【摘要】 通过理论推导,分别获得了滚石最大冲击力的脉冲算法、弹塑性算法,采用LS-DYNA软件研究了滚石冲击过程中的冲击力及侵彻深度随冲击时间的变化规律,并结合具体算例对滚石冲击力的Hertz算法、日本算法、瑞士算法、关宝树算法、隧道手册算法、脉冲算法、弹塑性算法及数值模拟结果进行了对比分析,研究得出:LS-DYNA数值模拟结果、日本算法、瑞士算法、弹塑性算法及脉冲算法一致性较好,但脉冲算法所得出的计算结果略微偏小.然后以数值模拟结果及隧道手册算法结果为基础,建立了滚石的冲击力的冲击速度与放大系数的关系曲线,并同时考虑了滚石冲击过程中的恢复系数、冲击角度及滚石重力所带来的影响,从而得出了最终滚石冲击力的LS-DYNA算法,并验证了其适用性.更多还原

【Abstract】 By means of theoretical derivation,the impulse algorithm and elastic-plastic algorithm for the maximum impact force of rockfall are obtained.The change rules of impact force and penetration depth along with impact time in the process of rockfall impact are studied by using LSDYNA software.The results of Hertz algorithm,Japanese algorithm,Swiss algorithm,Guan Baoshu algorithm,tunnel manual algorithm,impulse algorithm,elastic-plastic algorithm and numerical simulation results of the rockfall impact force are compared and analyzed with specific examples.The conclusions drawn show that LS-DYNA numerical simulation results,Japanese algorithm,Swiss algorithm,elastic-plastic algorithm and impulse algorithm have better consistency,but the results of impulse algorithm are slightly smaller.Based on the numerical simulation results and the results of tunnel manual algorithm,the relation curve of impact velocity and magnification factor of rockfall is established,with the effects of the recovery factor,the impact angle and the gravity of the rockfall on the impact force taken into account.Therefore,the LS-DYNA algorithm for calculating the final impact force of rockfall is obtained and its applicability is verified.更多还原