Finite-element analysis of time-dependent large-deformation problems

Author(s):  
Manoj B. Chopra ◽  
Gary F. Dargush
Author(s):  
Ashok K. Kancharala ◽  
Eric Freeman ◽  
Michael K. Philen

Biologically inspired droplet interface bilayers have found applications in the development of hair cell sensors and other mechanotransduction applications. In this research, the flexoelectric capability of the droplet bilayers under external excitation is explored for energy harvesting. Traditionally, membrane capacitance models are being used for inferring the magnitude of the membrane deflection which do not account for the relation between the applied force or deflection and the deflection of the interfacial membrane and time dependent variations. In this work, the dynamic behavior of the droplets under external excitation has been modeled using nonlinear finite element analysis. A flexoelectric model including mechanical, electrical, and chemical sensitivities has been developed and coupled with the calculated bilayer deformations to predict the mechanotransductive response of the droplets under excitation. Using the developed framework, the possibilities of energy harvesting for different droplet configurations have been investigated and reported.


2014 ◽  
Vol 970 ◽  
pp. 177-184 ◽  
Author(s):  
Wen Chiet Cheong ◽  
Heng Keong Kam ◽  
Chan Chin Wang ◽  
Ying Pio Lim

A computational technique of rigid-plastic finite element method by using the Eulerian meshing method was developed to deal with large deformation problem in metal forming by replacing the conventional way of applying complicated remeshing schemes when using the Lagrange’s elements. During metal forming process, a workpiece normally undergoes large deformation and causes severe distortion of elements in finite element analysis. The distorted element may lead to instability in numerical calculation and divergence of non-linear solution in finite element analysis. With Eulerian elements, the initial elements are generated to fix into a specified analytical region with particles implanted as markers to form the body of a workpiece. The particles are allowed to flow between the elements after each deformation step to show the deforming pattern of material. Four types of cold forging and sheet metal clinching were conducted to investigate the effectiveness of the presented method. The proposed method is found to be effective by comparing the results on dimension of the final product, material flow behaviour and punch load versus stroke obtained from simulation and experiment.


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