Study Of Urban Rail Vehicle Crashworthiness And Energy-absorbing Structure

With the rapid development of rail transit and continuously increase of traffic volume,the operating safety(divided into active safety and passive safety) of rail vehicle have received more and more attentions. From the point of accidents happened in the past, only depending on active safety technology can not ensure passengers' life security and prevent vehicle body from damaging in a collision accident, so the passive safety technology of rail vehicle has now become an important subject for domestic and foreign rail vehicle researchers.In this paper, firstly, both the collision processes of three thin walled tubes(circular,square and conical) of same thickness and the working process of a tube crush energy-absorbing structure in B-type subway head car were respectively simulated by use of ANSYS/LS-DYNA, with their change curves of energy absorption as well as impact force to time obtained. In terms of these data, their crashworthiness are studied and evaluated.Secondly, based on the principle that metal cutting process will consume a huge amount of energy, the processes of tool cutting workpiece with different parameters(tool rake angle,cutting depth, workpiece material, shape, etc.) were simulated, and the influences of above parameters in the process were explored. The results show that the energy-absorbing process of tool cutting workpiece is just like the one of tube crush, but the average impact force in cutting process is much less than in tube crush process, and the amplitude of impact force in cutting process is also smaller. After different cutting energy-absorbing structure were simulated and their characteristics were evaluated, the energy-absorbing effect of cutting-crash structure comes to be best.Finally, the processes were respectively simulated of B-type subway head car impacting fixed rigid wall face to face in three conditions, namely without anti-climbing energy-absorbing structure, with crush anti-climbing energy-absorbing structure, and with cutting anti-climbing energy-absorbing structure at the speed of 12.25km/h and 18.36km/h.The results indicate that:(1) the absorbed energy of head car's side beam and bumper beam with cutting anti-climbing energy-absorbing structure is reduced 93.6% and 57.5% than without anti-climbing energy-absorbing structure, and reduced 23.6% and 29.3% than with crush anti-climbing energy-absorbing structure;(2) the head car with crush anti-climbing energy-absorbing structure has the smallest initial force peak, accounting for 38.3% and46.2% of one without anti-climbing energy-absorbing structure, 78.6% and 97.3% of the one with the cutting anti-climbing energy-absorbing structure;(3) with crush or cutting anti-climbing energy-absorbing structure, the deceleration of head car is only 19.7% or 48.9%of the one without energy-absorbing structure, and in both conditions, the plastic deformation of the head car body can be greatly reduced.