Engineering Commons^™

Finite Element Analysis Of The Implantation Of A Self-Expanding Stent: Impact Of Lesion Calcification, Shijia Zhao, Linxia Gu, Stacey R. Froemming

Department of Mechanical and Materials Engineering: Faculty Publications

In this work, the deployment of a self-expanding stent in a stenosed artery was evaluated through finite element analysis. The three-layered structure of the artery and their material properties were measured and implemented in our computational models. The instant outcomes, including lumen gain, tissue prolapse, and stress distribution, were quantified, and the effect of plaque calcification was evaluated. Results showed that the peak wall stress occurred on the media layer regardless of plaque calcification. The calcified plaque mitigated the tissue prolapse and arterial wall stresses in general, compared with the soft plaque. However, the lesion calcification led to a more …

Three-Dimensional Modeling Of Carbon/Epoxy To Titanium Single-Lap Joints With Variable Adhesive Recess Length, Yi Hua, Linxia Gu, Michael Trogdon

Department of Mechanical and Materials Engineering: Faculty Publications

The objective of this paper was to investigate the performance of recessed single-lap joints with dissimilar adherends through the finite element method. The influence of material and geometric nonlinearity of the adhesive as well as the impact of the recess length was examined in terms of maximum principal stresses. The strength of the joint was obtained as the load to initiate the crack propagation. Results suggested that either adding a spew fillet or considering the adhesive plasticity led to reduced peak stresses at the edge of the adhesive layer. The presence of a spew fillet in the single-lap joint with …

A Combined Quadtree/Delaunay Method For 2d Mesh Generation, Simon Tang

Masters Theses 1911 - February 2014

Unstructured simplicial mesh is an integral and critical part of many computational electromagnetics methods (CEM) such as the finite element method (FEM) and the boundary element method (BEM). Mesh quality and robustness have direct impact on the success of these CEM methods.

A combined quadtree/Delunay 2D mesh generator, based on the early work of Schroeder (1991, PhD), is presented. The method produces a triangulation that approximates the original geometric model but is also topologically consistent. The key advantages of the method are: (a) its robustness, (b) ability to create a-priori graded meshes, and (c) its guaranteed mesh quality.

The method …

Impact Of Truck Loading On Design And Analysis Of Asphaltic Pavement Structures- Phase Iii, Yong-Rak Kim, Hoki Ban, Soohyok Im

Mid-America Transportation Center: Final Reports and Technical Briefs

This study investigated the impact of the realistic constitutive material behavior of asphalt layer (both nonlinear inelastic and fracture) for the prediction of pavement performance. To this end, this study utilized a cohesive zone model to consider the fracture behavior of asphalt mixtures at an intermediate temperature condition. The semi-circular bend (SCB) fracture test was conducted to characterize the fracture properties of asphalt mixtures. Fracture properties were then used to simulate mechanical responses of pavement structures. In addition, Schapery’s nonlinear viscoelastic constitutive model was implemented into the commercial finite element software ABAQUS via a user defined subroutine (user material, or …

The Impact Of Wire Stent Fabrication Technique On The Performance Of Stent Placement, Shijia Zhao, Xiangyi (Cheryl) Liu, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

Braided wire stents demonstrate distinct characteristics compared to welded ones. In this study, both braided and welded wire stents with the same nominal dimensions were crimped inside a sheath and then deployed into a stenosed artery using finite element analysis. The braided wire stent was generated by overlapping wires to form crisscross shape. A welded wire stent was created by welding the intersection points of wires to avoid sliding between wires. The effect of fabrication technique on mechanical behavior of Nitinol wire stents was evaluated. The results showed that relative sliding between wires reduced the deformation of the braided stent, …