摘要
为研究远场爆炸荷载作用下单向砌体填充墙的动力行为及其失效破坏机理,首先,基于研发的压缩空气驱动大截面(3 m×3 m)激波管开展了两面不同厚度单向实心砌体填充墙的面外加载试验,获得了作用在墙体表面的反射超压荷载时程、墙体面外挠度时程及墙体的变形失效模式。其次,建立了激波管精细化有限元模型,提出了砌体墙简化微观有限元建模方法,以及扩展砖块的Riedel-Hiermaier-Thoma材料模型和接缝的内聚力接触模型参数取值计算方法,对激波管中的压力传播以及试验墙体面外动态响应和损伤破坏开展了数值模拟。最后,基于爆炸荷载作用下单向砌体填充墙面外抗力方程和等效单自由度模型对试验墙体中心点面外挠度时程进行预测。结果表明:减小墙体高厚比可以增大框架拱推力,从而显著提升墙体的抗爆性能,厚105 mm的墙体在经历1次激波管试验后发生倒塌,而厚235 mm的墙体在经历6次激波管试验后仅有轻微损伤;墙体表面反射超压荷载时程的试验和数值模拟结果均为均布脉冲型荷载,且两者吻合很好,验证了激波管设计和激波管精细化有限元模型的合理性;数值模拟和理论预测的墙体动力行为与试验结果吻合较好,可为砌体填充墙抗爆评估与分析提供参考。
Masonry-infilled walls(MIWs)are prone to crack,fragment,and even collapse under blast loads,attributed to their low strength and weak ductility,which threatens the safety of building structures and the inside occupants and equipment.Aiming to study the dynamic behaviors and failure mechanism of one-way solid MIWs under far-field range explosion,the out-of-plane loading tests on two one-way solid MIWs with different thicknesses were first carried out based on the developed compressed air-driven large cross-section(3 m×3 m)shock tube.The reflected overpressures-time histories that acted on the MIWs,the deflection-time histories,and the deformation failure mode of MIWs were obtained.Then,a refined finite element model of the shock tube was established,and the simplified micro finite element modeling approach of MIWs,as well as the parameter calculation methods of the Riedel-Hiermaier-Thoma material model for expanded masonry blocks and the cohesive contact model for joints,were proposed.The pressure propagation in the shock tube and the out-of-plane dynamic responses and damage of MIWs were further numerically simulated.Finally,the central deflection-time histories of test walls were predicted based on the out-of-plane resistance function and equivalent single-degree-of-freedom model of one-way MIWs under blast loads.It indicated that reducing the height-to-thickness ratio of walls can increase the frame arch thrust,which could significantly improve the blast resistance performance of the MIWs.A105-mm-thick MIW collapsed after one shot,while a 235-mm-thick MIW was slightly damaged after six shots.Both the test and simulation results of reflected overpressure-time histories acted on the surface of MIWs were uniform pulse loads and in good agreement,which validated the reasonability of the design and refined finite element model of the shock tube.The predicted dynamic behaviors of MIWs by the numerical simulation and theoretical calculation method were in good accordance with test data,which can provide a reference for blast-resistant assessment and analysis of MIWs.
作者
陈德
吴昊
徐世林
韦建树
CHEN De;WU Hao;XU Shilin;WEI Jianshu(College of Civil Engineering,Tongji University,Shanghai 200092,China;Shanghai Dragon Industrial Engineering Co.Ltd.,Shanghai 200122,China)
出处
《爆炸与冲击》
EI
CAS
CSCD
北大核心
2023年第8期134-152,共19页
Explosion and Shock Waves
基金
国家自然科学基金(52078379)。
关键词
激波管
爆炸载荷
砌体填充墙
动力行为
面外加载
反射超压
shock tube
blast load
masonry-infilled wall
dynamic behavior
out-of-plane loading
reflected overpressure
