scholarly journals Influences of Collared Ribs and Core-Holes on the Static Stiffness of Cylindrical Column : Study on the C.A.D for Machine Tool Structures, Part 1

1975 ◽  
Vol 18 (121) ◽  
pp. 744-753 ◽  
Author(s):  
Mitsuyoshi KOIZUMI ◽  
Yoshimi ITO ◽  
Masami MASUKO
Keyword(s):  
Machine Tool ◽  
Static Stiffness ◽  
Column Study ◽  
Cylindrical Column ◽  
Machine Tool Structures

Application of Sandwich-Based Designs on Main Structural Parts of Machine Tools

2011 ◽  
Author(s):  
Jan Smoli´k ◽  
Viktor Kuli´sˇek ◽  
Miroslav Janota
Keyword(s):  
Machine Tool ◽  
Machine Tools ◽  
High Speed ◽  
High Performance ◽  
Transportation Industry ◽  
Static Stiffness ◽  
Modal Damping ◽  
Machine Tool Structures ◽  
Structural Parts

New, higher and challenging properties of new high-speed machines and high-performance machines bring up many questions connected to the design and properties of the main machine tool structures. Parameters like static stiffness, eigenfrequencies, modal damping and mass of parts may be identified as very important, and all these properties need to be improved. The most important material properties in the field of machine tools are presented in this paper. A case study based on a modification of a real horizontal machining centre is introduced. The modification consists in using a sandwich design concept in the main structural machine tool part. The sandwich concept, widely known and used in the aerospace industry and, more generally, the transportation industry, is not commonly used in machine tool design. A significant reduction of mass has been achieved by manufacturing a hybrid column with aluminum foam cores, while static stiffness has not been affected.

Design and analysis of epoxy granite vertical machining centre base for improved static and dynamic characteristics

2019 ◽  
Vol 234 (3) ◽  
pp. 481-495 ◽  
Author(s):  
Prabhu Raja Venugopal ◽  
P Dhanabal ◽  
PR Thyla ◽  
S Mohanraj ◽  
Mahendrakumar Nataraj ◽  
...  
Keyword(s):  
Cast Iron ◽  
Machine Tool ◽  
Dynamic Characteristics ◽  
Element Model ◽  
Numerical Approach ◽  
Structural Vibration ◽  
Polymer Concrete ◽  
Static Stiffness ◽  
Static And Dynamic Characteristics ◽  
Machine Tool Structures

The structural vibration in conventional machine tools which are generally made of cast iron may lead to poor surface finish of the machined components. This has led to the investigations on alternative materials for machine tool structures such as concrete, polymer concrete and epoxy granite which have higher damping properties but lesser Young's modulus. However, higher static stiffness with higher damping is essential for improving the static and dynamic characteristics of machine tool structures. Hence, this work focuses on replacing the vertical machining centre base made of cast iron with steel reinforced epoxy granite to improve the structural static stiffness. A finite element model of the above base is developed and validated against the experimental data obtained using modal analysis. The validated numerical approach is applied for investigating the seven progressive design configurations of base reinforced with steel. It is found that the epoxy granite base of Design configuration-7 with L-channels has significantly reduced the deformation by 56 and 36% considering milling and drilling operations, respectively, in comparison to cast iron base. Further, the natural frequencies of the above configuration are higher in all the modes (by more than 50%) under consideration than those of the existing cast iron structure. Therefore, the proposed configuration of base is a viable alternative for the existing base in order to achieve higher structural damping. The novelty of the present work is the design of epoxy granite vertical machining centre base using steel reinforcements to improve structural rigidity with ease of manufacturing.

Exakte posenabhängige Strukurmodelle*/Accurate virtual machine tool structures - Online-identification of the general model of a lightweight machine tool structure with pose-dependent dynamic behavior

2017 ◽  
Vol 107 (05) ◽  
pp. 323-328
Author(s):  
S. Apprich ◽  
F. Wulle ◽  
A. Prof. Pott ◽  
A. Prof. Verl
Keyword(s):  
Machine Tool ◽  
Least Squares ◽  
Dynamic Behavior ◽  
Natural Frequencies ◽  
Recursive Least Squares ◽  
Machine Model ◽  
Online Identification ◽  
Working Space ◽  
Machine Tool Structure ◽  
Machine Tool Structures

Serielle Werkzeugmaschinenstrukturen weisen ein posenabhängiges, dynamisches Verhalten auf, wobei die Eigenfrequenzen um mehrere Hertz im Arbeitsraum variieren können. Die genaue Kenntnis dieses Verhaltens gestattet eine verbesserte Regelung der Strukturen. Ein generelles parametrisches Maschinenmodell, dessen Parameter online durch einen Recursive-Least-Squares-Algorithmus an das reale Maschinenverhalten angepasst werden, stellt Informationen über dieses Maschinenverhalten bereit.   Serial machine tool structures feature a pose-dependent dynamic behavior with natural frequencies varying by serveral hertz within the working space. The accurate knowledge of this behavior allows an improved control of the structures. A general parametric machine model, whose parameters are adapted online to the actual machine tool behavior by a Recursive Least Squares algorithm, provides information about the pose-dependent dynamic behavior.

Modal Analysis of Machine Tool Structures Based on Experimental Data

1983 ◽  
Vol 105 (4) ◽  
pp. 282-287 ◽  
Author(s):  
K. F. Eman ◽  
K. J. Kim
Keyword(s):  
Transfer Function ◽  
Machine Tool ◽  
Modal Analysis ◽  
Moving Average ◽  
Parametric Representation ◽  
Modeling Procedure ◽  
Fitting Procedure ◽  
Machine Tool Structures ◽  
Computer Based ◽  
Three Degree Of Freedom

The basic problem in modal analysis of machine tool structures is the extraction of modal parameters from the measured transfer function data. Conventionally this task is performed in two steps. The transfer function is determined using a Digital Fourier Analyzer followed by a suitable curve fitting procedure. In order to avoid the inherent problems associated with these procedures a new approach for modal analysis is proposed in this paper. Anticipating the stochastic nature of the systems excitation and response Modified Autoregressive Moving Average Vector models (MARMAV) are proposed. The modeling procedure yields a parametric representation of the structural behavior allowing the extraction of the modal information in one step, directly, rather than in two as in the conventional approaches. The mathematical foundation for the approach is given along with its application to a simulated three-degree-of-freedom system and a knee type milling machine. The newly proposed procedure is commensurate to the existing ones in light of the computational efforts involved; however, it eliminates the subjective judgment of the analyst since the modeling procedure is based on rigorous statistical adequacy checks. Finally, the proposed approach is amenable for implementation in a computer-based machine tool structural dynamics analyzer.

Evaluation of Advanced Cementitious Composites for Machine-Tool Structures

CIRP Annals ◽  
1988 ◽  
Vol 37 (1) ◽  
pp. 373-376 ◽  
Author(s):  
M. Rahman ◽  
M.A. Mansur ◽  
K.H. Chua
Keyword(s):  
Machine Tool ◽  
Cementitious Composites ◽  
Machine Tool Structures
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