Experimental investigation of the mechanical behavior of polymer crash boxes under impact loading

Today, with the increase in the number of automobiles, traffic accidents that occur during travel also increase. Active and passive safety elements are used in the vehicle in order to ensure both vehicle and passenger safety in case of a possible accident. Crash boxes, which are one of the passive safety elements, provide safety by absorbing the collision energy that occurs in the event of an accident. Polymer materials, whose usage areas have been increasing recently, have started to be used frequently in automobiles with their lightness and especially superior properties about fuel economy. In this study, crash boxes with cubic structure prepared with non-reinforced polyamide PA66, which is one of the engineering polymers, and 35% glass fiber reinforced PA66-GF35 material were experimentally investigated. As a result of the examinations, it was seen that the reinforced crash box had higher strength compared to the non-reinforced one. Drop tests were conducted to compare the mechanical performance of empty crash boxes and crash boxes made of polyurethane foam and 301 stainless steel sheet reinforcement. As a result of the tests, it was seen that the glass fiber reinforced crash boxes absorbs more energy than the non-reinforced one. It was concluded that the polyurethane foam reinforcement did not have much effect in glass fiber reinforced crash boxes, while it provided advantages in terms of deformation behavior and energy absorption in the unreinforced box.