关键词: 薄壁圆锥管, 吸能特性, 轴向压缩, 瞬时载荷, 皮尔逊相关系数

Abstract: The axial compression simulation of conical tubes, which had cone inclination from 0° to 40° and wall thickness from 1mm to 2.5 mm, LS-DYNA software was applied to study the influences of cone inclination and wall thickness on the energy absorption characteristics and deformation law of conical tubes. In addition, the instantaneous load correction formula for the wide range of the cone inclination angle(15°~40°) was proposed based on the instantaneous load collapse model of Mamalis conical tube. The results show that the critical angle of the deformation mode is 15°, but the deformation mode is in the stacked mode when the cone inclination is less than 15° and it is in the nested mode when the angle is greater than 15°. Moreover, with the increase of the cone angle, the average load and the specific energy absorption decreases gently, while the initial peak load decreases significantly. It should be noted that with the increase of wall thickness, the crushing mode must transform from the diamond mode into the annular symmetry mode while the average load, the initial peak load and the specific energy absorption increase. The simulation results illustrate that the Mamalis instantaneous load formula is modified by the Pearson correlation coefficient analysis method and the maximum error is less than 10% between the modified value and the simulation value, In addition, the accuracy of the modified formula was verified by the experiments. In brief, the correction formula provides a theoretical basis for revealing the mechanism of crushing of thin-walled tubes with large-scale tapered inclination.

Key words: thin-walled conical tube, energy absorption characteristics, axial compression, instantaneous load, Pearson correlation coefficient