Voronoi Cell Finite Element Model for Thermoelastoplastic Deformation in Random Heterogeneous Media

1994 ◽  
Vol 47 (1S) ◽  
pp. S207-S220 ◽  
Author(s):  
Suresh Moorthy ◽  
Somnath Ghosh ◽  
Yunshan Liu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Heterogeneous Media ◽  
Voronoi Cell ◽  
Element Model ◽  
Second Phase ◽  
Element Mesh ◽  
Model Composite ◽  
Elasto Plasticity ◽  
Dirichlet Tessellation

A finite element model has been developed for analysis of heterogeneous media, in which second phase inclusions are arbitrarily dispersed within a matrix. A mesh generator based on Dirichlet tessellation, discretizes the heterogeneous domain, accounting for the arbitrariness in location, shape and size of the second phase. This results in a network of convex “Voronoi” polygons which form the elements in a finite element mesh. An assumed stress hybrid formulation has been implemented for accommodating arbitrary multi-sided elements in the finite element model. Composite element formulations have been developed to incorporate the effect of second phase within each element. Formulations have been developed for thermo-elasticity, micropolar elasticity and elasto-plasticity.

The Vibration Analysis of Bone Conduction for Bone-Anchored Hearing Aids: In Vivo Human Temporal Bone

2011 ◽  
Vol 145 ◽  
pp. 93-98
Author(s):  
Jen Fang Yu ◽  
Zi Xiang Wei ◽  
Chin Kuo Chen ◽  
Ching I Chen
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Temporal Bone ◽  
Hearing Aids ◽  
Bone Conduction ◽  
Element Model ◽  
Second Phase ◽  
Center Line ◽  
The Finite Element Model

This study constructed a 3D finite element model of temporal bone non-invasively, based on the computed tomography scan image of anin vivotemporal bone. To observe the geometry and measurements of the temporal bone, the finite element model was built using ANSYS®. The finite element model involved two phases. The first phase entailed discussing the natural vibration frequencies and vibration mode of the temporal bone. The second phase involved investigating the harmonic response. The base center and center line were established in the external auditory meatus and the 0 degree direction, respectively. The amplitude force was applied along the center line and at 15 degrees from center line and at distances of 30 mm, 35 mm, and 40 mm from the center point of ear canal. The amplitude of the bone-anchored hearing aids was approximately 550 g when stimulated by the vibrator. This paper discusses the frequency responses and characteristics of the BAHA vibrator on the mastoid of the temporal bone at the frequencies of 125 Hz, 250 Hz, 500 Hz, 750 Hz, 1 kHz, 2 kHz, 3 kHz, 4 kHz, 5 kHz, 6 kHz, 7 kHz, 8 kHz. Based on the results of conducting modal analysis of the temporal bone, 11 natural frequencies, 125 Hz, 250 Hz, 500 Hz, 750 Hz, 1 k Hz, 2 kHz, 3 kHz, 4 kHz, 5 kHz, 6 kHz, and 7 kHz, included the stimuli frequencies of pure tone audiometry. Based on the results obtained by conducting harmonic analysis of the temporal bone, the performance of bone conduction at 35 mm and at 15 degrees was higher than those at 0 and -15 degrees.

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