Abstract: Previous optimization design methods of independent pile anti-collision structure (such as trees, poles, piers and other road fixed objects) are capable of settling the safety optimization problem of independent pile or vehicle unilaterally, however, the safety performance optimization design for the vehicle and the object impacted can’t be solved simultaneously. A crash compatibility optimization method of independent pile anti-collision structure is proposed. Taking crash compatibility design method of vehicle-vehicle collision as a reference,a crash compatibility study by regarding the independent pile anti-collision structure as “vehicle” and the independent pile as “occupant” is conducted, and the geometry of the independent pile anti-collision structure front end is obtained. Then, according to the lightweight design requirements of the independent pile anti-collision structure, the crashworthiness topology optimization design method is introduced into the stiffness design of independent pile anti-collision structure. The independent pile anti-collision structure topology configuration which the force transmission path is optimal is obtained by means of topology optimization method of the maximum energy absorption principle. The stiffness matching problem of the independent pile anti-collision structure and vehicle is solved, and the deficiency of quality incompatibility between the independent pile anti-collision structure and the vehicle is remedied. By matching the geometric shape and stiffness of front end, it not only ensures the safety of the occupant in the vehicle, but also maximizes the energy absorption capacity of the independent pile anti-collision structure, so the integrity of independent pile is guaranteed. Finally, the proposed method is applied to the design of independent pile protecting trees, and the brand new independent pile anti-collision which can guarantee the integrity of tree and ensure the safety is gained. The feasibility of the proposed method is verified.

Key words: crash compatibility, anti-collision structure, geometry, stiffness, independent pile