爆炸荷载作用下钢筋混凝土构件动力响应的数值模拟

Numerical simulation of dynamic response of reinforced concrete member under explosive load

考虑了高应变率下混凝土和钢筋的动态本构模型,根据已有试验资料对炸药、钢筋混凝土构件和两者之间的空气建立数值模型,使用显式动力有限元软件LS-DYNA模拟了空气中点源炸药爆炸产生的爆轰冲击作用于钢筋混凝土构件和爆炸荷载作用下构件动力响应的全过程。结果表明,钢筋混凝土构件受到爆轰冲击的作用区域主要集中在构件迎爆面,构件背爆面受到的绕射冲击作用相比可以忽略;构件内应力波的传播不规则,同一位置处剪切应力波峰值早于弯曲应力波出现,构件的易损部位和爆轰冲击的主要作用位置有关,构件中部较端部更易发生弯曲破坏,而端部较中部更易发生剪切破坏。数值模拟结果和试验数据具有较好的一致性。成果表明,本文的数值模拟方法可以更准确地模拟爆炸荷载作用下钢筋混凝土构件的破坏机理和研究构件抗爆能力。

Considering the dynamic constitutive relations of concrete and steel with high strain rates,a numerical model including powder,RC member and air is introduced.The whole process of detonation impact to RC member caused by point source explosion and dynamic response of RC member is simulated by explicit dynamic finite element software LS-DYNA.The result shows that the detonation impact to RC member is centered on the surface close to the blast point,and the diffract impact can be neglected.The propagation characteristics of stress waves in RC member are irregular,the peak value of shear stress wave occurs earlier than flexible stress wave in same position.The fragile regions of RC member are concerned with the major detonation impact position;the flexural failure of RC member occurs more possibly at the middle position than the ends,while the shear failure works vice versa.The numerical simulation results are consistent with the experimental data.The numerical test method introduced in the present paper can be used to simulate the failure mechanism and antiknock ability of RC member under explosive load more precisely.