Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 162 for “"material model"”.
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Dynamic simulation of heart mitral valve with transversely isotropic material model
… simulating, in the finite element setting, the material behavior of heart mitral valve leaflet tissue. First, a mixed pressure-displacement formulation is used to implement the constitutive material behavior with general 3D elements. Second, a shell is formulated that incorporates the 3D …
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Development of a Micromorphic (Multiscale) Material Model aimed at Cardiac Tissue Mechanics
… has historically relied on classical continuum models; however, classical models amalgamate the behaviour of a material's micro-constituents, and thus only approximate the macroscopically observable material behaviour as a purely averaged response that originated on micro-structural levels. As …
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Development of a fatigue tester and material model for flexible heart valve applications
The leaflet material in heart valve prostheses is required to be both flexible and durable to eliminate the need for chronic anticoagulation medication and accommodate younger patients with longer life expectancies. This investigation aims to provide two of the necessary tools to design and test …
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Identification of material model parameters using full-field metrology, inverse techniques and uncertainty quantification
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2026-08-01
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A coupled, two-phase fluid-sediment material model and mixture theory implemented using the material point method
A thermodynamically consistent constitutive model for fluid-saturated sediments, spanning dense to dilute regimes is developed from the integral form of the basic balance laws for two-phase mixtures. This model is formulated to capture the (i) viscous inertial rheology of wet grains under steady …
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Numerical Modeling Issues in Finite Element Simulation of Plasticity Induced Crack Closure With an Emphasis on Material Model Effects
… As a crack grows through previously yielded material, the permanent deformation in the crack wake Shields the crack tip from the full impact of the remote load. This work sought to add to the large body of PICC finite element studies by introducing two nonlinear plasticity models---nonlinear …
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Implementation of material models for high strain rate applications as user-subroutines in abaqus/explicit
… to allow users to supplement its existing material model library with user-defined material models (VUMATs). This thesis involves the implementation and verification of the Johnson-Cook and Zerilli-Armstrong material models as VUMATs. The same version of the Johnson-Cook material model is …
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Prediction of early-age cracking of UHPC materials and structures : a thremo-chemo-mechanics approach
… UHPC cracking, there is a need to develop a material model that captures the behavior of UHPC at early-ages. The objective of this research is to develop a new material model for early-age UHPC through a thermodynamics approach. The new model is a two-phase thermo-chemo-mechanical model, …
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Computational Stress and Deformation Analysis of Mammary Prosthesis
A linear and non-linear material model for the breast implants was developed through axial tension testing, while linear and non-linear breast tissue models were assumed based on smooth muscle. These material models were to develop axisymmetric finite element models to determine the stresses in the …
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A Non-linear Visco-elastic Model for Dynamic Finite Element Simulation of Bovine Cortical Bone
Modelling and simulation of the human body during an impact situation such as a car accident, can lead to better designed safety features on vehicles. In order to achieve this, investigation into the material properties and the creation of a numerical model of cortical bone is needed. One approach …
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Validation of hygrothermal material modelling under consideration of the hysteresis of moisture storage
… is significantly dependent on the applied material functions. These functions are determined by the material modelling marking the connection between the basic storage and transport parameters which are obtained from basic measurements, and the storage and transport coefficients which are …
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Finite element analysis of self-pierce riveting in magnesium alloys sheets
… state variable (ISV) plasticity and damage material model was employed with results in good agreement to experimental data. The results of this study show that the ISV material model is ideally suited for modeling the SPR process in magnesium alloys.
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Modelling of welding with various constitutive models for steel
… attempt at the quality analysis of constitutive modelling of welding as a coupled thermo-mechanical or thermo-mechanical-metallurgical problem. Three types of inelastic theories of continua: unified viscoplasticity based on dislocation density theory, unified viscoplasticity based on potential …
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The numerical modelling of transformation induced plasticity in the deep drawing of stainless steel
… of the processes and in the understanding of the material forming itself. This thesis document describes the development and formulation of a material model which was used in the numerical simulation of deep drawing problems. The purpose of the material model was to predict the formation of …
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Probabilistic Analysis of the Material and Shape Properties for Human Liver
… inter-subject variations into numerical human models. The main objective of this study was to quantify the variations in shape and material properties of the human liver. Statistical shape analysis was applied to analyze the geometrical variation using a surface set of 15 adult human livers …
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Development of Simultaneous Transformation Kinetics Microstructure Model with Application to Laser Metal Deposited Ti-6Al-4V and Alloy 718
… deployment of integrated process-microstructure models has remained as a challenge due to some of the reasons listed below: (1) lack of good process models to consider the laser-material interactions; (2) inability to capture all the heat transfer boundary conditions; (3) …
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Modelling the constitutive behaviour of poly(ethylene terephthalate) for the stretch blow moulding process
… production of PET containers. Understanding and modelling the behaviour of amorphous PET (aPET) is critical for design the optimum product and process.<br/><br/>However due to its nonlinear viscoelastic behaviour, the behaviour of aPET is highly sensitive to its thermomechanical history making …
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Hierarchical material models with microstructure for nonlinear analysis of progressive damage in laminated composite structures
… presents new comprehensive nonlinear structural modeling approaches using hierarchical 3D micromechanical models for the analysis of progressive damage in laminated structures. Each approach is generally a synthesis of three components: a nonlinear material model for the matrix behavior; a …
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Modeling and Analysis of Cyclic Behavior of Sands
The main objective of this study is to develop a material model for sands based on the concepts of the theory of plasticity. The model could be used in finite element analysis of transient behavior of soil structure under dynamic loading. The model, to qualify as an acceptable constitutive law for …
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Uncertainty quantification of vista charring ablator material database using Bayesian inference
… implemented in the spacecraft’s design. Current modeling tools used for the design of heat shields, however, have been shown to be unable to fully replicate material response data recorded during flight. Collaborative efforts aimed at improving current models are also difficult to establish due …
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