This thesis presents a numerical method of predicting both static and dynamic denting phenomena in automotive body panels. The finite element method is used as a predictive tool to assess panel performance prior to production of tooling. A custom software package has been developed to transform existing finite element forming models into ready-to-run finite element denting models, minimising the effort required to perform dent simulations. Over 50 multi-step finite element models were performed. Each of these models simulated the forming, springback and subsequent denting of either 1. 05mm thick AA5754, or0. 81mm, 0. 93mm or 1. 00mm thick AA6111 aluminum sheet. Experimental validation of dent predictions using this method has shown that the trends in both static and dynamic dent resistance have been captured quite well. These validation studies demonstrated the sensitivity of the results to various parameters such as panel thickness, pre-strain, curvature and thickness, as well as numerical formulation parameters. It has been determined that it is particularly important to use forming data within the denting models for accurate results to be obtained.

An examination of static and dynamic dent resistance of structural panel assemblies representing automotive hoods is described in this thesis. Fabricated panel assemblies incorporating typical components of real automotive parts were tested. The panel assemblies included an AA5754 inner panel using an array of teacup supports and an AA6111 closure panel joined with automotive mastic. The assemblies allowed for parametric assessment of numerous factors affecting dent resistance including: panel thickness, panel curvature, panel support configuration and dent site location. An extensive experimental program evaluated various panel combinations under both static and dynamic denting conditions. The measured results illustrate various trends of the different factors affecting dent resistance. The experimental database allows a qualitative assessment of dent resistance for full-scale automotive parts. The importance of support conditions is highlighted. The influence of mastic thickness is found to be a critical consideration. Numerical simulations of the dent test were undertaken using finite element techniques. The numerical predictions offer varying degrees of accuracy. The quantitative results are limited, due to numerical concerns, but the qualitative trends are generally well captured. As well, the relative importance of the various parametric factors is well represented in the numerical results. The interaction of the components at the teacup supports proved to critical to the predictive ability of the models. The method developed to model the interaction was somewhat limited by the available material models within the numerical code used, but offers promise for improved results in future simulations. The modelling method is readily transferred to full-scale automotive panels for assessment of dent resistance early in the design cycle.

This thesis presents a numerical method of predicting both static and dynamic denting phenomena in automotive body panels. The finite element method is used as a predictive tool to assess panel performance prior to production of tooling. A custom software package has been developed to transform existing finite element forming models into ready-to-run finite element denting models, minimising the effort required to perform dent simulations. Over 50 multi-step finite element models were performed. Each of these models simulated the forming, springback and subsequent denting of either 1. 05mm thick AA5754, or0. 81mm, 0. 93mm or 1. 00mm thick AA6111 aluminum sheet. Experimental validation of dent predictions using this method has shown that the trends in both static and dynamic dent resistance have been captured quite well. These validation studies demonstrated the sensitivity of the results to various parameters such as panel thickness, pre-strain, curvature and thickness, as well as numerical formulation parameters. It has been determined that it is particularly important to use forming data within the denting models for accurate results to be obtained.

An examination of static and dynamic dent resistance of structural panel assemblies representing automotive hoods is described in this thesis. Fabricated panel assemblies incorporating typical components of real automotive parts were tested. The panel assemblies included an AA5754 inner panel using an array of teacup supports and an AA6111 closure panel joined with automotive mastic. The assemblies allowed for parametric assessment of numerous factors affecting dent resistance including: panel thickness, panel curvature, panel support configuration and dent site location. An extensive experimental program evaluated various panel combinations under both static and dynamic denting conditions. The measured results illustrate various trends of the different factors affecting dent resistance. The experimental database allows a qualitative assessment of dent resistance for full-scale automotive parts. The importance of support conditions is highlighted. The influence of mastic thickness is found to be a critical consideration. Numerical simulations of the dent test were undertaken using finite element techniques. The numerical predictions offer varying degrees of accuracy. The quantitative results are limited, due to numerical concerns, but the qualitative trends are generally well captured. As well, the relative importance of the various parametric factors is well represented in the numerical results. The interaction of the components at the teacup supports proved to critical to the predictive ability of the models. The method developed to model the interaction was somewhat limited by the available material models within the numerical code used, but offers promise for improved results in future simulations. The modelling method is readily transferred to full-scale automotive panels for assessment of dent resistance early in the design cycle.

TiNi shape memory alloy is characterized by shape memory and superelastic effects which occur due to reversible martensite transformation. It has been recently found that TiNi alloy has superior dent and wear resistance compared to other conventional materials. The stress-induced martensite transformation exhibited by this alloy contributes to its dent and wear resistance. Much work is required to establish the fundamental principals governing the superelastic behavior of TiNi under wear and indentation conditions. Understanding the superelastic behavior helps to employ superelastic TiNi in applications where high impact loading is expected as in gears and bearings. In this study the superelastic behavior of shape memory alloys under reciprocating sliding wear and indentation loading conditions was investigated. The deformation behavior of superelastic Ti-Ni alloys was studied and compared to AISI 304 stainless steel. Dominant wear and deformation mechanisms were identified.