Engineering Science and Materials Commons^™

Method Of Embedded Imperfections For The Direct Simulation Of Deformation Instabilities In Film-Substrate Structures, Siavash Nikravesh Kazeroni

Mechanical Engineering ETDs

In this dissertation, a novel finite-element methodology called “embedded imperfections” is proposed and employed for computationally simulating various types of deformation instabilities observed in film-substrate structures subjected to mechanical loading. The approach involves the incorporation of elements having distinctive material properties within the film-substrate interface. One can interpret this practice as a deliberate distribution of material defects within the numerical model. It has been shown that embedded imperfections not only can trigger the onset of instability, but also can lead to “direct” simulation of deformation instability problems in that primary and subsequent instability modes can all be captured in a …

Development Of Mbd Model And Analysis Methodology For Vehicle Design, Alfonso Christopher Ponce

Mechanical Engineering ETDs

This thesis is to provide a new methodology that considers the effects the chassis applies during dynamic load to the suspension and the handling characteristics of a road course vehicle. A methodology in which is described in detail as well as an applied demonstration where literature before this thesis, lacks in replication and serves to establish a basis for multi-body dynamic analysis in this area. Two models to be created, rigid and flexible, and to compare each other to study the effects the chassis torsional stiffness has during load transfer. Ultimately, to assist in the design of a vehicle that …

The Mathematical Theory Of Deformation Arrest In Large-Strain Dynamic Plasticity, Brendan A. Kullback

Mechanical Engineering ETDs

Ductile structural components subjected to explosive loadings exhibit a large range of behaviors. The response of beams, walls, and blast doors is estimated using two methods. The engineering level approaches are highly simplified and neglect much of the relevant physics while the use of finite element or shock-code simulation is expensive and not suited to rapid problem solving and parameter studies. In this dissertation, a medium fidelity reduced order modeling approach has been derived to capture the most relevant physics governing rupture of ductile bodies dynamically deforming in tension.

Solution of the inertially stretching jet is used to reveal the …