Crash response planning is a vital component of emergency management and highway emergency response planning. Evaluation of coverage of medical facilities is required to determine adequate access from crash sites to medical facilities. This study proposes a proof of concept for a planning tool that evaluates fatal and serious injury crash response coverage from crash sites to medical facilities in the Commonwealth of Virginia. Calculated travel times from fatal crash sites to medical facilities are compared with reported travel times to better estimate travel time modification factors. The modified travel times are used to determine coverage areas and evaluate serious injury crash response coverage of medical facilities in Virginia. A geo grid approach is used to demonstrate the proof of concept for a crash response planning tool. A risk grid is developed based on the aggregate number of fatal and serious injury crashes. This study includes serious injury crash response coverage because the number of serious injuries and serious injury rate are now included as reportable safety performance measures for state highway safety agencies. A mitigation grid is developed based on the travel time to the closest facility. Finally, a planning grid that combines risk and mitigation factors based on a decision matrix is presented. The resulting tool serves as a proof of concept for developing a crash response planning tool which enables planners to identify areas that do not have timely access from crash sites to medical facilities. / Master of Science / An objective of emergency responders is to safely transport crash victims from crash sites to medical facilities. Ensuring adequate access is an important goal of highway safety professionals. This study proposes a proof of concept for a planning tool that evaluates this access in the Commonwealth of Virginia. This study focuses on serious injury crash sites because the number of serious injuries and serious injury rate are now included as reportable safety performance measures for state highway safety agencies. Travel times from serious injury crash sites to medical facilities are used to identify areas that do not have timely access. Risk and mitigation assessments are performed by dividing the study area into equal sized cells. Risk and mitigation assessments are based on number of crashes and response travel times to the closest medical facility, respectively. These assessments are used to generate a proof of concept for a crash response planning tool which enables planners to identify areas that do not have timely access from crash sites to medical facilities.

One of the principal energy absorbing structural components that influences the crashworthiness of a vehicle is the side-rail, which is also commonly referred to as an s-rail due to its shape that is reminiscent of an “s”. To improve the crashworthiness of a vehicle, in the wake of significant environmental pressures requiring vehicle light-weighting, the parameters that govern the crash response of the s-rail and the implications of light-weight material substitution need to be better understood. In this work, the main parameters that govern the crash response of an s-rail and the variables that influence them were identified and assessed through a combined experimental and numerical modelling programme. In particular, the as-formed properties of aluminium alloy s-rails, due to the tube bending and hydroforming fabrication route were examined. Tube bending, hydroforming and crash experiments were conducted to examine and assess the effects of initial tube thickness, strength, geometry, bend severity, work hardening, thickness changes and residual stresses on the crash response of the s-rail. The forming process variables, springback, thickness, strains, and force and energy response measured in the experiments were used to validate the finite element models developed herein. The validated numerical models of tube bending, hydroforming and crash provided additional insight and also allowed further investigation of the parameters governing the crash response of s-rails. The relevant parameters governing the crash response of s-rails were isolated and the basis for a set of design guidelines, in terms of maximizing energy absorption or minimizing mass, was established. The overall size is the most influential design parameter affecting the energy absorption capability of the s-rail, followed by the initial thickness, material strength, cross-sectional geometry, bend severity and hydroforming process employed, and finally boost in bending. The most significant conclusion made based on this research is that the effects of forming history must be considered to accurately predict the crash response of the s-rail. There are additional conclusions with respect to the tube bending and hydroforming processes, as well as s-rail crash response, that will contribute to improving the design of s-rails for better crashworthiness of vehicles.

One of the principal energy absorbing structural components that influences the crashworthiness of a vehicle is the side-rail, which is also commonly referred to as an s-rail due to its shape that is reminiscent of an “s”. To improve the crashworthiness of a vehicle, in the wake of significant environmental pressures requiring vehicle light-weighting, the parameters that govern the crash response of the s-rail and the implications of light-weight material substitution need to be better understood. In this work, the main parameters that govern the crash response of an s-rail and the variables that influence them were identified and assessed through a combined experimental and numerical modelling programme. In particular, the as-formed properties of aluminium alloy s-rails, due to the tube bending and hydroforming fabrication route were examined. Tube bending, hydroforming and crash experiments were conducted to examine and assess the effects of initial tube thickness, strength, geometry, bend severity, work hardening, thickness changes and residual stresses on the crash response of the s-rail. The forming process variables, springback, thickness, strains, and force and energy response measured in the experiments were used to validate the finite element models developed herein. The validated numerical models of tube bending, hydroforming and crash provided additional insight and also allowed further investigation of the parameters governing the crash response of s-rails. The relevant parameters governing the crash response of s-rails were isolated and the basis for a set of design guidelines, in terms of maximizing energy absorption or minimizing mass, was established. The overall size is the most influential design parameter affecting the energy absorption capability of the s-rail, followed by the initial thickness, material strength, cross-sectional geometry, bend severity and hydroforming process employed, and finally boost in bending. The most significant conclusion made based on this research is that the effects of forming history must be considered to accurately predict the crash response of the s-rail. There are additional conclusions with respect to the tube bending and hydroforming processes, as well as s-rail crash response, that will contribute to improving the design of s-rails for better crashworthiness of vehicles.

In this thesis the sheet metal forming effects such as plastic strain and thickness changes in the crash have been investigated by numerical analysis. The sheet metal forming histories of the components of the load path that absorbs the highest energy during a frontal crash have been considered. To find out the particular load path, the frontal crash analysis of Ford F250 Pickup has been performed at 56 kph into a rigid wall with finite element analysis without considering the forming history. The sheet metal forming simulations have been realized for each structural component building up the particular load path. After forming histories have been acquired, plastic strain and thickness distributions have been transferred to the frontal crash analysis. The frontal crash analysis of Ford F250 Pickup has been repeated by including these to introduce the effect of forming on crash response of the vehicle. The results of the simulations with and without forming effect have been compared with the physical crash test results to evaluate the sheet metal forming effect on the overall crash response. The results showed that with forming history the crash response of the vehicle and deformations of the particular components have been changed and the maximum deceleration pulse transferred to the passenger compartment has decreased. It has seen that a good agreement with physical test results has been achieved.