Optimal Design of Bi- and Multi-Stable Compliant Cellular Structures

2018 ◽  
Author(s):  
Quantian Luo ◽  
Liyong Tong
Keyword(s):  
Optimal Design ◽  
Virtual Work ◽  
Reaction Force ◽  
Nonlinear Finite Element ◽  
Cellular Structures ◽  
Stress And Strain ◽  
Principle Of Virtual Work ◽  
Stable States ◽  
Threshold Method ◽  
Element Analysis

This paper presents optimal design for nonlinear compliant cellular structures with bi- and multi-stable states via topology optimization. Based on the principle of virtual work, formulations for displacements and forces are derived and expressed in terms of stress and strain in all load steps in nonlinear finite element analysis. Optimization for compliant structures with bi-stable states is then formulated as: 1) to maximize the displacement under specified force larger than its critical one; and 2) to minimize the reaction force for the prescribed displacement larger than its critical one. Algorithms are developed using the present formulations and the moving iso-surface threshold method. Optimal design for a unit cell with bi-stable states is studied first, and then designs of multi-stable compliant cellular structures are discussed.

Nonlinear Finite Element Analysis for Galloping of Iced Quad-Bundled Conductor

2013 ◽  
Vol 470 ◽  
pp. 232-235
Author(s):  
Li Qin ◽  
Ya Nan Li ◽  
Xiao Guang Wei
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Degrees Of Freedom ◽  
Virtual Work ◽  
Nonlinear Finite Element Analysis ◽  
Aerodynamic Characteristics ◽  
Nonlinear Finite Element ◽  
Principle Of Virtual Work ◽  
Element Analysis ◽  
Beam Elements

Based on the differences aerodynamic characteristics between each sub-conductor of iced bundled conductors, a two-node cable element with three translational and one torsional degrees of freedom at each node is utilized to imitate the bundled conductor and the two-node space beam elements are used to simulated the spacers. Established nonlinear finite element equations of bundled conductors based on the principle of virtual work and solved these equations using Newmark-β method. Numerical example was employed to demonstrate the reliable and efficient of the presented method and program.

Finite Element Analysis of Motor Box for EBZ160 Horizontal Roadheader

2015 ◽  
Vol 1090 ◽  
pp. 233-237
Author(s):  
Ji Jun Miao ◽  
Ri Sheng Long
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optimal Design ◽  
Safety Factor ◽  
Stress And Strain ◽  
Element Analysis

In order to solve the cracking and poor reliability problems of motor box of Horizontal Roadheader, the static structural FEA (Finite Element Analysis) of cutting arm & motor box of the EBH160 Horizontal Roadheader was conducted, and the stress and strain contours of FEA were obtained. By comparing the calculated results, the safety factor of cutting arm & motor box was 1.36, which provides a reference for the optimal design of cutting arm & motor box.

Theoretical and FEM Research on Inelastic Displacement of Assembled Truss Bridge with Cable Reinforcement

2012 ◽  
Vol 178-181 ◽  
pp. 2038-2042
Author(s):  
Yin Zhi Zhou ◽  
Ke Bin Jiang ◽  
Yong Ding ◽  
Jian Kui Yang
Keyword(s):  
Finite Element ◽  
Virtual Work ◽  
The Self ◽  
Principle Of Virtual Work ◽  
Element Analysis ◽  
Inelastic Displacement ◽  
Prestressing Force ◽  
Truss Bridge ◽  
Theoretical Results

This paper presents theoretical and finite element investigations on inelastic displacement of assembled truss bridge with cable reinforcement (hereinafter referred to as ATCR). A method based on the Principle of virtual work for the determination of the inelastic displacement of ATCR is proposed. Finite element analysis was conducted on the specimen models using the ANSYS program, in order to obtain the inelastic displacement of ATCR and to compare with theoretical results. This study focuses on Bailey bridge under the self-weight load and prestressing force on cable. This paper analyzes various specimens to obtain inelastic displacement in different cases. The approximations of a relation between the inelastic displacement and prestressing force on cable are found. It can be seen that the method in this paper can both calculate the inelastic displacement of traditional truss and prestressed truss (ATCR). Based on both the theoretical and the finite element results, it can be concluded that the relation curve between inelastic displacement and prestressing force is stepwise.

Using Simulation to Help Specify Design Parameters for Vacuum-Assisted Needle Biopsy Systems

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Xuelian Gu ◽  
Fangqiu Hu ◽  
Chi-Lun Lin ◽  
Arthur Erdman ◽  
Licheng Lu
Keyword(s):  
Needle Biopsy ◽  
Reaction Force ◽  
Peak Stress ◽  
Axial Direction ◽  
Tissue Reaction ◽  
Design Parameters ◽  
Stress And Strain ◽  
Medical Procedure ◽  
Element Analysis ◽  
The Finite Element Analysis

Needle biopsy is a routine medical procedure for examining tissue or biofluids for the presence of disease using standard methods of pathology. The finite element analysis (FEA) methodology can provide guidance for optimizing the geometric parameters. The needle biopsy is simulated and analyzed while varying the needle angle, the aperture size and the slice-push ratio k. The results indicate that tissue reaction force in the axial direction of needle gradually decreases, and the stress and strain are more concentrated at the tip of needle with the increases of tip angle; the tissue reaction force decreases, and the torque increases while the slice-push ratio increases; and higher slice–push ratio can increase the peak stress concentration on the cutting edge and deformation of tissue; in the process of core needle cutting, increasing slice–push ratio can reduce the tissue reaction force significantly. While the aperture on distal wall of outer cannula becomes wider, the tissue reaction force increases significantly, and the cutting process will be more unstable. The results have the potential to provide important insight for improving the needle biopsy design process.

scholarly journals Finite Element Analysis on Knee Joint with Leg Length Inequality

2018 ◽  
Vol 7 (4.30) ◽  
pp. 359
Author(s):  
N. F. Othman ◽  
M. N. A. Suhaimi ◽  
K. S. Basaruddin ◽  
M. H. Mat Som ◽  
W. M. R. Rusli
Keyword(s):  
Knee Joint ◽  
Reaction Force ◽  
Equivalent Stress ◽  
Static Condition ◽  
Von Mises Stress ◽  
Stress And Strain ◽  
Leg Length ◽  
Joint Reaction Force ◽  
Element Analysis ◽  
Joint Reaction

This study aims to investigate the effect of leg length discrepancy (LLD) on the joint reaction stress and strain of femur particularly in the knee joint. The knee joint model was developed using CATIA and imported into ANSYS to simulate the LLD case based on the value of the joint reaction force from the previous experimental study. The analysis was done under a linear static condition. The knee components were divided on three; bone (femur and tibia), cartilage (femoral cartilage and tibial plateau cartilage) and menisci. The effect of LLD on the knee joint was determined by observing the contour of equivalent stress and strain distribution on the knee joint components and the maximum equivalent von-Mises stress and strain. The result shows a higher value of stress and strain was found on the short leg compared to the long leg due to the LLD. The pattern of overall results shows that the magnitude of stress-strain is proportional to the level of increments in LLD. Since the short leg demonstrate the greater in stress and strain value, it is prone to experience failure in the future such as wear in cartilage.

On the Mechanical Behavior of the Orthotropic Cord-Rubber Composite

1976 ◽  
Vol 4 (4) ◽  
pp. 219-232 ◽  
Author(s):  
Ö. Pósfalvi
Keyword(s):  
Mechanical Behavior ◽  
Uniaxial Tension ◽  
Elastic Properties ◽  
Large Deformations ◽  
Virtual Work ◽  
Poisson's Ratio ◽  
Principle Of Virtual Work ◽  
Effective Elastic Properties ◽  
Rubber Composite ◽  
Mooney Equation

Abstract The effective elastic properties of the cord-rubber composite are deduced from the principle of virtual work. Such a composite must be compliant in the noncord directions and therefore undergo large deformations. The Rivlin-Mooney equation is used to derive the effective Poisson's ratio and Young's modulus of the composite and as a basis for their measurement in uniaxial tension.

scholarly journals Discrete element model for general polyhedra

2021 ◽  
Author(s):  
Alfredo Gay Neto ◽  
Peter Wriggers
Keyword(s):  
Frictional Contact ◽  
Virtual Work ◽  
Particle Surface ◽  
Element Model ◽  
Discrete Element ◽  
Discrete Element Model ◽  
Principle Of Virtual Work ◽  
Dynamics Model ◽  
Railway Ballast ◽  
Multibody Dynamics Model

AbstractWe present a version of the Discrete Element Method considering the particles as rigid polyhedra. The Principle of Virtual Work is employed as basis for a multibody dynamics model. Each particle surface is split into sub-regions, which are tracked for contact with other sub-regions of neighboring particles. Contact interactions are modeled pointwise, considering vertex-face, edge-edge, vertex-edge and vertex-vertex interactions. General polyhedra with triangular faces are considered as particles, permitting multiple pointwise interactions which are automatically detected along the model evolution. We propose a combined interface law composed of a penalty and a barrier approach, to fulfill the contact constraints. Numerical examples demonstrate that the model can handle normal and frictional contact effects in a robust manner. These include simulations of convex and non-convex particles, showing the potential of applicability to materials with complex shaped particles such as sand and railway ballast.

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