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Frangoudis, ConstantinosORCID iD iconorcid.org/0000-0003-0219-1667
Publications (6 of 6) Show all publications
Frangoudis, C., Rashid, A. & Nicolescu, C. M. (2017). Development and analysis of a consciously designed Joint Interface Module for improvement of a machining system's dynamic performance. The International Journal of Advanced Manufacturing Technology, 88(1-4), 507-518
Open this publication in new window or tab >>Development and analysis of a consciously designed Joint Interface Module for improvement of a machining system's dynamic performance
2017 (English)In: The International Journal of Advanced Manufacturing Technology, ISSN 0268-3768, E-ISSN 1433-3015, Vol. 88, no 1-4, p. 507-518Article in journal (Refereed) Published
Abstract [en]

Machining vibrations and dynamic instability of machine tools is an important consideration in machining systems. Common approaches for improving their dynamic performance target either the process, or intelligent, yet complex control systems with actuators. Given that machine tools' dynamic characteristics are largely defined by the characteristics of the joints, this article proposes a novel concept, attempting to create a new paradigm for improving the dynamic behaviour of machine tools-introducing modular machine tools components (Joint Interface Modules-JIMs) with joints deliberately designed for increasing dynamic stiffness and enhancing damping with the use of viscoelastic materials. Through a systematic model-based design process, a prototype replicating a reference tool holder was constructed exploiting viscoelastic materials and the dynamic response of the machining system was improved as a result of its introduction; in machining experiments, the stability limit was increased from around 2 mm depth of cut to 4 mm depth of cut, without compromising the rigidity of the system or changing the process parameters. The article also includes the results of investigations regarding the introduction of such prototypes in a machine tool and discusses the shortcomings of the stability lobe diagrams as a method for evaluating the performance of machine tool components with viscoelastically treated joints.

Place, publisher, year, edition, pages
Springer London, 2017
Keywords
Machine tool, Milling, Vibrations, Joints, Damping, Viscoelastic
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-202444 (URN)10.1007/s00170-016-8781-3 (DOI)000392308400044 ()2-s2.0-85009726941 (Scopus ID)
Funder
Swedish e‐Science Research CenterEU, FP7, Seventh Framework Programme, 260048XPRES - Initiative for excellence in production research
Note

QC 20170306

Available from: 2017-03-06 Created: 2017-03-06 Last updated: 2017-11-29Bibliographically approved
Frangoudis, C. (2014). Controlling the dynamic characteristics of machining systems through consciously designed joint interfaces. (Licentiate dissertation). Stockholm: KTH Royal Institute of Technology
Open this publication in new window or tab >>Controlling the dynamic characteristics of machining systems through consciously designed joint interfaces
2014 (English)Licentiate thesis, monograph (Other academic)
Abstract [en]

The precision of machining systems is ever increasing in order to keep up with components’ accuracy requirements. At the same time product variants areincreasing and order quantities are decreasing, which introduces high demands on the capability of machining systems. The machining system is an interaction between the machine tool structure, the process and the control system and is defined in terms of capability by the positional, static, dynamic and thermal accuracy. So far, the control of the machining system, in terms of static and dynamic stability is process based which is often translated into sub-optimum process parameters and therefore low productivity.This thesis proposes a new approach for control of the machining systemwhich is based on the capability to control the structural properties of themachine tool and as a result, controlling the outcome of the machining process.The control of the structural properties is realized by carefully designed Joint Interface Modules (JIMS). These modules allow for control of the stiffness and damping of the structure, as a result of tuning the contact conditions on the interface of the JIM; this is performed by control of the pre-load on the interface,by treatment of the interface with damping enhancing materials, or both. The thesis consists of a presentation of the motivation behind this work, the theoretical basis on which the proposed concept is based and a part describing the experimental investigations carried out. Two prototype JIMs, one for a milling process and one for a turning process were used in the experimental investigations that constitute the case studies for examining the validity of the proposed concept and demonstrating its applicability in a real production environment.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2014. p. viii, 97
Series
TRITA-IIP, ISSN 1650-1888 ; 14:07
Keywords
Production, machine tool, machining system control, joint interfaces, JIM, stiffness, damping, vibrations, machining process, milling, turning, deflections, accuracy, dynamic response
National Category
Production Engineering, Human Work Science and Ergonomics
Identifiers
urn:nbn:se:kth:diva-146306 (URN)978-91-7595-201-7 (ISBN)
Presentation
2014-06-13, Sal M312, Brinellvägen 68, KTH, Stockholm, 13:00 (English)
Opponent
Supervisors
Projects
EU FP7 POPJIM
Note

QC 20140611

Available from: 2014-06-11 Created: 2014-06-11 Last updated: 2014-06-11Bibliographically approved
Frangoudis, C., Nicolescu, C.-M. & Rashid, A. (2013). Experimental Analysis of a Machining System with Adaptive Dynamic Stiffness. Journal of Machine Engineering, 13(1), 49-63
Open this publication in new window or tab >>Experimental Analysis of a Machining System with Adaptive Dynamic Stiffness
2013 (English)In: Journal of Machine Engineering, ISSN 1895-7595, Vol. 13, no 1, p. 49-63Article in journal (Refereed) Published
Abstract [en]

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 lifeand 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. Inorder to comprehend these interactions, the effect of changes in dynamic stiffness on the system’s response isexamined. The system under study consists of an end-milling tool, a steel workpiece and a work holding devicewith controllable stiffness. Natural dynamic characteristics of the system components are determined throughmodal impact testing. Then the behaviour of the whole machining system is examined under both high and lowcutting speed conditions by analysing vibration levels using acceleration signals acquired through a tri-axialsensor mounted on the workpiece. Cutting is performed in both directions of the horizontal plane of a CNCmilling machine. In both cases the results are presented for two extremes of stiffness and damping in the workholding device. The effect of control parameters on the system’s natural characteristics could be identifiedtogether with a relation between these parameters and the system’s response in high and low cutting speedconditions. The high-damping configuration reduces the vibration amplitudes significantly, while the increaseof pre-stress has a different effect depending on the cutting conditions.

Place, publisher, year, edition, pages
Wroclaw, Poland: Wroclawska Rada Federacji Stowarzyszen Naukowo-Technicznych NOT, 2013
Keywords
vibrations, milling, damping, stiffness, adaptive structure
National Category
Production Engineering, Human Work Science and Ergonomics
Research subject
SRA - Production
Identifiers
urn:nbn:se:kth:diva-140719 (URN)
Projects
EU FP7 PoPJIM
Funder
XPRES - Initiative for excellence in production research
Note

QC 20140205

Available from: 2014-01-31 Created: 2014-01-31 Last updated: 2017-03-29Bibliographically approved
Frangoudis, C., Fu, Q., Ur Rashid, M. M. M., Nicolescu, C. M. & Rashid, A. (2013). Experimental analysis of the CNx nano-damping material’s effect on the dynamic performance of a milling process. In: Archenti, Andreas; Maffei, Antonio (Ed.), Proceedings of the International Conference on Advanced Manufacturing Engineering and Technologies: . Paper presented at Proceedings of the International Conference on Advanced Manufacturing Engineering and Technologies NEWTECH 2013; Stockholm, Sweden, 27-30 October, 2013 (pp. 293-302). Stockholm: KTH Royal Institute of Technology
Open this publication in new window or tab >>Experimental analysis of the CNx nano-damping material’s effect on the dynamic performance of a milling process
Show others...
2013 (English)In: Proceedings of the International Conference on Advanced Manufacturing Engineering and Technologies / [ed] Archenti, Andreas; Maffei, Antonio, Stockholm: KTH Royal Institute of Technology, 2013, p. 293-302Conference paper, Published paper (Refereed)
Abstract [en]

Vibration phenomena are a main consideration during the material removal operation, as it has prominent effects on the product quality, cutting tool life, and productivity of that machining operation. Within the context of machining performance, role of enhanced stiffness and damping on the dynamic behaviour of machining systems such as turning and milling is well established. In this experimental analysis, investigations have been conducted for identifying the natural characteristics and dynamic responses of a milling process with the application of a novel carbon based (CNx) nano-composite damping material. TheCNx material has been applied into the joint interface of a workholding device with adaptive dynamic stiffness. Prior investigations of this material, produced by theplasma enhanced chemical vapor (PECVD) process, showed inherent damping capacity via interfacial frictional losses of its micro-columnar structures. For thisstudy, natural characteristics of the workholding system have been characterized bythe modal impact testing method. Dynamic responses during the machining processhave been measured through the vibration acceleration signals. The ultimate objective of this study is to comprehend the potentiality of CNx coating material forimproving machining process performance by analyzing the frequency response functions and measured vibration signals of the investigated milling process with varying stiffness and damping levels.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2013
Keywords
carbon based nano-composite material
National Category
Production Engineering, Human Work Science and Ergonomics
Research subject
SRA - Production
Identifiers
urn:nbn:se:kth:diva-140737 (URN)978-91-7501-892-8 (ISBN)
Conference
Proceedings of the International Conference on Advanced Manufacturing Engineering and Technologies NEWTECH 2013; Stockholm, Sweden, 27-30 October, 2013
Projects
EU FP7 PoPJIM
Funder
XPRES - Initiative for excellence in production research
Note

QC 20140205

Available from: 2014-01-31 Created: 2014-01-31 Last updated: 2014-02-05Bibliographically approved
Österlind, T., Frangoudis, C. & Archenti, A. (2013). Operational Modal Analysis During Milling Of Workpiece, Fixed On A Stiffness Controllable Joint. Journal of Machine Engineering, 13(2), 69-78
Open this publication in new window or tab >>Operational Modal Analysis During Milling Of Workpiece, Fixed On A Stiffness Controllable Joint
2013 (English)In: Journal of Machine Engineering, ISSN 1895-7595, Vol. 13, no 2, p. 69-78Article in journal (Refereed) Published
Abstract [en]

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 dynamic characteristics 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.

Place, publisher, year, edition, pages
Wroclaw, Poland: Wroclawska Rada Federacji Stowarzyszen Naukowo-Technicznych NOT, 2013
Keywords
machine tool, operational modal analysis, machining stability
National Category
Production Engineering, Human Work Science and Ergonomics
Research subject
SRA - Production
Identifiers
urn:nbn:se:kth:diva-133565 (URN)
Funder
VinnovaXPRES - Initiative for excellence in production research
Note

QC 20140124

Available from: 2013-11-06 Created: 2013-11-06 Last updated: 2017-03-28Bibliographically approved
Mikler, J., Frangoudis, C. & Lindberg, B. (2011). On a Systematic Approach to Development of Maintenance Plans for Production Equipment. Paper presented at XXII Conference on Supervising and Diagnostics of Machining Systems MODEL BASED MANUFACTURING Karpacz 14th – 17th March 2011. Journal of Machine Engineering, 11(1-2), 87-101
Open this publication in new window or tab >>On a Systematic Approach to Development of Maintenance Plans for Production Equipment
2011 (English)In: Journal of Machine Engineering, ISSN 1895-7595, Vol. 11, no 1-2, p. 87-101Article in journal (Refereed) Published
Abstract [en]

Reliability is a collective term covering several abilities of the technical system: to deliver required functions, to uphold quality of products and services, to assure that the safety requirements associated with the system are properly fulfilled with regards both to the users and the environment and finally to uphold the durability of the technical system during its whole life cycle. All this has to be performed at acceptable risks, optimal cost, and correspond to operational needs of the business. Even though there is an advanced, well thought-out concept for this purpose - reliability centred maintenance (RCM) - that correctly applied might result in very good quality maintenance programs, it is not broadly used in the industry due to the vast efforts required for its implementation. An appropriate methodology supporting systematic functional break down of a studied systems, and guidelines how to couple functional failures to failure modes, integrated with RCM, would greatly speed up generating of effective maintenance programs. In this paper we present our research towards development of such a methodology, and show a pilot implementation to analysis of machine tool spindle. The methodology is based on Hubka's theory of design and AFD/TRIZ.

Keywords
Reliability, Maintenance, RCM, TRIZ
National Category
Production Engineering, Human Work Science and Ergonomics
Research subject
SRA - Production
Identifiers
urn:nbn:se:kth:diva-61167 (URN)
Conference
XXII Conference on Supervising and Diagnostics of Machining Systems MODEL BASED MANUFACTURING Karpacz 14th – 17th March 2011
Funder
XPRES - Initiative for excellence in production research
Note

QC 20120119

Available from: 2012-01-16 Created: 2012-01-16 Last updated: 2013-01-22Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0003-0219-1667

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