钢筋混凝土板在爆炸荷载作用下的破坏模式分析

Failure Mode Analysis for RC Slab under Explosive Loads

目的更精确的界定和证明钢筋混凝土板在不同峰值压力、不同作用时间的爆炸荷载作用下发生的破坏模式变化的规律.方法采用有限元软件Abaqus对钢筋混凝土板的破坏模式进行分析,并考虑了钢筋混凝土的应变率效应.结果Abaqus的数值模拟结果显示,钢筋混凝土板在4种不同峰值压力、不同作用时间的爆炸荷载作用下会发生弯曲和剪切两种不同的破坏模式.结论钢筋混凝土板在相同强度的脉冲压力作用下会发生不同的破坏模式,随着峰值压力的增加与作用时间的减小,破坏模式逐渐由弯曲破坏转变为剪切破坏.爆炸峰值压力较小,作用时间较长时钢筋混凝土板主要发生板边缘和板中部的弯曲破坏;而在爆炸峰值压力较大,作用时间较短时主要发生支撑处的剪切破坏.

Explosion is a kind of load acted on the buildings with powerful energy and short duration compared with normal loads. RC slabs are the very common members for buildings and they will have different failure modes, which usually include flexural and direct shear ones, with the changes of peak pressure and duration time of explosive load. At first the explosive load on buildings can be simplified into triangle impulse pressure in order to make the simulation easier and then a one-way RC slab under the explosive load can be used as an example to be analyzed by the powerful FEM soft ware - ABAQUS to simulate numerically the behaviors of the slab. The dynamic increasing factor (DIF) and strain rate effect on concrete and reinforcement materials are used. Flexural and shear failure modes as well as strength rules are also applied in the paper. At last the failure modes for the RC slab under the different loads are given by the comparison of analysis results for the same impulsive but different peak pressures and duration time of explosive loading.