Abstract:
Vehicle collision test is one of the tests that must be carried out for the safety of vehicles. Generally, elastic rope catapult system is used to increase the sled to a standard required speed, and then the sled collide with the deceleration device to reproduce the actual vehicle collision. However, the catapult process is affected by many factors such as the number and the elasticity coefficient of the elastic rope, the quality of the sled. In order to command the catapult ability of the test bench, precisely control the catapult speed, the deformation of the elastic rope and the movement of the sled during the catapult process were analyzed based on the vehicle collision test with the elastic rope catapult. The relevant mechanical model is established and a numerical discrete method is proposed to solve the model numerically in this paper. With a specific example, the influences of the initial catapult distance, the quality of the sled, the number and the elasticity coefficient of the elastic rope on the movement of the sled are studied. The results show that the resultant force of the sled increases with the increase of the initial catapult distance, the number and elasticity coefficient of the elastic rope while the mass of the sled has little effect on the resultant force during the catapult process. The initial acceleration of the sled increases with the increase of the initial catapult distance, the number and the elasticity coefficient of the elastic rope decrease with the increase of the quality of the sled. The speed and displacement of the sled change quickly with the increase of the initial catapult distance. Such change also will be greater with the weight increase of the sled, with the increase of rope number and with the increase of elasticity coefficient of the rope.