Size optimization method for controlling the buckling mode shape and critical buckling temperature of composite structures

2021 ◽  
Vol 255 ◽  
pp. 112902
Author(s):  
Hoo Min Lee ◽  
Gil Ho Yoon
2014 ◽  
Vol 490-491 ◽  
pp. 712-718
Author(s):  
Xue Bao Xia ◽  
Yang Xiang ◽  
Shao Wei Wu

Power flow analysis is a method to describe the dynamic behavior of structures by taking not only the amplitude of exciting force and velocity response into account, but also the phase between the two qualities. Shape optimization is an effective method to reduce vibration level. By choosing the vibration power flow as design objective, a shape optimization method of structure is presented. The structure surface is restructured with a series of mode shape superposition. By using genetic algorithm, the weight coefficient of each mode shape is optimized to get the best surface shape with minimum power flow response. Some examples are demonstrated to verify the efficiency and accuracy of the method.


2011 ◽  
Vol 328-330 ◽  
pp. 435-440
Author(s):  
Jun Liao ◽  
Lan Shan ◽  
Yan Feng

The establishment of FCEV finite element model of the subframe is based on Hypermesh platform, and a new subframe structure is designed in accordance with the stiffness and strength analysis on the original subframe in all conditions. High-strength steel materials are used to optimize the design of this new structure, which result in the optimal size. Through the comparative analysis of the strength, stiffness, mode shape and quality on new subframe and the original one, it is verified that the design of the new subframe is reasonable and feasible.


2021 ◽  
pp. 1-15
Author(s):  
Yuqing Zhou ◽  
Tsuyoshi Nomura ◽  
Enpei Zhao ◽  
Kazuhiro Saitou

Abstract Variable-axial fiber-reinforced composites allow for local customization of fiber orientation and thicknesses. Despite their significant potential for performance improvement over the conventional multiaxial composites and metals, they pose challenges in design optimization due to the vastly increased design freedom in material orientations. This paper presents an anisotropic topology optimization method for designing large-scale, 3D variable-axial lightweight composite structures subject to multiple load cases. The computational challenges associated with large-scale 3D anisotropic topology optimization with extremely low volume fraction are addressed by a tensor-based representation of 3D orientation that would avoid the 2π periodicity of angular representations such as Euler angles, and an adaptive meshing scheme, which, in conjunction with PDE regularization of the density variables, refines the mesh where structural members appear and coarsens where there is void. The proposed method is applied to designing a heavy-duty drone frame subject to complex multi-loading conditions. Finally, the manufacturability gaps between the optimized design and the fabrication-ready design for Tailored Fiber Placement (TFP) is discussed, which motivates future work toward a fully-automated design synthesis.


Author(s):  
Zhijun Liu ◽  
Shingo Cho ◽  
Akihiro Takezawa ◽  
Xiaopeng Zhang ◽  
Mitsuru Kitamura

2007 ◽  
Vol 129 (5) ◽  
pp. 533-540 ◽  
Author(s):  
J. Zhang ◽  
G. T. Zheng

Application of viscoelastic materials in vibration and noise attenuation of complicated machines and structures is becoming more and more popular. As a result, analytical and numerical techniques for viscoelastic composite structures have received a great deal of attention among researchers in recent years. Development of a mathematical model that can accurately describe the dynamic behavior of viscoelastic materials is an important topic of the research. This paper investigates the procedure of applying the Biot model to describe the dynamic behavior of viscoelastic materials. As a minioscillator model, the Biot model not only possesses the capability of its counterpart, the GHM (Golla-Hughes-McTavish) model, but also has a simpler form. Furthermore, by removing zero eigenvalues, the Biot model can provide a smaller-scale mathematical model than the GHM model. This procedure of dimension reduction is studied in detail here. An optimization method for determining the parameters of the Biot model is also investigated. With numerical examples, these merits, the computational efficiency, and the accuracy of the Biot model are illustrated and proved.


2012 ◽  
Vol 217-219 ◽  
pp. 179-183
Author(s):  
Wen Guo Zhu ◽  
Zhi Jun Meng ◽  
Jun Huang ◽  
Wei He

An effective optimization method is developed for laminated composite structures using two-level optimization strategy based on Kriging model and genetic algorithm (GA). Firstly, the design of experiment (DOE) technique is used to create sample points and MSC.Nastran is employed to obtain the response (minimum weight subjected to bulking and strength constraints) of each sample point. Based on sample points and the corresponding responses, the Kriging model is formulated. Secondly, GA is performed to obtain the best thickness by optimizing the Kriging model as objective function. Then, the best stacking sequence is obtained basing on lamination parameters using GA. This paper takes a Z shape composite stiffened plate as example to verify the feasibility of the method above. The results illustrate that it can significantly save computational costs and can greatly improve the optimization efficiency.


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