Topology Optimization of Compliant Mechanisms Based on Interpolation Meshless Method and Geometric Nonlinearity

2019 ◽  
Author(s):  
Yonghong Zhang ◽  
Zhenfei Zhao ◽  
Yaqing Zhang ◽  
Wenjie Ge
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Topology Optimization ◽  
Galerkin Method ◽  
Meshless Method ◽  
Geometric Nonlinearity ◽  
Compliant Mechanism ◽  
Linear Convergence ◽  
The Finite Element Method ◽  
Element Method

Abstract In order to prevent mesh distortion problem arising in topology optimization of compliant mechanism with massive displacement, a meshless Galerkin method was proposed and studied in this paper. The element-free Galerkin method (EFG) is more accurate than the finite element method, and it does not need grids. However, it is difficult to impose complex boundaries. This paper presents a topology optimization method based on interpolation meshless method, which retains the advantages of the finite element method (FEM) that is easy to impose boundary conditions and high accuracy of the meshless method. At the same time, a method of gradually reducing step is proposed to solve the problem of non-linear convergence caused by low-density points in topology optimization. Numerical example shows that these techniques are valid in topology optimization of compliant mechanism considering the geometric nonlinearity, and simultaneously these techniques can also improve the convergence of nonlinearity.

Natural Frequencies of Rectangular Membrane With Boundary Perturbation

1995 ◽  
Vol 1 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Jamal A. Masad
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Galerkin Method ◽  
Natural Frequency ◽  
Natural Frequencies ◽  
Perturbation Approach ◽  
Boundary Perturbation ◽  
The Finite Element Method ◽  
Analytic Expression ◽  
Element Method

A perturbation approach, coupled with the adjoint concept, is used to derive an analytic expression for the natural frequencies of a nearly rectangular membrane. The method is applied for a rectangular membrane with a semicircle at one of the boundaries. The fundamental natural frequency results for this configuration are presented and compared with results from a finite-element method and results from an approximate Galerkin method. The agreement between the fundamental natural frequencies calculated with the perturbation approach and those calculated with the finite-element method improves as the radius of the semicircle decreases and as the semicircle location becomes more eccentric.

On the Comparison of the Pseudo Rigid Body Model Method and the Finite Element Method for a 3DOF Planar Micro-Motion Stage

2000 ◽  
Author(s):  
J. Zou ◽  
L. G. Watson ◽  
W. J. Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Compliant Mechanism ◽  
The Finite Element Method ◽  
Real Time Control ◽  
Body Model ◽  
Time Control ◽  
Rigid Body Model ◽  
Micro Motion ◽  
Element Method

Abstract This paper discusses one type of commonly used parallel manipulator mechanism for the generation of micro-motion. This mechanism is designed as a compliant mechanism. The design and control of such a compliant mechanism is an important issue. This paper focuses on kinematic issues with consideration of future real-time control of the system. In particular, a constant-Jacobian method to approximate the kinematics, which is based on a pseudo rigid body model of the compliant mechanism, is further validated. This validation is based on the difference between this approximate method and the finite element method to the actual device, for an actuator range of 0–15 μm. The computational time with this approximate method is nearly 50 times less than that with the finite element method. It is expected that this approximation method will be far superior to the finite element method in terms of real-time control.

MODELING OF SPOKE STIFFNESS FOR EXTERNAL FIXATION DEVICES

2020 ◽  
Author(s):  
Aleksandr Bushmanov ◽  
D Mel'nichenko
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
External Fixation ◽  
Geometric Nonlinearity ◽  
Transverse Force ◽  
The Finite Element Method ◽  
Fixation Devices ◽  
Preliminary Tension ◽  
Element Method

A nonlinear calculation of the stiffness of the spokes of external fixation devices in traumatology is proposed. Taking into account the geometric nonlinearity of the spoke, the finite element method is used in the calculations of stiffness and stresses arising in the spoke fasteners. Under the action of the transverse force and its preliminary tension, deflections of the spoke and stresses in the attachment points are determined.

scholarly journals Revised Level Set-Based Method for Topology Optimization and Its Applications in Bridge Construction

2017 ◽  
Vol 11 (1) ◽  
pp. 153-166
Author(s):  
Jing Wu ◽  
Li Wu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Topology Optimization ◽  
Level Set ◽  
The Finite Element Method ◽  
Bridge Design ◽  
Bridge Construction ◽  
Level Set Function ◽  
Set Function ◽  
Element Method

To cure imperfections such as low accuracy and the lack of ability to nucleate hole in the conventional level set-based topology optimization method, a novel method using a trapezoidal method with discrete design variables is proposed. The proposed method can simultaneously accomplish topology and shape optimization. The finite element method is employed to obtain element properties and provide data for calculating design and topological sensitivities. With the aim of performing the finite element method on a non-conforming mesh, a relation between the level set function and the element densities field has to be clearly defined. The element densities field is obtained by averaging the Heaviside function values. The Lagrange multiplier method is exploited to fulfill the volume constraint. Based on topological and design sensitivity and the trapezoidal method, the Hamilton-Jacobi partial differential equation is updated recursively to find the optimal layout. In order to stabilize the iterations and improve the efficiency of the algorithm, re-initiation of the level set function is necessary. Then, the detailed process of a cantilever design is illustrated. To demonstrate the applications of the proposed method in bridge construction, two numerical examples of a pylon bridge design are introduced. It is shown that the results match practical designs very well, and the proposed method is a helpful tool in bridge design.

The Optimization and Improvement of Truck Brake Caliper Bracket Based on the Finite Element Method

2014 ◽  
Vol 889-890 ◽  
pp. 86-91
Author(s):  
Ming Xing Lei ◽  
Qin Cao ◽  
Yan Wang ◽  
Peng Fei Xia
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Topology Optimization ◽  
Static Strength ◽  
Front Axle ◽  
The Finite Element Method ◽  
Road Test ◽  
Working Principle ◽  
Element Method

The brake caliper bracket (BCB) of the truck front axle would crack when a certain truck is running in 20000 kilometers road test. In view of the above phenomenon, this paper will use Altair HyperWorks to analyze the static strength of the BCB according to its working principle and load cases. The topology optimization will be done based on the reason found out before. Form the result of the topology optimization, the modified design for the BCB is carried out. Finally, an experiment result is given to check it is correct.

Simulation of tuning graphene plasmonic behaviors by ferroelectric domains for self-driven infrared photodetector applications

Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20868-20875 ◽  
Author(s):  
Junxiong Guo ◽  
Yu Liu ◽  
Yuan Lin ◽  
Yu Tian ◽  
Jinxing Zhang ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Interfacial Effect ◽  
Infrared Photodetector ◽  
The Finite Element Method ◽  
Ferroelectric Domains ◽  
Element Method

We propose a graphene plasmonic infrared photodetector tuned by ferroelectric domains and investigate the interfacial effect using the finite element method.

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