scholarly journals Topology Optimization of Hard-Coating Thin Plate for Maximizing Modal Loss Factors

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 774
Author(s):  
Haitao Luo ◽  
Rong Chen ◽  
Siwei Guo ◽  
Jia Fu
Keyword(s):  
Topology Optimization ◽  
Objective Function ◽  
Composite Plates ◽  
Optimization Method ◽  
Hard Coating ◽  
Design Variables ◽  
Coating Composite ◽  
Damping Materials ◽  
Topology Optimization Method ◽  
Loss Factors

At present, hard coating structures are widely studied as a new passive damping method. Generally, the hard coating material is completely covered on the surface of the thin-walled structure, but the local coverage cannot only achieve better vibration reduction effect, but also save the material and processing costs. In this paper, a topology optimization method for hard coated composite plates is proposed to maximize the modal loss factors. The finite element dynamic model of hard coating composite plate is established. The topology optimization model is established with the energy ratio of hard coating layer to base layer as the objective function and the amount of damping material as the constraint condition. The sensitivity expression of the objective function to the design variables is derived, and the iteration of the design variables is realized by the Method of Moving Asymptote (MMA). Several numerical examples are provided to demonstrate that this method can obtain the optimal layout of damping materials for hard coating composite plates. The results show that the damping materials are mainly distributed in the area where the stored modal strain energy is large, which is consistent with the traditional design method. Finally, based on the numerical results, the experimental study of local hard coating composites plate is carried out. The results show that the topology optimization method can significantly reduce the frequency response amplitude while reducing the amount of damping materials, which shows the feasibility and effectiveness of the method.

STUDY ON MODAL TOPOLOGY OPTIMIZATION METHOD OF CONTINUUM STRUCTURE BASED ON EFG METHOD

2012 ◽  
Vol 09 (01) ◽  
pp. 1240005 ◽  
Author(s):  
SHUGUANG GONG ◽  
MIN CHEN ◽  
JIANPING ZHANG ◽  
RONG HE
Keyword(s):  
Topology Optimization ◽  
Optimization Method ◽  
Optimality Criteria ◽  
Differential Method ◽  
Gauss Point ◽  
Design Variables ◽  
Continuum Structure ◽  
Nodal Density ◽  
Element Free ◽  
Topology Optimization Method

The modal topology optimization method of continuum structure based on element-free Galerkin (EFG) method is presented by integrating solid isotropic material with penalization (SIMP) method with the optimality criteria method, and the penalty method is used to impose essential boundary conditions. The density of Gauss point and nodal density are selected as the design variables respectively, and the maximum of the first-order natural frequency is specified as the objective function. The sensitivity analysis algorithm is derived by using direct differential method. The examples are finished by selecting the two types of design variables respectively. The results obtained show that the checkerboard phenomenon does not appear when nodal density is selected as the design variable, and also verify that topology optimization method presented is feasible.

Application of a Ground Beam-Joint Topology Optimization Method for Multi-Piece Frame Structure Design

2008 ◽  
Vol 130 (8) ◽  
Author(s):  
Myung-Jin Kim ◽  
Gang-Won Jang ◽  
Yoon Young Kim
Keyword(s):  
Topology Optimization ◽  
Optimization Technique ◽  
Joint Stiffness ◽  
Optimization Method ◽  
Structure Design ◽  
Frame Structure ◽  
Optimal Layout ◽  
Design Variables ◽  
Discrete Values ◽  
Topology Optimization Method

When a multipiece frame structure is designed, not only its topological layout but also assembly locations should be determined. This paper presents a compliance-minimizing topology optimization technique to determine an optimal layout configuration and to suggest candidate assembly locations. The technique employs a ground beam-joint model and places candidate assembly joints where the values of joint stiffness are relatively small. The zero-length joint elements have varying stiffness controlled by real-valued design variables. Because joint stiffness values at the converged state can be utilized to select candidate assembly locations along with their strengths, the technique is extremely useful in multipiece frame structure design. Because structural properties of ground beams can have only discrete values or remain unchanged for optimization process, no poststructural modification is required in an actual manufacturing step.

Design Sensitivity Analysis and Topology Optimization Method Applied to Stiffener Layout in Hull Structures

2006 ◽  
Vol 50 (03) ◽  
pp. 222-230
Author(s):  
Yoondo Ha ◽  
Woojong Kim ◽  
Seonho Cho
Keyword(s):  
Sensitivity Analysis ◽  
Topology Optimization ◽  
Numerical Models ◽  
Optimization Method ◽  
Design Sensitivity ◽  
Design Sensitivity Analysis ◽  
Von Mises Stress ◽  
Mindlin Plate ◽  
Design Variables ◽  
Topology Optimization Method

A continuum-based design sensitivity analysis (DSA) method is developed for threedimensional Mindlin plate structures. The first-order variations of energy form, load form, and structural responses with respect to nonshape design variables are derived. An adjoint variable method is employed because of its computational efficiency, especially with respect to problems where there are many design variables but only a few performance measures. The developed DSA method is utilized with the topology optimization method by using a density approach, which yields an optimal structural layout for the required structural performances. For the numerical implementation, a finite element method, the developed DSA method, and a gradient-based topology optimization method are integrated into a unified and automated framework. The developed topology optimization method is applied to the numerical models of stringer and cargo hold to find the optimal layout of stiffeners. Comparing the existing and optimal designs, significant improvements in the displacement and Von Mises stress distributions are observed. The results show that the topology optimization method can be used as a useful tool for determining a suitable layout of stiffeners in the early stage of hull structural design.

2112 A topology optimization method using the signed distance function as the design variables

2009 ◽  
Vol 2009.22 (0) ◽  
pp. 404-405
Author(s):  
Shintaro Yamasaki ◽  
Tsuyoshi Nomura ◽  
Atsushi Kawamoto ◽  
Kazuo Sato ◽  
Kazuhiro Izui ◽  
...  
Keyword(s):  
Topology Optimization ◽  
Distance Function ◽  
Optimization Method ◽  
Signed Distance Function ◽  
Signed Distance ◽  
Design Variables ◽  
Topology Optimization Method

Structural Topology Optimization Using Frame Elements Based on the Complementary Strain Energy Concept for Eigen-Frequency Maximization

2005 ◽  
Author(s):  
Akihiro Takezawa ◽  
Shinji Nishiwaki ◽  
Kazuhiro Izui ◽  
Masataka Yoshimura
Keyword(s):  
Topology Optimization ◽  
Cross Sections ◽  
Strain Energy ◽  
Optimization Procedure ◽  
Optimization Method ◽  
Structural Topology ◽  
Energy Concept ◽  
Conceptual Design Phase ◽  
Complementary Strain ◽  
Topology Optimization Method

This paper discuses a new topology optimization method using frame elements for the design of mechanical structures at the conceptual design phase. The optimal configurations are determined by maximizing multiple eigen-frequencies in order to obtain the most stable structures for dynamic problems. The optimization problem is formulated using frame elements having ellipsoidal cross-sections, as the simplest case. Construction of the optimization procedure is based on CONLIN and the complementary strain energy concept. Finally, several examples are presented to confirm that the proposed method is useful for the topology optimization method discussed here.

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