths on part accuracy, depending the clearance angle of the part.

Author Keywords :

additive manufacturing, 5 axis manufacturing, WAAM

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

PROPERTIES OF THE SUBSURFACE LAYER AFTER ROLLING BURNISHING OF AN INITIALLY MILLED ALUMINIUM ALLOY

Janusz KALISZ¹, Wit GRZESIK², Krzysztof ZAK², Kazimierz CZECHOWSKI^1
1Institute of Advanced Manufacturing Technology, Krakow, Poland
²Opole University of Technology, Faculty of Mechanical Engineering, Poland

Abstract

This paper characterizes mechanical properties of the technological subsurface layer produced by medium milling of EM AW-AlCu4MgSi(A) aluminium alloy in hardened state T451 using a ball-end cutter and subsequent roller burnishing using a nitride ceramic ball. It was revealed that ball burnishing operations performed on curvilinear milled surfaces allow obtaining the subsurface layer with a minimum strain-hardening effect and induced compressive residual stresses without visible microstructural changes. As a result, such functional properties of the subsurface layer as fatigue strength, bearing properties and contact strength along with a very smooth machined surface of the Sa roughness of about 0.02 ?m can be ensured.

Author Keywords :

aluminium, milling, burnishing, hybrid machining, subsurface layer

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

MODELLING OF MATERIAL BEHAVIOUR FOR INCONEL 718 SUPERALLOY USING EXPERIMENTAL DATA

Piotr NIESLONY¹, Wit GRZESIK¹, Piotr LASKOWSKI^2
1Opole University of Technology, Faculty of Mechanical Engineering, Department of Manufacturing Engineering and Automation, Poland
²Pratt & Whitney, Rzeszow, Poland

Abstract

In this paper parameters of the Johnson-Cook (J-C) constitutive material model were predicted more accurately based on the static and dynamic material tests and mathematical modelling of relevant response surfaces using specially developed Matlab scripts. Experimental tests were performed under strain rates of 10-3 and 101 1/s and the temperature ranging from the ambient up to 700?C. As a result, a set of mathematical models which fit the experimental data was determined. The experimentally-derived constitutive models were implemented into FEM-based simulations of real machining processes of Inconel 718.

Author Keywords :

modelling, machining, constitutive model

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

HYBRID MACHINING: ABRASIVE WATERJET TECHNOLOGIES USED IN COMBINATION WITH CONVENTIONAL METAL CUTTING

Bertil WANNER¹, Andreas ARCHENTI¹, Cornel Mihai NICOLESCU^1
1KTH Royal Institute of Technology, Stockholm, Sweden

Abstract

Abrasive Waterjet technology is one of the fastest growing metal cutting technologies. Even so, very little published material is available on hybrid processing where abrasive waterjet cutting is one of two or more metal cutting methods. There is also limited published material on thin-walled components cut with abrasive waterjet technology. This paper makes a comparison of conventional metal cutting methods to the more unconventional abrasive waterjet technique. It will serve as a stepping stone in building knowledge aiding in hybrid machining development. It will show the possibilities and limitations during milling of thin-walled Aluminum components and then compare this to the capabilities of abrasive waterjet cutting the same components. Differences in material removal and revert control as well as in vibrations and force requirements will be reviewed. In addition, the environmental issues will be discussed and it will be determined which of the methods is more sustainable. The paper also includes a large section on process methodology.

Author Keywords :

hybrid processing, abrasive waterjet, thin-wall milling, sustainability

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

MICRO-EDM PROCESS MODELING AND MACHINING APPROACHES FOR MINIMUM TOOL ELECTRODE WEAR FOR FABRICATION OF BIOCOMPATIBLE MICRO-COMPONENTS

Govindan PUTHUMANA^1
1Department of Mechanical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark

Abstract

Micro-electrical discharge machining (micro-EDM) is a potential non-contact method for fabrication of biocompatible micro devices. This paper presents an attempt to model the tool electrode wear in micro-EDM process using multiple linear regression analysis (MLRA) and artificial neural networks (ANN).The governing micro-EDM factors chosen for this investigation were: voltage (V), current (I), pulse on time (Ton) and pulse frequency (f). The proposed predictive models generate a functional correlation between the too The optimum architecture of the ANN was obtained with 7 hidden layers at an R-sq value of 0.98. The predicted values of TWR using ANN matched well with the practically measured and calculated values of TWR. Based on the proposed soft computing-based approach towards biocompatible micro device fabrication, a condition for the minimum tool electrode wear rate (TWR) was achieved.

Author Keywords :

biocompatibility, micro devices, electrical discharge machining, modeling, multiple linear regression, artificial neural networks

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

ECONOMIC ANALYSIS OF SMALL WIND TURBINES

Maciej KARCZEWSKI¹, Piotr BASZCZYNSKI¹, Piotr WIKLAK¹, Krzysztof SOBCZAK¹, Krzysztof JOZWIK^1
1Institute of Turbomachinery, Lodz University of Technology, Lodz, Poland

Abstract

The paper analyses the market of small wind turbines from the economic point of view. The analysis judges an investment in a small wind turbine power plant on the basis of different economic indicators, such as Simple Payback (SPB), Net Profit Value (NPV) and Internal Rate of Return (IRR). Turbines from European and Polish markets were picked as the rated power of up to 10 kW was established as the main criterion for the selection. Calculations of the tip-speed ratio and power coefficient are performed based on the wind resource reference data. On the basis of these considerations, economic effectiveness study is performed via an estimated profit income from the turbine purchase. The model is further used to determine the cost of a small wind turbine power plant that could compete on the current prosumer market dominated by photovoltaic and solar panels.

Author Keywords :

wind turbine, economic efficiency,investment, Renewable Energy Source

CONTENTS

SPONSORING
Issue No.4, 2017 is sponsored by the Ministry of Science
and Higher Education of Poland - funding for DOI

JOURNAL OF MACHINE ENGINEERING

o article: Layout Design for Flexible Machining Systems in FCIPS and Convertibility to CPS Module in Smart Factory (ITO Y.), pp. 5-28
o article: Modular Intelligent Fixture System for Flexible Clamping of Large Parts (MÖHRING H-Ch., GESSLER W., KÖNIG A., NGUYEN Le T., Q. Phuc NGUYEN Q.P.), pp. 29-39
o article: Evaluation of Different Approaches to 3D Numerical Model Development of the Contact Zone Between Elementary Asperitiesand Flat Surface (MACIOLKA P., JEDRZEJEWSKI J.), pp. 40-53
o article: Simulation Roughness of the Steel Rollers' Surface Layer with Cubitron^TM II Grinding Wheels by the Quickpoint Technique (Czeslaw NIZANKOWSKI Cz., STRUZIKIEWICZ G., MATRAS A.), pp. 54-68
o article: A Data-Driven Predictive Model of the Grinding Wheel Wear Using the Neural Network Approach (LEZANSKI P.), pp.69-82
o article: Application of Bat-Cell Bio-Ambient Tests in Exhaust Gas Emissions Examinations for Euro 4 and Euro 6 Combustion Engines (KESKA A., JANICKA A.), pp. 83-90
o article: The Comparative Analysis of the Selected Construction Types of Axial Compressor Stage Including the Modal Analysis (KOZAKIEWICZ A., GRZEJSZCZAK O, LACKI T.), pp. 91-97
o article: Cutting Layer and Cutiting Forces in a 5-Axis Milling of Sculptured Surfaces Using the Toroidal Cutter (GDULA M., BUREK J.), pp. 98-122

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© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

LAYOUT DESIGN FOR FLEXIBLE MACHINING SYSTEMS IN FCIPS AND CONVERTIBILITY TO CPS MODULE IN SMART FACTORY

Yoshimi ITO^1
1Tokyo Institute of Technology, Japan

Abstract

Although being not in accordance with the original concept proposed in the "Industrie 4.0", the smart factory has been gradually applied to the practice. In contrast, we can observe that nearly all discourses, suggestions and discussions have been carried out without considering the convertibility of flexible manufacturing in FCIPS (Flexible Computer-Integrated Production Structure), which is the utmost leading facility within the industrial nation, to the CPS (Cyber Physical Systems) module in the smart factory. Admitting the powerful potentiality of the smart factory, at crucial issue is to discuss to what extent and how the technological and human resources so far accumulated in FCIPS are available for the smart factory. This paper proposes, first, the conceptual drawing of the smart factory on the basis of the concept of FCIPS, and then suggests the similarity of both the concepts. In fact, the smart factory consists of cloud computing, information communication network and CPS modules, whereas FCIPS consists of CIM, information communication network and a group of FMCs (Flexible Manufacturing Cells). Then, the paper describes the present and near future perspectives of the CPS module and FMC, especially placing the stress on machining, and asserts the convertibility of FMC for "One-off Production with Keen Machining Cost" to the CPS module. Finally, the paper summarizes the research and engineering development subjects in FCIPS and the smart factory necessary to be investigated hereafter together with detailing one leading subject, i.e. methodology to incorporate the human-intelligence into CIM.

Author Keywords :

smart factory, CPS module FCIPS, FMC, function-integrated machine tools

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

MODULAR INTELLIGENT FIXTURE SYSTEM FOR FLEXIBLE CLAMPING OF LARGE PARTS

H.-Christian MÖHRING^1,2, Werner GESSLER³, Alexander KÖNIG¹, Le Trung NGUYEN¹,Q. Phuc NGUYEN^1
1Inst. of Manufacturing Technology and Quality Management (IFQ), Otto-von-Guericke Univ. Magdeburg, Germany
²Inst. for Machine Tools (IfW), University of Stuttgart, Germany
³Innovative Fertigungstechnologie GmbH, Magdeburg, Germany

Abstract

In this work a modular intelligent fixture system for flexible clamping of large parts is presented. The fixture modules consist of a hybrid material structure involving metal frame elements and mineral casting. These modules can be combined and connected to realize fixtures adapted to the geometry of the workpiece and requirements of the machining processes. By integrated pipes and interfaces, an internal hydraulic supply and active cooling is possible even for combined modules. Temperature and acceleration sensors allow for an active thermal control and process monitoring. The modules and first test fixtures are investigated in experiments.

Author Keywords :

machine tool, modular fixture hybrid material,intelligent system

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

EVALUATION OF DIFFERENT APPROACHES TO 3D NUMERICAL MODEL DEVELOPMENT OF THE CONTACT ZONE BETWEEN ELEMENTARY ASPERITIES AND FLAT SURFACE

Pawel MACIOLKA¹, Jerzy JEDRZEJEWSKI^1
1Wroclaw University of Science and Technology, Department of Machine Tools and Mechanical Technologies, Wroclaw, Poland

Abstract

This paper presents two triaxial finite element (FE) models: a "full model" and a "quarter model", representing the contact between the specimen's rough surface and the ideally smooth and flat surface of the punch. Models have a contact zone that represents the topography of the real surface and has elastoplastic properties close to those of the real contact. The contact zone was entirely modelled on the basis of roughness measurements performed on a real milled specimen made of 5083 aluminium alloy. The development of the FE models, the stages in their refinement and the interlinking of the contact zone with the material of the specimen are described. The results of the computed deformations occurring during the specimen contact loading with the punch were compared with the experimental results. The possible causes of the observed deviations of the computer simulation results from the experimental ones were discussed. The models were used to analyse the effect of the specimens material properties, i.e. Young's modulus, yield strength, compressive strength and material hardening, on the deformations in the contact. On this basis a procedure for predicting the parameters describing the contact characteristic in cases of changes in the properties of the subsurface zone is proposed'

Author Keywords :

flat surfaces, contact, roughness, FEM, 3D model

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

SIMULATION ROUGHNESS OF THE STEEL ROLLERS' SURFACE LAYER WITH CUBITRON^TM II GRINDING WHEELS BY THE QUICKPOINT TECHNIQUE

Czeslaw NIZANKOWSKI¹, Grzegorz STRUZIKIEWICZ¹, Andrzej MATRA^1
1Production Engineering Institute of the Mechanical Faculty, Cracow University of Technology, Cracow, Poland

Abstract

This paper describes a simulation model of the process of developing steel rollers' surface layer roughness obtained with Cubitron^TM II grinding wheels by the Quickpoint technique, depending on the assumed grinding conditions. In particular, the authors present physical assumptions of the respective model, a conception and algorithm of its operation, and the results of simulation tests. The results were later verified in specific experiments by comparing the statistical average values of the selected ground steel rollers' surface roughness parameters with the values generated by simulations.

Author Keywords :

surface roughness, quickpoint grinding, Cubitron^TM II grinding wheels,

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

A DATA-DRIVEN PREDICTIVE MODEL OF THE GRINDING WHEEL WEAR USING THE NEURAL NETWORK APPROACH

Pawel LEZANSKI^1
1Lodz University of Technology, Institute of Machine Tools and Production Engineering, Lodz, Poland

Abstract

Advanced manufacturing depends on the timely acquisition, distribution, and utilization of information from machines and processes. These activities can improve accuracy and reliability in predicting resource needs and allocation, maintenance scheduling, and remaining service life of equipment. Thus, to model the state of tool wear and next to predict its remaining useful life (RUL) significantly increases the sustainability the proposed paper investigates an artificial neural network (ANN) model to predict the wear propagation process of grinding wheel and to estimate the RUL of the wheel when the extrapolated data reaches a predefined final failure value. The model building framework is based on data collected during external cylindrical plunge grinding. Firstly, usefulness of selected feature of the measured process variables to be symptoms of grinding wheel state is experimentally verified. Next, issues related to development of an effective MLP model and its use in prediction of the grinding wheel RUL is discussed.

Author Keywords :

grinding wheel wear, remaining useful life, neural network

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

APPLICATION OF BAT-CELL BIO-AMBIENT TESTS IN EXHAUST GAS EMISSIONS EXAMINATIONS FOR EURO 4 AND EURO 6 COMBUSTION ENGINES

Aleksandra KESKA¹, Anna JANICKA^1
1Wroclaw University of Science and Technology, Faculty of Mechanical Engineering, Department of Automotive Engineering, Poland

Abstract

The introduction of the subsequent European emission standards raises controversy among vehicle manufacturers and researchers. In order to meet the legal requirements, it is necessary to continually improve not only the cars but also the costly measurement facilities. In addition, current methods do not give a clear answer to the harmful effects of exhaust gases on living organisms. By using the appropriate In vitro method to directly assess the toxicity of gaseous mixtures, one can obtain simple, reliable results that can be used to validate the introduction of ever more stringent Euro standards.

Author Keywords :

in vitro method, engine exhausts, Euro standards

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

THE COMPARATIVE ANALYSIS OF THE SELECTED CONSTRUCTION TYPES OF AXIAL COMPRESSOR STAGE INCLUDING THE MODAL ANALYSIS

Adam KOZAKIEWICZ¹, Olga GRZEJSZCZAK¹, Tomasz LACKI^1
1Military University of Technology, Faculty of Mechatronics and Aviation, Warsaw, Poland

Abstract

The article concerns the issues of the scope of optimization of the gas turbine jet engine. These issues include limiting the weight and number of engine parts. One way to reduce the weight and number of components, including the compressor assembly, is to use the BLISK's replacement construction. The replacement construction should meet the strength requirement and the vibration spectrum as well. The paper presents a comparative analysis of the influence of rotational speed on the characters and the vibration frequency of the single rotor stage of the high pressure compressor. The analysis was carried out for two different design solutions of the blade-disk connection the classical and integral. The comparative analysis focused on three important from the point of view of operation, the engine operating ranges: work on the ground (idle) and work during take-off and climb the aircraft.

Author Keywords :

modal analysis, jet engine rotating parts, BLISK, optimisation

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2017 Poland

CUTTING LAYER AND CUTTING FORCES IN A 5-AXIS MILLING OF SCULPTURED SURFACES USING THE TOROIDAL CUTTER

Michal GDULA¹, Jan BUREK^1
1 Rzeszow University of Technology, Department of Manufacturing Techniques and Automation, Rzeszow, Poland

Abstract

The purpose of this article was to evaluate the significance of the influence of five- axis orientation parameters of a toroidal cutter axis and the geometrical parameters of the machined sculptured surface on the intersection of the cut layer in a 5-axis machining. An impact assessment was performed by simulating concave-convex and convex-concave surfaces using a discrete method of direct transformation in a CAD environment. It was shown that only the radius of curvature of the surface in the feed direction and the angle of the tool axis affected the change in the intersection of the cutting layer. Subsequently, experimental tests were conducted that aimed at determining the mathematical models of the influence of these important parameters on the components of the cutting force. The object of the experimental studies was a convex and concave surface of a turbine blade of Inconel 718 alloy. The R300-016B20L-08L Sandvik Coromant toroid cutter was used for the tests. Based on the results of the study it was found that the lead angle in the machining of the convex surface and concave turbine blade should be continuously varied with the change of radius of curvature in the direction of the machined surface profile.

Author Keywords :

sculptured surfaces, 5-axis milling, cutting layer, cutting forces toroidal cutter