近区爆炸作用下砌体填充墙损伤破坏与动态响应的数值模拟

Numerical simulation of damage and dynamic response of masonry infilled wall under near zone explosion

民用建筑中广泛使用的砌体填充墙在爆炸荷载作用下产生的碎块严重威胁着建筑物内部人员和设备的安全。尤其是近区爆炸作用下,墙体会产生更为严重的局部破坏,碎片飞散速度更快,但已有的相关研究工作仍旧较少。基于已有普通黏土烧结砖填充墙的近区爆炸试验,开展了近区爆炸作用下砌体填充墙损伤破坏和动态响应的数值模拟,对比验证了Load Blast法、任意拉格朗日欧拉(arbitrary Lagrange-Eulerian,ALE)法和冲量法模拟近区爆炸荷载作用、预测墙体损伤破坏和动态响应的适用性。通过冲量法进一步讨论了相同比例距离下的爆炸距离、砌块砂浆界面黏结强度以及砌块材料模型的影响。结果表明:近区爆炸中,相同比例距离下,墙体损伤通常随爆炸距离增加而加剧,由局部破坏向整体坍塌破坏模式发展;墙体的抗爆性能随砌块砂浆黏结强度增强而得到强化,主要受剪切失效应力控制;MAT_BRITTLE_DAMAGE和MAT_WINFRITH_CONCRETE模型较MAT_SOIL_AND_FOAM模型预测效果更好。

Under action of explosion load,masonry infilled wall widely used in civil structures can generate fragments to seriously threaten safety of people and equipment inside buildings,especially,under near zone explosion,wall body can cause more serious local damage,and debris can fly faster,but the existing research work is still less.Here,based on near-field explosion tests of ordinary clay fired brick infilled wall,the numerical simulation of damage and dynamic response of masonry infilled wall under near-field explosion was performed.The applicability of the Load Blast method,the arbitrary Lagrange-Eulerian(ALE)method and the impulse method to simulate near-field explosion load and predict wall damage and dynamic response were verified contrastively.The impulse method was used to further discuss effects of explosion distance,bond strength of mortar interface and building block material model under the same proportional distance.The results showed that in near zone explosion,under the same proportional distance,wall body damage usually increases with increase in explosion distance,and develops from local failure to the overall collapse failure mode;the anti-blast performance of wall body is strengthened with increase in bond strength of block mortar,and it is mainly controlled by shear failure stress;the prediction effect of MAT_BRITTLE_DAMAGE model or MAT_WINFRITH_CONCRETE model is better than that of MAT_SOIL_AND_FOAM model.