爆炸荷载下钢筋混凝土柱的动力响应及破坏形态分析

在冲击、爆炸荷载作用下结构底层柱的破坏可能导致结构的连续倒塌.利用LSDYNA对爆炸荷载下钢筋混凝土柱的动力响应进行了数值模拟.建立了三维实体钢筋混凝土柱模型,爆炸荷载施加在柱子的前表面.钢筋采用塑性硬化模型.混凝土材料采用脆性损伤模型,考虑了损伤及应变率效应.分别对矩形截面、方形截面的柱子在不同折合距离时的侧向位移和失效情况进行了分析.从结果可以看出,在配筋率相似的情况下,截面面积对柱子的动态响应具有显著的影响.当折合距离约为2.0时,爆炸荷载对两种截面钢筋混凝土柱的影响均可以忽略不计.

Dynamic response and failure modes of RC column under blast load

The failur e o f the reinfor ced concrete ( RC) co lumn o n the g round f loor may result in prog ressiveco llapse o f the w ho le building. The RC columns subjected to the blast pressure w ere analy zed w ith thefinite element pro gram LS-DYNA . A three dimensional solid model w as established for the RC column.Blast loads w ere applied over the fro nt face o f the column. T he iso tr opic and kinematic hardening plast icitymaterial model was applied to the reinforcement . A brit t le damag e model w as applied to simulat ing theco ncrete. T he damag e and str ain rate effect w ere co nsidered in this model. The lateral displacement andfailure mode of square co lumn, rectang ular co lumn under differ ent blast load of co rresponding scaleddistance w ere inv est ig ated and discussed. It can be found from the result s that the area of the cr oss sectionhas significant influence on the dynamic respo nse of the column w ith the similar reinforcement r at io. T heinf luence of blast pressure can be neglected for the tw o ty pes of column w hen scaled distance is 2. 0.