砌体填充墙作为非结构构件在建筑结构抗爆分析中常被忽略,而实际爆炸事故中填充墙多发生严重破坏,从而影响爆炸波的传播及其与结构的相互作用以及结构的损伤破坏等级.基于精细化数值仿真方法评估外部爆炸作用下砌体填充墙对钢筋混凝土(reinforced concrete,RC)框架结构损伤破坏的影响.首先,采用LS-DYNA有限元分析软件分别对典型砌体填充墙和含填充墙RC框架的近区爆炸试验进行复现,验证所采用的填充墙简化微观建模方法、材料本构模型和参数,以及任意拉格朗日欧拉爆炸荷载施加方法和爆炸波-结构流固耦合算法的适用性.进一步结合结构混合单元建模方法,开展了美国联邦应急管理署规定的普通轿车炸弹(454 kg TNT当量)在底层边柱位置爆炸下,6度、7度和8度抗震设防烈度的典型6层纯框架和含填充墙框架结构动力行为的数值仿真分析,考察了爆炸波传播路径,以及结构的动态响应、损伤破坏和抗倒塌机制.结果表明:该工况中填充墙能够有效阻挡爆炸波的传播,作用于目标柱相邻内柱上的超压峰值降低95%,减轻了内部构件的损伤程度;但同时加剧了结构迎爆面的损伤破坏,如3种抗震设防烈度的含填充墙框架目标柱柱中侧向位移较纯框架分别增加21.4%、31.1%和14.8%;不同抗震设防烈度的纯框架和含填充墙框架的顶层目标柱竖向位移基本相同,即抗震设防烈度及砌体填充墙对框架结构整体倒塌行为的影响可以忽略.
Masonry infilled walls as non-structural components are often neglected in anti-blast analysis of building structures.However,in actual explosion accidents,infilled walls often undergo severe damage to affect propagation of explosion wave and the interaction between them and structure as well as levels of damage and failure of structure.Here,effects of masonry infilled walls on damage and failure of reinforced concrete(RC)frame structures under external explosion were evaluated based on refined numerical simulation methods.Firstly,the finite element analysis software LS-DYNA was used to replicate near-field explosion tests of typical masonry infilled walls and RC frames containing infilled walls,respectively to verify the applicability of the simplified micro-modeling method,material constitutive model and parameters as well as arbitrary Lagrange Euler explosion load exerting method and explosion wave fluid-structure interaction algorithm.Furthermore,combined to the structural hybrid element modeling method,numerical simulation analysis was performed for dynamic behaviors of typical 6-story pure frame and a frame structure containing infilled walls with aseismic fortification intensities of 6,7,and 8 degrees under explosion of a regular sedan bomb of 454 kg TNT(Trinitrotoluene)equivalent at bottom layer edge column position specified by US Federal Emergency Management Agency to investigate propagation path of explosion wave as well as dynamic response,damage,failure and anti-collapse mechanism of structure.The results showed that infilled wall under working conditions mentioned here can effectively block propagation of explosion wave,reduce overpressure peak values acting on adjacent inner columns of target column by 95%,and reduce damage degree to internal components;at the same time,it exacerbates damage and destruction of structural explosion-facing surface,lateral displacements at target column middle of frame containing infilled walls with 3 aseismic fortification intensities increase by 21.4%,31.1%and 14.8%,compared to pure frame,respectively;vertical displacements at top layer target column in pure frame with 3 aseismic fortification intensities and frame containing infilled walls are basically the same,so effects of aseismic fortification intensities and masonry infilled walls on the overall collapse behavior of frame structure can be ignored.