Finite Element Analysis and Multi-Objective Optimization of the Precision Horizontal Machining Center Bed

2014 ◽  
Vol 889-890 ◽  
pp. 130-134
Author(s):  
Xue Yan Li ◽  
Wen Tie Niu ◽  
Jun Qiang Wang ◽  
Ling Jun Xue

In order to improve dynamic and static performance of the precision horizontal machining center, the method of multi-objective optimization based on the response surface model was applied for optimizing design of the bed structure. The design variables were the layout parameters of the rib plates. Sample points were obtained by the Box-Behnken design experiment, and responses of sample points were analyzed by SAMCEF. The maximum deformation of guide rails and the low-order natural frequency were extracted to fit the response surface model by least square method. The layout parameters of the rib plates were optimized through the application of multi-objective genetic algorithms. Then, relationship between the lightening holes and the performance were analyzed to determine the suitable diameter. The results verify the validity of the optimization method, and the paper provides methodological guidance for optimization of machine tool structural parts.

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 403
Author(s):  
Shuang Wu ◽  
Jiefang Xing ◽  
Ling Dong ◽  
Honjuan Zhu

In order to improve the structural stiffness of the gravure cell structure in the solid printing process and realize a lightweight design, a multi-objective optimization design method was proposed to optimize the parameters of the direct laser engraving of the cell structure. In this paper, based on the characteristics of the cell structure and the analysis of the contact force, the ANSYS parametric design language (APDL) was used to conduct a finite element analysis on the microstructure of the regular hexagonal cell. We found that there is a certain optimization space. Then, a response surface (RSM) method optimization model, using a central composite design (CCD), was established to obtain, and then analyze, the sensitivity of each design variable to the objective functions. Finally, a multi-objective genetic algorithm (MOGA) was used to solve the model. The optimization results show that the maximum deformation was reduced by 44.4%, and the total volume was reduced by 46.3%. By comparing with the model before optimization, the rationality and effectiveness of this method were verified. This shows that the method can be effectively applied to the design optimization of gravure cell microstructure, and it provides theoretical support for new cell design.


Author(s):  
Jianghai Hui ◽  
Min Gao ◽  
Xinpeng Li

Buffer structure is a traditional measure to improve the ammunition's performance of withstanding impact loadings during launch process. On that basis, this paper proposes a parametric optimization for the gasket, which is served as buffer structure in spin microgenerator's rotating rack used in trajectory correction fuze to effectively reduce the stress of bearings used in the rack. It is a finite element dynamic simulation based on rack-projectile-barrel coupling to acquire variation of the bearings' stress. A rack-projectile-barrel coupling model is built and the simulation pre-process is described. At first, the parametric analysis for the gasket is conducted. The effect of the gasket's axial thickness and elastic modulus on the bearings' stress is studied, and the results show that singly changing one of the two gasket's parameters cannot effectively reduce the two-ball bearings' stress. Then, based on the two gasket's parameters, the design of experiment method is applied with 25 sample points established. A kind of approximation, response surface model is created and its fitting accuracy is verified. Single-objective and multi-objective optimization are conducted based on the response surface model, respectively. And the multi-objective optimization for the gasket can successfully reduce the two bearings' stress to the value below the bearing material's yield strength. In addition, to check the optimization's effectiveness, an experiment is carried out and the results indicate that the gasket whose axial thickness and elastic modulus have been optimized can effectively improve the rotating rack's performance of withstanding impact loadings.


2012 ◽  
Vol 184-185 ◽  
pp. 565-569 ◽  
Author(s):  
Peng Xing Yi ◽  
Li Jian Dong ◽  
Yuan Xin Chen

In order to improve the reliability of a planet carrier, a simulation method based on multi-objective design optimization was developed in this paper. The objective of the method was to reduce the stress concentration, the deformation, and the quality of the planet carrier by optimizing the structure dimension. A parametric finite element model, which enables a good understanding of how the parameters affect the reliability of planet carrier, was established and simulated by ANSYS-WORKBENCH. The efficiency of the design optimization was improved by using a polynomials response surface to approximate the results of finite element analysis and a screening algorithm to determine the direction of optimization. Furthermore, the multi-objective optimization was capable of finding the global minimum results in the use of the minimum principle on the response surface. Computer simulation was carried out to verify the validity of the presented optimization method, by which the quality and the stability of the planet carrier were significantly reduced and improved, respectively. The methodology described in this paper can be effectively used to improve the reliability of planet carrier.


Author(s):  
K. Sinha ◽  
A. Dasgupta ◽  
J. Caers

This paper investigates the role of gold-to-gold interfacial metallurgical bonding on the bond strength of adhesively bonded flip-chip interconnects in microelectronic assemblies. [44] dealt with experimental investigation of the effect of bonding parameters on Au-Au interfacial bond strength. One of the major conclusions in [44] was that interfacial creep deformation closely correlated with the measured evolution of bond strength over time. This study presents a viscoplastic finite element analysis to capture the physical creep mechanisms that drive the development of this strength, so that the effect of the system architecture and bonding parameters can be effectively quantified. Based on the studies in literature [42, 43], the strength is assumed to depend on the area of the contact “a-spots,” which are defined here as the area over which the interfaces come into intimate, atomistically flat contact. The most important inputs to the finite element model consist of (i) interfacial geometry (with special emphasis on the surface roughness topology); (ii) viscoplastic mechanical properties of gold; and (iii) bonding parameters (force, temperature and time). The viscoplastic constitutive properties for gold are obtained partly from experiments conducted in this study and partly from the existing literature. The model inputs are parametrically varied in a systematic way within the design space, to obtain the variability expected in the bond strength. The simulation results are captured in a response surface model that can predict bond strength for a given set of fabrication conditions. The response surface model thus serves as a prediction tool critical for optimizing the interconnect strength and the durability of adhesively bonded flip chip assemblies.


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