爆炸荷载作用下焊接工字钢梁的动力响应及破坏模式分析

目的分析焊接工字形钢梁在爆炸荷载作用下破坏模式及影响动力响应的主要因素，为钢梁抗爆设计提供建议．方法采用有限元软件ANSYS／LS—DYNA，基于流固耦合的方法对钢梁的动力响应及破坏进行数值分析．结果在不同的爆炸荷载作用下，钢梁可能发生剪切破坏、弯剪联合破坏和翼缘屈曲破坏3种破坏模式；增高腹板高度可以有效地控制钢梁在爆炸荷载作用下的跨中最大位移，效果次之的是增加翼缘板厚度和腹板厚度，效果最差的是增加翼缘板宽度．结论钢梁的破坏模式与比例距离有关．随着比例距离增大，钢梁的破坏模式由剪切破坏模式转变为翼缘屈曲破坏模式．增大梁截面高度，能有效地提高钢梁的抗爆承载力．

Analysis of Dynamic Responses and Failure Modes of Welded I-Shaped Steel Beams Subject to Blast Loadings

The purpose is to study failure modes and the main factors for the dynamic responses of welded I- shaped steel beams subjected to blast loading, to provide some suggestions. Dynamic responses of steel beams under blast loading are numerically analyzed based on the fluid-structure coupling method using the finite element software ANSYS/LS-DYNA. The analysis results show the beam can take place shear failure, combined failure of bending-shear, flange buckling failure under the different blast loadings;the maximum midspan displacement of welded I-shaped steel beam under blast loading can be efficiently controlled with increasing the web height, the effect of increasing the flange plate thickness and web thickness is second, and increasing the width of flange plate is the worst. It is found that the failure modes of steel beam are related to the scale distance. The failure modes of steel beam transfer from shear failure mode into the flange buckling failure mode with increasing of the scale distance. The blast resistance capacity of steel beam can be effectively improved especially with increase of the web height.