Dynamic Modeling and Performance Evaluation of Using Spacer Fabrics as Shock Absorbers in Helmet of the Car Passenger

Impact to the head during an accident, severe braking or other driving accidents are one of the causes of injury in the passengers of road vehicles. This issue is much more evident for racing car drivers due to the high speed of the car and maneuvering. One of the driver’s protective tools in this situation is a helmet. In this research, the possibility of using spacer fabric as a shock absorber for the car passenger’s head when crossing over road irregularities is investigated. For this purpose, the effect of the diameter, length and density of the yarns forming the spacer fabric, their inclination angle and the thickness of the top layer of the fabric on the impact force on the head is investigated. First, using the finite element model of the fabric, the effect of the above parameters on the force–displacement characteristics of the fabric is studied. In order to simulate the vehicle movement on the road irregularities, a four degree of freedom model of the vehicle and its passenger has been used. By solving the differential equations of motion of the model using the Rang Kuta method, the impact forces on the head have been obtained for different parameters of the fabric. The results of the simulation showed that by increasing the yarn diameter from 0.2 to 0.3 mm, the average force on the head decreases by 21.9%.