Abstract
High speed desert race vehicles carry speeds exceeding 100 mph over extremely rough terrain. Impacts of the terrain on the chassis transfer directly to the driver are felt in the spine of the driver. This thesis aims to analyse 3D printed impact energy absorbing seat mounts to dampen the impact felt by the driver and predict high strain rate behavior with low strain testing. The maximum load that a human spine can take during compression is 3700 N (831.8 lbf). This thesis uses polylactic acid (PLA) as the primary material in a cantilever geometry. The design incorporates standard mounting hole locations in accordance with current seat manufacturers. The load condition is similar to a 200-pound individual experiencing an acceleration three times greater than the acceleration due to gravity. This estimate is for a high-speed chassis hit when the suspension reaches its lowest point.
The experimental process involves inserting the manufactured part into the seat mounts using the pre-designed holes. To subject the component to a compressive load until it reaches its breaking point. The hydraulic universal testing machine was used. They then calculate the impact load based on the experimental results. After removing the damaged structure, they evaluate its impact resistance. A digital microscope was utilized to inspect the block's structure and examine the microstructure. The accuracy of the calculations was assessed by comparing the analytical and experimental results. The microstructure and porosity studies help identify the material's behavior under impact and potential areas for design or printing process optimization. The goal of this research is to advance our understanding of PLA's suitability for high-impact automotive applications, particularly in race car components. 3D printed PLA seat mounts did not perform as expected in experiments. The thinner mounts failed at much lower loads than predicted, while the thicker mounts, although strong enough to protect the spine, also failed sooner than expected. This highlights the need for real-world testing and suggests that computer simulations may not always be accurate. The failures were caused by the material stretching, not breaking, and the way the layers of the print bond together could be improved. Further research into better printing techniques and different materials could make 3D printed car parts safer and more reliable.