CONTENTS

Yearbook 2013 of the Journal of Machine Engineering is covered by funding Ministry
of Science and Higher Education of Poland

JOURNAL OF MACHINE ENGINEERING

o article: Application of Fibre Composites in a Spindle Ram Design (Kulisek V., Janota M., Ruzicka M., Vrba P.), pp. 7-23
o article: Robustness and Portability of Machine Tool Thermal Error Compensation Model Based on Control of Participating Thermal Sources (Mares M., Horejs O., Hornych J., Smolik J.), pp. 24-36
o article: Extending Stability Limits by Designed-In Damping (Daghini L., Archenti A., Osterlind T.), pp. 37-48
o article: Experimental Analysis of a Machining System with Adaptive Dynamic Stiffness (Frangoudis C., Nicolescu C. M., Rashid A.), pp. 49-63
o article: Data Interoperability for Reconfigurable Manufacturing Process Monitoring Systems (Morgan J., O'Driscoll J., O'Donell G. E.), pp. 64-79
o article: Fem Modeling of Hard Turning with Consideration of Viscoplastic Asymmetry and Phase Transformation (Uhlmann E., Mahnken R., Ivanov I. M., Cheng C.), pp. 80-92
o article: Improving Machining Performance Against Regenerative Tool Chatter Through Adaptive Normal Pressure at the Tool Clamping Interface (Fu Q., Rashid A., Nicolescu C. M.), pp. 93-105
o article: Sensitivity Analysis of The Constitutive Models in Fem-Based Simulation of the Cutting Process (Niesłony P., Grzesik W.), pp. 106-116
o article: Issues in Machining of Hollow Core Honeycomb Sandwich Structures by Abrasive Waterjet Machining (Devadula S., Nicolescu M.), pp. 117-124

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JOURNAL OF MACHINE ENGINEERING

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

APPLICATION OF FIBRE COMPOSITES IN A SPINDLE RAM DESIGN

Viktor KULISEK¹, Miroslav JANOTA¹, Milan RUZICKA², Pavel VRBA^1
1Research Center of Manufacturing Technology of the Czech Technical University in Prague, Horska 3, 12800, Prague 2, Czech Republic
²Department of Mechanics, Biomechanics and Mechatronics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607, Prague 6, Czech Republic

Abstract

When compared to steel or cast iron, carbon fibre composites offer excellent tensile and bending stiffness together with significantly smaller density. Research at the Research centre of Manufacturing Technologies in Prague has been aimed at the application of composite materials in structural parts design. Case studies on spindle rams were performed focusing on the design of experimental composite spindle rams and their benchmarking with reference steel components. The cross-section of both parts was 350x350mm and the length was 1200mm. The first design was made as a thick-walled composite body with a minimal amount of steel. The goal was to achieve static stiffness comparable to a reference steel component of the same size. The second design was manufactured as a hybrid structure composed of fibre composites with cork layers and bonded steel reinforcements. The goal was to improve damping of the structural parts in comparison with the steel components. Results of stiffness and modal properties were obtained from experiments and also using FEA. Experimentally obtained damping ratios of composite and reference steel rams were compared with and without the effect of connection interfaces on damping.

Author Keywords :

carbon fibre reinforced plastics, finite element analysis, experimental modal analysis

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

ROBUSTNESS AND PORTABILITY OF MACHINE TOOL THERMAL ERROR COMPENSATION MODEL BASED ON CONTROL OF PARTICIPATING THERMAL SOURCES

Martin MARES¹, Otakar HOREJS¹, Jan HORNYCH¹, Jan SMOLIK^1
1Research Center of Manufacturing Technology of the Czech Technical University in Prague, Horská 3, 12800, Prague 2, Czech Republic

Abstract

Thermal errors caused by the influence of internal and external heat sources in machine tool structure can cause more than 50% of total machine tool inaccuracy. Therefore, research on thermal behavior of machine tool structures is crucial for successful manufacturing. This paper provides an insight into the modeling of highly nonlinear machine tool thermal errors using thermal transfer functions (TTF). The method is dynamic (uses machine tool thermal history) and its modeling and calculation speed is suitable for real-time applications. The method does not require interventions into the machine tool structure, uses very few additional gauges and solves separately each influence participating on thermal error. The paper focuses on the development of a robust thermal model sensitive to various machine tool thermal behavior nonlinearities with the help of minimum input information. Model was applied on real machine tool (portal milling centre) and was verified within a complicated electro-spindle revolution spectrum. Moreover, the said compensation model was applied on another machine tool to prove its robustness and portability among machines of the same type set and the results of the TTF model were compared with a model obtained via multiple linear regression (MLR) as a case study.

Author Keywords :

control, machine tool, thermal error, transfer function

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

EXTENDING STABILITY LIMITS BY DESIGNED-IN DAMPING

Lorenzo DAGHINI¹, Andreas ARCHENTI¹, Tomas OSTERLIND^1
1KTH Royal Institute of Technology, Machine and Process Technology, Stockholm, Sweden

Abstract

With advances in material technology come challenges to productivity. New materials are, in fact, more difficult to machine with regards to tool wear and especially machine tool stability. This paper proposes to extend the stability limits of the machining system by enhancing the structure's damping capability. The aim of the research work presented here is to introduce a unified concept based on the distribution of damping within the machining system components exploiting the dynamic properties of the existing joints. To maintain a high level of static stiffness, it was chosen to adapt hydrostatic clamping systems to the tools. Damping is designed in the structure via high damping interfaces (HDI), intentionally introduced interfaces where the damping ratio is enhanced by introduction of viscoelastic polymer metal composites between the two metallic surfaces composing the interface. In this paper HDI are introduced at two joints, between tool and turret and between turret and lathe. The tests show that the designed-in damping is effective and allows extending the stability limits of the machining system. The implementation of designed-in damping allows the end user to select the most suitable parameters in terms of productivity avoiding the hassle of tuning the devices, having to acquire a deep knowledge in structural dynamics or having to use additional control systems. In addition to this, the enhanced machine tool system becomes less sensitive to stability issues provoked by difficult-to-machine materials or even fluctuations of the work material properties that might occur in everyday production processes.

Author Keywords :

high damping interface, cutting stability, operational dynamic properties, machine tool design

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

EXPERIMENTAL ANALYSIS OF A MACHINING SYSTEM WITH ADAPTIVE DYNAMIC STIFFNESS

Constantinos FRANGOUDIS¹, Cornel - Mihai NICOLESCU¹,Amir Rashid^1
1The Royal Institute of Technology, Department of Production Engineering

Abstract

A main consideration in the operation of machine tools is vibrations occurring during the cutting process. Whether they are forced vibrations or self-excited ones, they have pronounced effects on surface quality, tool life and material removal rate. This work is an experimental study of interactions between natural characteristics, control parameters and process parameters of a machining system designed with adaptive dynamic stiffness. In order to comprehend these interactions, the effect of changes in dynamic stiffness on the system's response is examined. The system under study consists of an end-milling tool, a steel workpiece and a work holding device with controllable stiffness. Natural dynamic characteristics of the system components are determined through modal impact testing. Then the behaviour of the whole machining system is examined under both high and low cutting speed conditions by analysing vibration levels using acceleration signals acquired through a tri-axial sensor mounted on the workpiece. Cutting is performed in both directions of the horizontal plane of a CNC milling machine. In both cases the results are presented for two extremes of stiffness and damping in the work holding device. The effect of control parameters on the system's natural characteristics could be identified together with a relation between these parameters and the system's response in high and low cutting speed conditions. The high-damping configuration reduces the vibration amplitudes significantly, while the increase of pre-stress has a different effect depending on the cutting conditions.

Author Keywords :

vibrations, milling, damping, stiffness, adaptive structure

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

DATA INTEROPERABILITY FOR RECONFIGURABLE MANUFACTURING PROCESS MONITORING SYSTEMS

Jeff MORGAN¹, Eoin O'DRISCOLL¹, Garret E. O'DONNELL^1
1Mechanical and Manufacturing Engineering Department, Trinity College Dublin, Dublin 2, Ireland

Abstract

The ability for manufacturing organisation to be responsive to changing market conditions is imperative for sustainable market competitiveness, and enabling self preservation. Responsive behaviour requires the incorporation of not only robust sustainable manufacturing process chains, but the functional capacity to facilitate reconfiguration and adaption. Manufacturing process chains require process monitoring and condition based monitoring systems to achieve high accuracy manufacturing systems, sustainable production capability, and resource efficiency. The focus of this research is aimed at developing a novel data interoperability architecture to enable the creation of reconfigurable process monitoring systems. To achieve reconfigurable process monitoring capability an information communication paradigm known as agent based design is reviewed, and an emerging agent based standard known as MTConnect is also reviewed. Through this research a novel data interoperability system is developed and defined to enable dynamic data acquisition for reconfigurable process monitoring. A case study is carried out to demonstrate the validity of the architecture to achieve multi data stream unification. This case study demonstrates the ability to actively condition monitor a HURCO VM2 three axis CNC machine dynamically, through the measurement of machine energy requirements and vibration, which are examples of process variables associated with condition based machine monitoring.

Author Keywords :

agent based design, process monitoring, data interoperability

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

FEM MODELING OF HARD TURNING WITH CONSIDERATION OF VISCOPLASTIC ASYMMETRY AND PHASE TRANSFORMATION

Eckart UHLMANN¹, Rolf MAHNKEN²,Ivan Mitkov IVANOV¹,Chun CHENG^2
1Institute of Machine Tools and Factory Management, Technical University Berlin, Germany
²Chair of Technical Mechanics, University of Paderborn, Germany

Abstract

A material model for strain rate and temperature dependent asymmetric plastic behavior accompanied by phase transformation induced plasticity (TRIP) as an important phenomenon in steel production and machining processes was developed. To this end the well-known Johnson-Cook flow stress model has been extended by the concept of weighting functions considering the asymmetric plastic material behavior under tensile, compressive and torsion load. Furthermore, the extended Johnson-Cook model has been combined with the Leblond approach regarding the ductility increase by transformation induced plasticity occurring during hard turning of AISI 52100. On the basis of the theoretical approach for calculating the flow stress with consideration of the viscoplastic asymmetry, a material routine for the FEM-software DEFORM has been implemented. The material and friction model coefficients have been determined in accordance with force and surface temperature measurements during hard turning of AISI 52100. The model takes the phase transformations between martensite and austenite and the influence of externally applied stress on the austenite start temperature into account.

Author Keywords :

hard turning, finite element method, production technology, process optimization

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

IMPROVING MACHINING PERFORMANCE AGAINST REGENERATIVE TOOL CHATTER THROUGH ADAPTIVE NORMAL PRESSURE AT THE TOOL CLAMPING INTERFACE

Qilin FU¹, Amir RASHID¹,Cornel Mihai NICOLESCU^1
1Department of Production Engineering School of Industrial Technique Management, Royal Institute of Technology, SE-10044, Stocholm, Sweden

Abstract

Chatter in machining process is one of the common failures of a production line. For a cantilever tool, such as a boring bar, the rule of thumb requires the overhang length of the tool to be less than 4 times the diameter. The reason is because longer overhang will induce severe tool vibration in the form of chatter during machining. When a longer overhang than 4 times diameter is necessary for performing special machining operations, damping methods are needed to suppress tool chatter. One of the methods is the constrained layer damping method. Materials, such viscoelastic material, are applied in the vibration node regions of the structure to absorb the concentrated vibration strain energy and transform the mechanical energy to heat. With a cantilever tool clamped in a tool holder, the clamping interface is usually the vibration node region. The friction in the joint interface with low normal pressure became another source of damping and can be used for tool chatter suppression in mechanical structures. Joint interfaces are well known to possess normal pressure dependent stiffness and damping. The normal pressure's effect on the structures frequency response function had been observed by H. Akesson [1] et al, and L.Mi [2] et al. However, the direct effect of the joint interface normal pressure on machining process stability hasn't been investigated. In this paper, a cantilever tool with 6,5 overhang length to diameter ratio is investigated. The direct effect of the tool clamping interface's normal pressure on the machining process stability is studied. Three different levels of clamping normal pressure are tested with an internal turning process. The machining results indicate another adaptable solution on shop floor for suppressing tool chatter.

Author Keywords :

chatter, tool, internal turning, vibration, clamping, damping, interface

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

SENSITIVITY ANALYSIS OF THE CONSTITUTIVE MODELS IN FEM-BASED SIMULATION OF THE CUTTING PROCESS

Piotr NIESLONY¹, Wit GRZESIK^1
1Faculty of Mechanical Engineering, Opole University of Technology, 5 Mikołajczyka Street, Opole 45-271, Poland

Abstract

The paper considers the problem of the influence of constitutive model parameters on the results of FEM-based simulation of the orthogonal cutting process using C45 (AISI 1045) carbon steel and multilayer-coated carbide tool. The simulations were based on the power constitutive law (PL) with a special consideration of the temperature-related thermal influences. The sensitivity analysis performed concerns the models proposed by Özel and Kalhori and own data in the form of multi-regressive equations for the substrate and coating components that were applied. In particular, the values of n exponent were varied in order to assess the simulation results. The FEM simulations include the average interface temperature, the distribution of temperature on the rake face and within the wedge body, as well as cutting forces. By modifying the PL parameters, the prediction errors lower than 15% were obtained.

Author Keywords :

FEM, constitutive models, simulation, cutting process

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

ISSUES IN MACHINING OF HOLLOW CORE HONEYCOMB SANDWICH STRUCTURES BY ABRASIVE WATERJET MACHINING

Sivasrinivasu DEVADULA¹, Mihai NICOLESCU^1
1Department of Production Engineering, KTH - The Royal Institute of Technology, Sweden

Abstract

Machining of hollow core honeycomb sandwich materials is a challenging job as the mechanical properties of various layers (skin, core) are quite dissimilar, and the conventional solid cutting tool experiences a sudden change of conditions while machining that might lead to damage on the tool/part. Although, abrasive waterjets (AWJs) is highly efficient in the machining of advanced composite materials due to their unique characteristics, efficient machining of sandwich structures by AWJs needs many challenges to be addressed. This work presents various issues observed in AWJ machining of carbon- and glass- fiber skin based, aluminum sandwich structure composite materials, and the limitations of AWJs in processing these exotic materials. Finally, possible strategies for efficient machining of honeycomb structures were proposed for future investigation.

Author Keywords :

abrasive waterjet, machining, honeycomb sandwich material

JOURNAL OF MACHINE ENGINEERING

o article: Knowledge Base And Assumptions for Holistic Modelling Aimed ft Reducing Axial Errors of Complex Machine Tools (Jedrzejewski J., Kwasny W.), pp.7-25
o article: Product Configuration Using Knowledge Based System (Kutschenreiter-Praszkiewicz I.), pp. 26-35
o article: Chatter Stability Investigation in Micro-Milling (Matuszak M., Powalka B., Kochmanski P.), pp. 36-45
o article: Comparison of Surface Textures Produced by Finish Cutting, Abrasive and Burnishing Operations in Terms Of Their Functional Properties (Grzesik W., Zak K.), pp. 46-58
o article: Numerical Modelling Of Innovative Manufacturing Processes with Induced Strain Path Changes (Muszka K., Madej L., Graca P., Majta J.), pp. 59-68
o article: Operational Modal Analysis During Milling of Workpiece, Fixed on a Stiffness Controllable Joint (Osterlind T., Frangoudis C., Archenti A.), pp. 69-78
o article: Statistical Evaluation of Impact Factors to the Energy Consumption of Machine Tools (Wittstock V., Kolouch M., Paetzold J.), pp. 79-91
o article: Material Recycling of Tyres by Wather Jet Method (Holka H., Jarzyna T., Matuszewski M., Musial J.), pp. 92-102

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JOURNAL OF MACHINE ENGINEERING

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

KNOWLEDGE BASE AND ASSUMPTIONS FOR HOLISTIC MODELLING AIMED AT REDUCING AXIAL ERRORS OF COMPLEX MACHINE TOOLS

Jerzy JEDRZEJEWSKI¹, Wojciech KWASNY^1
1Institute of Production Engineering and Automation, Wroclaw University of Technology, Poland

Abstract

The paper presents the idea and need for the holistic modelling of machine tools. The complexity of such modelling is illustrated for a 5-axis machining centre. The need to model errors in the controllable axes of machine tools with rotational and linear motion drives is indicated. The physical dependences having a bearing on the state of deformations produced by temperature and dynamic forces, as well as the assumptions and computational modelsof shift generation in the high-speed bearing sets of spindles, and models of the behaviour of the ball screw are presented. Moreover, the results of experimental studies of the thermal behaviour of linear motor sets and guideways with rolling blocks are reported.

Author Keywords :

holistic model, machine tool, power losses, error

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

PRODUCT CONFIGURATION USING KNOWLEDGE BASED SYSTEM

Izabela KUTSCHENREITER-PRASZKIEWICZ¹,
¹University of Bielsko-Biala, 43-300 Bielsko-Biala, Willowa 2, ipraszkiewicz@ath.bielsko.pl, http://www.ath.bielsko.pl Poland

Abstract

Product configuration is focused on achieving customer satisfaction. Configuration methods should use previous experiences related to product changes One of the methods of storing experiences is elaboration of knowledge bases with the use of proper knowledge representation method. In the paper identification of customer needs was discussed, as well as product decomposition methods were presented. The Quality Function Deployment (QFD) method was suggested to be applied as a product and process data integration tool, where engineering characteristic of a product was combined with its trade characteristic. The paper shows that thanks to the application of knowledge based system in production preparation it is possible to support decision making connected with product selection and evaluation for a particular customer.

Author Keywords :

product, configuration,knowledge, quality,method

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

CHATTER STABILITY INVESTIGATION IN MICRO-MILLING

Marcin MATUSZAK¹, Bartosz POWALKA¹,Pawel KOCHMANSKI^1
1Department of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology, al. Piastów 19, 70-310 Szczecin, Poland

Abstract

The paper presents investigation under chatter stability in micromilling process. To determine the impact of micromilling machine dynamic properties, impulse test of micromilling tool was carried out. Due to high participation of ploughing in micromilling process the regenerative effect in comparison to conventional milling can be reduced or lead to frictional vibration. Series of cutting tests for variable cutting speed, feed per tooth and cutting depth were performed to verify these assumptions. During the tests cutting forces and accelerations, both on machine spindle and workpiece were measured. Performed milling tests show that the vibration occurs at highest depth of cut and at lowest feed rate. This leads to the conclusion that reason of vibration could be friction between tool and workpiece.

Author Keywords :

micro-milling, impact test, vibration

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

COMPARISON OF SURFACE TEXTURES PRODUCED BY FINISH CUTTING, ABRASIVE AND BURNISHING OPERATIONS IN TERMS OF THEIR FUNCTIONAL PROPERTIES

Wit GRZESIK¹, Krzysztof ZAK^1
1Faculty of Mechanical Engineering, Opole University of Technology, 5 Mikolajczyka Street, Opole 45-271, Poland

Abstract

The purpose of this research is to asses the functionality of surfaces produced by CBN hard turning, ball burnishing and superfinishing for improving the surface finish of parts made of high-strength, low alloy 41Cr4 steel with a hardness of about 57 HRC. Machined surfaces were characterized usin 3D scanning techniques. A set of 3D roughness parameters and real 3D surface topographies produced by the above-mentioned machining operations were estimated and determined.This investigation confirms that sequential processes based on initial CBN hard turning allows producing surfaces with better service properties.The main conclusion is that this sequential technology can partly eliminate grinding operations when hard machining is not enough to produce the desired surface finish.

Author Keywords :

hard turning, burnishing,superfinish, surface texture, functional properties

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

NUMERICAL MODELLING OF INNOVATIVE MANUFACTURING PROCESSES WITH INDUCED STRAIN PATH CHANGES

Krzysztof MUSZKA¹, Lukasz MADEJ¹,Paulina GRACA¹,Janusz MAJTA^1
1AGH University of Science and Technology, Mickiewicza 30, 30-059 Krakow, Poland

Abstract

A review of various bulk metal forming processes that take into account influence of strain path changes on material flow is presented in this paper. Particular attention is put on computer aided design of innovative angular accumulative drawing (AAD) operation. Research in the area of development of metal forming processes taken advantage of strain path phenomena is conducted in many scientific laboratories as the strain patch change effect influences many crucial properties of the deformed material. As a result it provides a possibility of forming materials, which are e.g. difficult to form in a conventional manner. Advantages and limitations of the AAD process are summarized and presented in this work. Difficulties in development of the complex rheological model that takes in to account strain path changes in the deformed material are also presented and discussed.

Author Keywords :

strain path, accumulative angular drawing, FE modelling

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

OPERATIONAL MODAL ANALYSIS DURING MILLING OF WORKPIECE, FIXED ON A STIFFNESS CONTROLLABLE JOINT

Tomas OSTERLIND¹, Constantinos FRANGOUDIS¹,Andreas ARCHENTI^1
1KTH Royal Institute of Technology, Department of Production Engineering, Stockholm, Sweden

Abstract

Vibration in metal cutting processes has been studied to a great extent resulting in for instance stability lobe diagrams under which stable machining parameters can be selected. One limitation of accurately estimated stability diagrams is the change in process and dynamic characteristics of the machine tool under operation. The machine tool dynamic response is often analysed with experimental modal analysis under off operational conditions. One drawback with this approach is the large number of measurements required to fully describe a machine tool and workpiece in different positions and time of machining. Another drawback is that the change of dynamiccharacteristics under operation is excluded. Operational modal analysis has been applied in machining under different conditions resulting in successfully improved stability lobe prediction. This research includes operational modal analysis of the workpiece, fixed on a stiffness controllable joint and stability prediction to stress the importance of various machining conditions.

Author Keywords :

machine tool, operational modal analysis machining stability

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

STATISTICAL EVALUATION OF IMPACT FACTORS TO THE ENERGY CONSUMPTION OF MACHINE TOOLS

Volker WITTSTOCK¹, Martin KOLOUCH¹,Jorg PAETZOLD^1
1Institute of Machine Tools and Production Processes, University of Technology Chemnnitz, Germany

Abstract

In this paper, a method for the evaluation of the energy consumption of machine tools is presented. For this purpose, the energy consumption of various machine tools has been investigated experimentally. In order to increase the evaluation basis, measured values of energy consumption were also taken from literature. The evaluation contains an analysis of various factors concerning the productivity and the size of the investigated machine tools. This analysis is capable of detecting the impact factors to increase the energy-efficiency of production systems. It can further reduce the effort required for data acquisition when various machine tools are compared.

Author Keywords :

energy efficiency, machine tool, statistical analyses

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

MATERIAL RECYCLING OF TYRES BY WATHER JET METHOD

Henryk HOLKA¹, Tomasz JARZYNA¹,Maciej MATUSZEWSKI¹, Janusz MUSZIAL^1
1University of Technology and Life Sciences, Faculty of Mechanical Engineering, Bydgoszcz, Poland

Abstract

In this article there has been presented an innovative method of tire material recycling with the use of water jet technology including calculation of mass balance of the jetted water, velocity of the water flowing out of a nozzle, demand for power to drive the pump, or the energy consumption unit indicator. Moreover, an analysis of the dynamic impact of water jet on the tire has been made. Successive stages of the research, performed by the authors in order to develop the final model and construct the machine for tire recycling, have been described. In the final section of the paper there are calculation results and conclusions.

Author Keywords :

recycling, water jet method, used tyres

JOURNAL OF MACHINE ENGINEERING

o article: Position Paper - Fundamental Issues in Self-Excited Chatter In Turning(Ito Y.), pp. 7-25
o article: Fundamental Issues in Self-Excited Chatter in Grinding (Entwistle R., Stone B.), pp. 26-50
o article: Multiple Regenerative Effect Governing Chatter Behaviour after Onset (Sato H.), pp. 51-76
o article: Review of Potential Advantages and Pitfalls of Numerical Simulation of Self-Excited Vibrations (Jemielniak K., Wypysinski R.), pp. 77-90
o article: Dynamic Parameter Identification in Nonlinear Machining Systems (Nicolescu M., Archenti A.), pp. 91-116
o article: Avoiding Chatter by Means of Active Damping Systems for Machine Tools (Brecher C., Baumler S., Brockmann B.), pp. 117-128
o article: Dynamic Characteristics of Linear Rolling Bearings for Machine Tools (Sakai Y., Tsutsumi M.), pp. 129-142

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JOURNAL OF MACHINE ENGINEERING

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

POSITION PAPER - FUNDAMENTAL ISSUES IN SELF-EXCITED CHATTER IN TURNING

Yoshimi ITO^1
1Tokyo Institute of Technology, Japan

Abstract

Although observing a considerable number of new interesting behavior in dynamic states of machining, nearly all researches into the chatter vibration have been based on those conducted by Tobias, Tlusty and Merritt. In fact, we have established myriad remedies for the chatter suppression on the strength of their achievements; however, some crucial issues remain still in uncertainties, e.g., validity of penetration effects, definition duly what are the essential features of the chatter vibration. This position paper describes the facing problems of the chatter vibration in detail, aiming at the establishment of a generalized chatter loop. By this chatter loop, we may unveil synthetically the deterioration and improvement of the stability chart by all the influencing attributes, such as forced vibration and non-linearity within the machine-tool-work system.

Author Keywords :

turning, cutting, parametric vibration, chatter, stability

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

FUNDAMENTAL ISSUES IN SELF-EXCITED CHATTER IN GRINDING

Rodney ENTWISTLE¹, Brian STONE^1
1Curtin University, Western Australia

Abstract

The modelling of chatter in grinding is more complex than for metal cutting. This is because the number of parameters that influence the onset of chatter in grinding is daunting. Also, unlike metal cutting, the growth of chatter in grinding may take a significant time and so growth rates are also important. Initially the modelling of grinding chatter was simply an extension of that already developed for metal cutting. However this was soon found to be inadequate and the models were increased in complexity to include improved grinding force models the contact stiffness of the wheel and regeneration of surface waves on both the work and wheel. Some solutions to chatter in grinding were also proposed. Most notably these included the use of varying speed and flexible grinding wheels. This position paper re-visits the almost universal assumption that grinding chatter is always regenerative. It is shown that a grinding force model for oscillating conditions, that has been experimentally confirmed, indicates that both torsional vibration and non-regeneration need to be considered. The consequences for current methods of chatter elimination are discussed.

Author Keywords :

chatter, grinding, vibration, contact stiffness, regeneration

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

MULTIPLE REGENERATIVE EFFECT GOVERNING CHATTER BEHAVIOUR AFTER ONSET

Hisayoshi SATO^1
1University of Tokyo, Japan

Abstract

Chatter is the self-excited vibration that occurs during cutting. The entire structure of a self-excited vibration comprises two core mechanisms, i.e., stability limit and sustained vibration with finite amplitude after onset. The latter mechanism remained unnoticed until the discovery of the multiple regenerative effect (MRE) in 1980. However, its effects have not yet been recognized correctly. This paper summarizes the problems that could be resolved by considering the MRE in the analysis from the theoretical and practical viewpoints. In conventional stability limit analyses,tool traces never intersect; however, after the onset of chatter in an actual system, traces immediately intersect. This resultsin tool-workpiece separation, chip thickness variation during the separation period, and chip breakage. A solution for equation of motion considering the MRE agrees well with chatter behaviour in actual applications. In addition, the solution yields the phase relationship between the displacement of work motion and the cutting force, although this relationship is not considered in the equation of motion. Further, the relationship between the penetrating cutting speed and the resistive force, confirmed experimentally, is introduced in equation of motion, which verifies the widening of the stability region at low cutting speeds.

Author Keywords :

machine tools, chatter, vibration, regenerative effect

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

REVIEW OF POTENTIAL ADVANTAGES AND PITFALLS OF NUMERICAL SIMULATION OF SELF-EXCITED VIBRATIONS

Krzysztof JEMIELNIAK¹, Rafal WYPYSINSKI^1
1Warsaw University of Technology, Faculty of Production Engineering, Poland

Abstract

Machining stability is one of the most important factors influencing the geometrical and dimensional accuracy of the machined parts. Regenerative chatter is a major limitation to the productivity and quality of machining operations due to poor surface finish and faster tool wear. In general there are two methods of stability analysis: solution of differential equations of the system in frequency domain or numerical simulation in time domain. Fast and easy calculations in the frequency domain are possible using a simplified linear model of cutting process. Important limitations of these methods are difficult or impossible considering of changes of dynamic cutting force coefficients and dynamic characteristic of a process. Numerical simulation has not these limitations and regards many specific phenomena of the cutting processes, therefore it is often used in the stability analysis. The paper presents main advantages of numerical simulation, which differentiates it from the analytical solutions, as well as some inevitable difficulties and limitations.

Author Keywords :

numerical simulation, nonlinear chatter, cutting dynamic

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

DYNAMIC PARAMETER IDENTIFICATION IN NONLINEAR MACHINING SYSTEMS

Mihai NICOLESCU¹, Andreas ARCHENTI^1
1KTH, Royal Institute of Technology

Abstract

The demand for enhanced performance of production systems in terms of quality, cost and reliability is ever increasing while, at the same time, there is a demand for shorter design cycles, longer operating life, minimisation of inspection and maintenance needs. Experimental testing and system identification in operational conditions still represent an important technique for monitoring, control and optimization. The term identification refers in the present paper to the extraction of information from experimental data and is used to estimate operational dynamic parameters for machining systems. Such an approach opens up the possibility of monitoring the dynamics of machining systems during operational conditions, and can also be used for control and/or predictive purposes The machining system is considered nonlinear and excited by random loads. Parametric and nonparametric techniques are developed for the identification of the nonlinear machining system and their application is demonstrated both by numerical simulations and in actual machining operations. Discrimination between forced and self-excited vibrations is also presented. The ability of the developed methods to estimate operational dynamic parameters ODPs is presented in practical machining operations.

Author Keywords :

machining system, dynamic parameters, white noise excitation, self-excited vibration

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

AVOIDING CHATTER BY MEANS OF ACTIVE DAMPING SYSTEMS FOR MACHINE TOOLS

Christian BRECHER¹, Stephan BAUMLER¹, Birk BROCKMANN^1
1WZL - Laboratory for Machine Tools and Production Engineering, Aachen, Germany

Abstract

Chatter in machining processes is strong dependent on the dynamic compliance behaviour of the machine tool and workpiece. The critical cutting depth where chatter occurs is in inverse proportion to the absolute value of the negative real part of the complex dynamic compliance response function of the machine tool. Therefore, while designing a machine tool, its dynamic behaviour should be investigated and optimized, e.g. by using the finite element method. If further design optimization are not possible, active damping system might help avoiding chatter of the machine tool. Active damping systems can compensate the dynamic displacements between tool centre point of the machine tool and workpiece by applying dynamically correlated external energ (e.g. compensation forces) onto the machine structure. Next to an explanation of the general idea and systemizatio of active damping systems, this paper gives examples of recent research activities in the field of active damping systems for machine tools of the Laboratory for Machine Tools and Production Engineering (WZL) of Aachen University, Germany. The main challenges while designing active damping systems for machine tools are carved out.

Author Keywords :

machine tools, milling, grinding, boring, chatter, active damping system

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

DYNAMIC CHARACTERISTICS OF LINEAR ROLLING BEARINGS FOR MACHINE TOOLS

Yasunori SAKAI¹, Masaomi TSUTSUMI^2
1Tokyo Institute of Technology, Department of Mechanical and Control Engineering
²Tokyo University of Agriculture and Technology, Institute of Engineering

Abstract

The present paper proposes a method for evaluating the dynamic characteristics of a single linear rolling bearing subjected to a radial force and a bending moment. In order to evaluate the damping of a rail-carriage system, a rectangular column with a flange is fixed to the carriage by bolts, and the free end of the column is excited by an impulse hammer in the horizontal (x), lateral (y), and radial (z) directions. The response is detected by an accelerometer mounted to the flange of the column. Both force and acceleration are input to an FFT analyzer, and the frequency response function (FRF) is calculated. The damping capacity in each direction is evaluated as a modal damping ratio, which is calculated based on the FRF. As a result, the damping ratio of the vibration mode in the feed (x) direction is higher than those of the other vibration modes. In addition, the influence of the nonlinearity of the linear rolling bearings on the dynamic characteristics is investigated. The results reveal that the dynamic characteristics of the linear rolling bearings depend on the excitation direction.

Author Keywords :

damping, linear rolling bearing, response function, dynamic

JOURNAL OF MACHINE ENGINEERING

o article: Logistics in Production Processes (Michlowicz E.), pp. 5-17
o article: Elements of Software Integration of Production Systems in Industrial Product Control and Didactics (Nieciag H., Dudek P.), pp. 18-34
o article: Dependency of the Technological Quality of Elements Made from an Aluminum Alloy on Their Shape in the Water Jet Machining (Wantuch E., Kudelski R.,Nieciag H.), pp. 35-46
o article: Machining Study of a Part Consisting of a Sphere Inside a Cube (Jablonski W.), pp. 47-56
o article: Analysis of Kinematic and Force Parameters of the Die-Forging Process Performed on a CrNiN Alloy {Swiatonowski A., Szostak J.), pp. 57-67
o article: The Problem of Energy-Consuming Processes in the Planning of Modern Manufacturing Technologies (Rusek P., Wantuch E., Zagorski K.), pp. 68-76
o article: Preparation and Recycling of Carbon Containing Composites (Zagorski K., Rusek P.), pp. 77-86
o article: Investigation of Ball Screws for Feed Drive (Sobolewski J.), pp. 86-95

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JOURNAL OF MACHINE ENGINEERING

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

LOGISTICS IN PRODUCTION PROCESSES

Edward MICHLOWICZ^1
1AGH University of Science and Technology, Cracow, Poland

Abstract

Integration of production planning and logistics is currently becoming more and more widespread in many companies. The role and tasks of production logistics in a company are dependent on many factors as well as on an appropriate definition of logistics. The development of the concept of the supply chain has resulted in a broader view of logistics. The primary goal of production logistics can be formulated as expansion of the capabilities for the implementation and reliability of deliveries with the lowest logistical and production costs. In such an approach production systems are those in which input quantities are temporally and spatially transformed into products. With logistical supply networks at the input and distribution networks at the output of the system, production and logistics are closely linked. The approach proposed within the framework of Lean enterprises is interesting. It requires first defining a stream of values, then mapping and improving it. The methods appearing in the literature under the name Lean toolbox can be used to improve a company's productivity indices.

Author Keywords :

production logistics, lean toolbox, TPM, VSM methods

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

ELEMENTS OF SOFTWARE INTEGRATION OF PRODUCTION SYSTEMS IN INDUSTRIAL PRODUCT CONTROL AND DIDACTICS

Halina NIECIAG¹, Piotr DUDEK^1
1AGH University of Science and Technology, Cracow, Poland

Abstract

The article presents the method that is used to educate students pursuing a course in Machine Design Technology. The implementation of contactless measurement technology, which is becoming increasingly popular in industrial product control, was described. The sample part subjected to dimensional control was the fastening block of a 3R system electrode. Dimensional control in order to map some geometrical features of the part was conducted on a station equipped with a coordinate measuring arm and included contact-free verification of exterior dimensions.

Author Keywords :

part inspection, coordinate instruments, optical scanner

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

DEPENDENCY OF THE TECHNOLOGICAL QUALITY OF ELEMENTS MADE FROM AN ALUMINUM ALLOY ON THEIR SHAPE IN THE WATER JET MACHINING

Edward WANTUCH¹, Rafal KUDELSKI¹,Halina NIECIAG^1
1AGH University of Science and Technology, Cracow, Poland

Abstract

The problem of the technological quality of elements is one of the primary problems of modern machine production. In many cases, elements are made from new construction materials with specific properties considered to have poor machinability in cases where conventional technologies are applied. Thus, there is a need to identify the capabilities of new technologies, including the technology of cutting with a high-pressure abrasive water jet for the production of elements made of Al alloys, while observing qualitative machining requirements. This paper presents the results of studies of the accuracy of production of elements with a complex shape made of a 2017A alloy (PA6) and of studies of the coarseness of obtained surfaces depending on the pressure of the water jet, cutting advance rate, and the amount of dosed abrasive for a constant thickness of the element. The measure of the accuracy of production, independent of dimensional accuracy, was assumed to be the size of chamfering on the side surface of the cut element caused by a specific mechanism of material decohesion occurring under the influence of water jet technology. In cases where Al alloys are cut, depending on assumed conditions, it is possible to shape the side surface of an element with a positive, negative, or neutral (zero) wall inclination (side of the element). In the process of cutting, specific errors in the shape of the element occur and appear on curved fragments of the object or in discontinuous areas of the profile (e.g. transition from a straight fragment to an arc fragment); this is caused by a shift in the exit of the high-pressure abrasive water jet from the object relative to the point of entry. Consequently, selection of cutting parameters for the water jet method for elements with complex shapes is, in essence, a compromise between the obtained inclination of the wall of the processed element and the required surface coarseness, and between the required (acceptable) inclination of the wall of the element or lack thereof and the obtained coarseness of the element's surface. Thus, in the outlined problem, it is not possible to simultaneously obtain two satisfactory criteria quantities of element quality, that is, accuracy of shape and requisite coarseness of the surface of the machined element, if the water jet method is applied for the purpose of machining Al alloys.

Author Keywords :

water jet, machining, quality, aluminum alloy

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

MACHINING STUDY OF A PART CONSISTING OF A SPHERE
INSIDE A CUBE

Wojciech JABLONSKI^1
1AGH University of Science and Technology, Cracow, Poland

Abstract

This paper pertains to the execution of a part consisting of a sphere situated inside a cube on a CNC milling machine tool. The sphere is freely situated, i.e. it has full freedom of movement within the cube. However it is not possible to remove it from the cube, because its diameter exceeds the length of the cube wall. The hypothesis posed in this paper is that optimal utilisation of technological processing capabilities in combination with geometrical and technological problem analysis enables a significant expansion in the range of details acknowledged as possible to produce. A method of analysis of a technological problem posed in this way was proposed, as a result of which the technology for production of this part was developed, and the final effect presented in the form of the produced detail. This paper shows that the condition for success is the proper selection of technological factors (machine tool, tools, method of fastening) and conceptual and informational factors (geometrical analysis, correct use of CNC control, optimal utilisation of CAD/CAM software for generation of the control program).

Author Keywords :

CNC processing, sphere in cube, milling

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

ANALYSIS OF KINEMATIC AND FORCE PARAMETERS OF THE DIE?FORGING PROCESS PERFORMED ON A CrNiN ALLOY

Andrzej SWIATONOWSKI¹, Janusz SZOSTAK^1
1AGH University of Science and Technology, Faculty of Mechanical Engineering and Robotics, Cracow, Poland

Abstract

This article presents the results of studies of simulations of die forging of a drive shaft for small and medium watercraft. The formed material is a chromium and nickel alloy endogenically modified with nitrogen. Numerical simulations were carried out using the DEFORM-3D program, by means of which a map of mean stresses, temperature, deformation intensity, and cracking according to the Cockroft-Latham model were obtained. The results of the conducted studies will enable selection of the appropriate technological parameters in the process of forging CrNiN alloys.

Author Keywords :

forging, CrNiN alloy, FEM

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

THE PROBLEM OF ENERGY-CONSUMING PROCESSES IN THE PLANNING OF MODERN MANUFACTURING TECHNOLOGIES

Piotr RUSEK¹, Edward WANTUCH²,Krzysztof ZAGORSKI^2
1Institute of Advanced Manufacturing Technology, Cracow, Poland
²AGH University of Science and Technology, Faculty of Mechanical Engineering and Robotics, Cracow, Poland

Abstract

Despite the application of a series of universally acknowledged procedural principles, the manufacture of elements is a process in which the skills and professional experience of the planner are of continued importance. This leads to a certain degree of subjectivity in evaluation as well as to arbitrariness and variety in the solutions presented by process engineers. By introducing evaluations of the energy consumption of processes as an additional criterion, it is possible to make planning more objective, to reduce arbitrariness in the selection of production technologies, and to reduce energy consumption and manufacturing costs. An example of the application of energy consumption indices in the design of a selected manufacturing process is given in this article.

Author Keywords :

energy consumption, planning, technological process

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

PREPARATION AND RECYCLING OF CARBON CONTAINING COMPOSITES

Krzysztof ZAGORSKI¹, Piotr RUSEK^2
1AGH University of Science and Technology, Faculty of Mechanical Engineering and Robotics, Cracow, Poland
²The Institute of Advanced Manufacturing Technology, Cracow, Poland

Abstract

Composites based on anthracite grains and carbon scrap containing also two mirror components were investigated. A milling machine allowing cutting speeds in the 100-400mm/min range connected to a piezoelectric dynamometer and a video camera was used. The debris formed was screened through sieves and chips with sizes larger than 1 mm can be recycled. Cutting resistance of the composite depends on the local distribution of the carbon scrap phase.

Author Keywords :

carbon composites, machining, scrap recycling

© Copyright by, Editorial Institution of the Wroclaw Board of Scientific Technical Societies Federation NOT, Wroclaw 2013, Poland

INVESTIGATION OF BALL SCREWS FOR FEED DRIVE

Jerzy Z. SOBOLEWSKI^1
1Institute of Machine Design Fundamentals, Warsaw University of Technology, Warsaw, Poland,

Abstract

The paper presents a method which enables the ball screw choice for machine tools feed drive with increasing cutting speed. It has been proven, that when the velocity deflection in the ball/balltrack area of the transitive phase of ball motion reaches a certain level, the repetitive shocks (impact forces) are generated. Digital simulation of these forces for variable length screws shaft and ball diameters in function of rotational speed has been performed. The research proves that impact forces increase not only as rotational velocity increases, but also with the increase of the ball diameters. The cases of the harmful accordance of the feed drive resonance vibrations with the frequency of the balls entering the load have been examined.

Author Keywords :

ball screws, machine tools, rigidity, impact forces