A Structure Analysis Method for Machine Tools Based on Assembly Relationship

2010 ◽  
Vol 29-32 ◽  
pp. 2443-2448
Author(s):  
Dong Fang Hu ◽  
Yan Li ◽  
Jian Dong Shang

Considering the nonlinear relationship of the joint surface between parts in machine tool assembly, a finite element analysis method based on assembly relationship is proposed. By this method, a finite element model is set up. Based on the analysis of experimental data, the result is close to the actual working conditions, which proves that this analysis method based on the machine tool assemble relationship is feasible and reliable

Author(s):  
Anan Zhou ◽  
Xiaopeng Wang ◽  
Tianning Chen

In the finite element analysis (FEA) of machine tools, the study on contact parameters uses the data calculated by theory or identified by experiment directly, which may cause the great distinguish between the results obtained by FEA and by experiment. It is well known that the basic assumption on contact is the contact load of the joint surface stays the same throughout all areas. For the joint surfaces with small areas the loads are well-distributed and unchanged. But for the big joint surfaces the error will be very large with that assumption. A different method was proposed in this paper to calculate the parameters of joint surfaces with big areas. According to the different load conditions, we divided the joint surfaces into different parts and for each part the contact parameters were calculated respectively by the theory we established before. Substituting the parameters into the finite element model the result of FEA can be got. Moreover the methods on how to divide the joint surfaces into parts and how to apply the parameters to FEA of machine tools were also discussed. A dynamic experimental study on contact parameters was carried out. The first 3 natural frequencies and mode shapes of the experiment had a good agreement with the ones of FEA while the error was acceptable. As a result, for the joint surfaces with big areas such as those in machine tools, using the method proposed in this paper, the result of FEA will be more reasonable and the finite element model will be much closer to real one.


2013 ◽  
Vol 281 ◽  
pp. 165-169 ◽  
Author(s):  
Xiang Lei Zhang ◽  
Bin Yao ◽  
Wen Chang Zhao ◽  
Ou Yang Kun ◽  
Bo Shi Yao

Establish the finite element model for high precision grinding machine which takes joint surface into consideration and then carrys out the static and dynamic analysis of the grinder. After the static analysis, modal analysis and harmonic response analysis, the displacement deformation, stress, natural frequency and vibration mode could be found, which also helps find the weak links out. The improvement scheme which aims to increase the stiffness and precision of the whole machine has proposed to efficiently optimize the grinder. And the first natural frequency of the optimized grinder has increased by 68.19%.


2011 ◽  
Vol 117-119 ◽  
pp. 1535-1542 ◽  
Author(s):  
Hua Wei Zhang ◽  
Wei Xia ◽  
Zhi Heng Wu

In this paper, the clamping unit of a two-platen injection molding machine was modeled by Pro/ENGINEER, and was imported to Altair HyperWorks. In HyperMesh module, the finite element model was set up, ANSYS has been used in the finite element analysis of the clamping unit and the deformation and stress results were obtained. Based on the topology optimization of HyperWorks/OptiStruct, recommendations to improve the structure of the clamping mechanism are presented; the results showed that less material was used while its performance was maintained.


2014 ◽  
Vol 555 ◽  
pp. 555-560 ◽  
Author(s):  
Doru Bardac ◽  
Constantin Dogariu

This paper presents a method to investigate the characteristics of a turning high-speed spindle system. The geometric quality of high-precision parts is highly dependent on the performance of the entire machining system,especially by the main spindle behaviour. The machine tool main spindle units is focused on direct driven spindle units for high-speed and high performance cutting. This paper analyzes the static behavior for a turning machine spindle and presents some activities to improve the CAD model for such complex systems. The proposed models take into account the spindle with the detailed bearing system. The analysis was performed during the design activity and was based on Finite Elements Method. Starting from the 3D designed model, using FEM done by means of ANSYS analysis the structure stiffness was evaluated and, by consequence, the influence on the machine tool precision. The aim of this paper is to develop a finite element model of the machine spindle system and to use this method for design optimization. The 3D model was designed using the SolidWorks CAD software. The static analysis was completed by modal, harmonic response and thermal analysis, but their results will be presented in other papers.


2012 ◽  
Vol 557-559 ◽  
pp. 300-303
Author(s):  
Cheng Hong Duan ◽  
Xiang Peng Luo ◽  
Nan Zhang

In this paper, a finite element model of a composite gas cylinder was established by ABAQUS finite element software, with consideration that both heads were helically wound and their wound angle and wound thickness varied with different parallel circle radius. Stress of the composite gas cylinder and PEEQ of its liner under different working conditions after autofrettage treatment were studied, the stress distribution was assessed by the DOT CFFC standard and the effective range of autofrettage treatment was confirmed. This finite element analysis method may be referable to the design and inspection of composite gas cylinders.


2014 ◽  
Vol 580-583 ◽  
pp. 1369-1376
Author(s):  
Bin Shu ◽  
Jian He Peng

The paper aims to solve the serious and regular crack problems in underground garage. ANSYS finite element software is applied to set up the overall finite element model on floor-foundation and foundation coupling beam-foundation soil in underground garage. Combined with engineering field detection, factors influencing underground garage floor like underground water level, soil expansion caused by water content change in expansive soil, soil poisson ratio, foundation settlement are taken into consideration to find out the causes of cracks. The study is expected to provide reference for similar cases in other projects.


2013 ◽  
Vol 712-715 ◽  
pp. 1391-1394
Author(s):  
Zhi Li ◽  
X. S. Zhao ◽  
D. W. Zhang

Modal analysis is one way of studying the dynamic characteristics of the mechanical. In order to study the dynamic characteristics of machine tool,numerical machine model is set up with finite element analysis software,of which validity is verified by experimental modal analysis.The experimental test also provide the boundary conditions, so as to further structure modification and dynamic characteristic design


Author(s):  
Prabhu Raja Venugopal ◽  
M Kalayarasan ◽  
PR Thyla ◽  
PV Mohanram ◽  
Mahendrakumar Nataraj ◽  
...  

Higher damping with higher static stiffness is essential for improving the static and dynamic characteristics of machine tool structures. The structural vibration in conventional machine tools, which are generally made up of cast iron and cast steel, may lead to poor surface finish and the dimensional inaccuracy in the machined products. It leads to the investigation of alternative machine tool structural materials such as concrete, polymer concrete, and epoxy granite. Although epoxy granite has a better damping capacity, its structural stiffness (Young's modulus) is one-third as compared to cast iron. Therefore, the present work represents optimization of the structural design of the vertical machining center column by introducing various designs of steel reinforcement in the epoxy granite structure to improve its static and dynamic characteristics using experimental and numerical approaches. A finite element model of the existing cast iron vertical machining center column has been developed and validated against the experimental data obtained using modal analysis. Furthermore, finite element models for various epoxy granite column designs have been developed and compared with the static and dynamic characteristics of cast iron column. A total of nine design configurations for epoxy granite column with steel reinforcement are evolved and numerical investigations are carried out by finite element analysis. The proposed final configuration with standard steel sections has been modeled using finite element analysis for an equivalent static stiffness and natural frequencies of about 12–20% higher than cast iron structure. Therefore, the proposed finite element model of epoxy-granite-made vertical machining center column can be used as a viable alternative for the existing column in order to achieve higher structural damping, equivalent or higher static stiffness and, easy and environmental-friendly manufacturing process.


Author(s):  
Shanmugam Chinnuraj ◽  
PR Thyla ◽  
S Elango ◽  
Prabhu Raja Venugopal ◽  
PV Mohanram ◽  
...  

Machine tools are used to manufacture components with desired size, shape, and surface finish. The accuracy of machining is influenced by stiffness, structural damping, and long-term dimensional stability of the machine tool structures. Components machined using such machines exhibit more dimensional variations because of the excessive vibration during machining at higher speeds. Compared to conventional materials like cast iron, stone-based polymer composites such as epoxy granite have been found to provide improved damping characteristics, by seven to ten folds, due to which they are being considered for machine tool structures as alternate materials. The stiffness of structures made of epoxy granite can be enhanced by reinforcing with structural steel. The current work highlights the design and analysis of different steel reinforcements in the lathe bed made of the epoxy granite composite to achieve equivalent stiffness to that of cast iron bed for improved static and dynamic performances of the CNC lathe. A finite element model of the existing the cast iron bed was developed to evaluate the static (torsional rigidity) and dynamic characteristics (natural frequency) and the results were validated using the experimental results. Then finite element models of five different steel reinforcement designs of the epoxy granite bed were developed, and their static and dynamic behaviors were compared with the cast iron bed through numerical simulation using finite element analysis. The proposed design (Design-5) of the epoxy granite bed is found to have an improvement in dynamic characteristics by 4–10% with improved stiffness and offers a mass reduction of 22% compared to the cast iron bed, hence it can be used for the manufacture of the CNC lathe bed and other machine tool structures for enhanced performance.


2014 ◽  
Vol 607 ◽  
pp. 286-289
Author(s):  
Hai Fei Qiu ◽  
Song Lin Wu ◽  
Hong Cai Yang

Trough roller is an important component part on belt conveyor, the carrying capacity of the roller is a basis of belt conveyor. The calculation principle and method of material’s cross section area is deduced in the thesis, and mechanical analysis of the trough roller is carried out based on that, in results, the static load of it is calculated. The finite element model of the trough roller is set up by Simulation /Works software, and then the stress and deformation results of it is clear through finite element statics calculation and analysis. Based on this thesis, some valuable basis and reference are offered to trough roller’s strength and stiffness design.


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