Shed Light on Vehicle Structural Integrity 2019-01-0857

The ability to validate design models is critical, especially when accounting for real-world operating conditions. Lightweight materials, such as plastics and carbon fibers, are becoming more prevalent throughout vehicles enabling greater fuel efficiency and safety standards to be met. These materials provide new challenges for validation, requiring more sensors and data to be understood. The use of high-definition fiber-optic sensing (HD-FOS) can provide the data density needed for verifying the performance of these new parts relative to the design intent. With its ability to provide up to 1000 discrete strain locations per meter of fiber, this measurement tool can serve as inputs into computer-aided engineering (CAE) models. Experiments test the ability of the HD-FOS system to make the necessary design measurements demonstrated on a truck under normal driving conditions. Sensors bonded to the lower control arms and a supporting member recorded strain measurements every 1.3 mm along these parts. These locations were chosen for their sensitivity to strain during vehicle operation. The test conditions included highway driving at 113 km/h including a run over rumble strips, speed bumps on town roads, tight turns in a parking lot, and bumpy pothole-stricken forest service roads. The strain range on the control arms was ±200 microstrain whereas the strain range on the supporting member was 100 - 400 microstrain, with a maximum acceleration measured of 14G. No sensor breakages or system failures occurred throughout testing. With a system that can provide real-time high-density strain measurements while enduring tough road conditions, automotive developers will be better equipped to tackle the challenges of using new materials throughout their designs.