汽车撞击与爆炸复合作用下H型钢柱损伤效应分析

Damage Effect Analysis of H-Section Steel Columns Subjected to Synergistic Effects of Vehicle Impact and Blast

为研究H型钢柱在汽车撞击与爆炸复合作用下的抗冲撞与抗爆性能,本文基于非线性分析有限元软件ANSYS/LS-DYNA,通过建立汽车先撞击钢柱后爆炸的全过程模型来模拟汽车撞击与爆炸的复合作用对H型钢柱的损伤破坏.本文对比分析了汽车撞击单独作用、爆炸荷载单独作用与二者复合作用3种工况下H型钢柱动态响应的差异性.同时,采用参数化分析方法,探究H型钢柱在汽车撞击与爆炸复合作用下,轴压比、长细比、钢材强度和截面类型等因素对于钢柱损伤效应的影响.结果表明:汽车撞击偏转致使前翼缘两侧位移差异显著,质心偏移一侧明显高于另一侧;爆炸冲击造成前翼缘两侧位移较为对称,整体位移相对较大.冲击波因汽车的阻挡作用发生反射与绕流现象,致使钢柱因爆炸产生的动力响应减弱.为保证H型钢柱的抗冲撞与抗爆性能,应限制其轴向压力值,若钢材强度选用Q390,则轴压比宜控制在0.4以内.若原选用钢材强度较小,适当提高强度可提升钢柱抗冲撞与抗爆性能,但不能盲目提高.改变长细比对钢柱的抗冲撞与抗爆性能影响较小.在保持柱高与总用钢量一致的前提下,圆形空心型截面钢柱的抗冲撞与抗爆性能最优,H型截面钢柱次之,方形空心型截面钢柱最差且与前两者差距较大.本文研究成果可为后续钢柱抗冲撞与抗爆防护措施的研究提供理论基础.

To investigate the anti-knock and anti-blast performance of H-section steel column under the synergistic effect of vehicle impact and blast,using the finite element software for nonlinear analysis ANSYS/LS-DYNA,the damage effect of the combined vehicle impact and blast loads on the H-section steel column is simulated by establishing the whole process model of vehicle explosion after striking a steel column. The difference of dynamic response of H-section steel columns under three working conditions,i.e. vehicle impact,blast load,and combined impact and blast load,are compared and analyzed. Meanwhile,the influences of the axial compression ratio,slenderness ratio,steel strength,and cross section type on the damage effect of H-section steel column under the combined im-ensure anti-knock and anti-blast performance of the H-section steel column,the axial pressure value of the steel column should be limited;when the steel strength grade is Q390,the axial pressure ratio should be controlled within 0.4. A reasonable steel strength should be chosen for steel column;if the strength of the original steel is small, properly increasing the steel strength can improve the anti-knock and anti-blast performance,but cannot blindly increase the steel strength. Changing slenderness ratio has less impact on the anti-knock and anti-blast performances of steel column. Under the premise of keeping the column height consistent with the total steel consumption,the circular hollow section steel column has the best anti-knock and anti-blast performance,followed by the H-section steel col-umn,and the square hollow section steel column has the worst performance,which has a big gap from that of the former two. The research results in this paper can provide a theoretical basis for further research on the anti-impact and anti-knock protection measures of steel columns.