Abstract The dynamic response of arching unreinforced masonry walls subjected to blast loads combines a spectrum of complex physical phenomena including opening and closing of cracks, unloading and reloading, accumulation of damage, rocking, coupling of in-plane and out-of-plane responses, and time variation of the arching force. These aspects contribute to the complexity of the dynamic behavior of the masonry wall and make the dynamic analysis challenging. This study develops a new model that integrates the aforementioned characteristics of the wall behavior and presents a quantitative tool for the assessment of the complex response. The model assumes one-way flexural action of an unreinforced masonry wall and takes the form of a multi-degree-of-freedom system, where the response is described by the displacements and rotations of the masonry units. The formulation employs variational principles and accounts for equilibrium conditions, cracking, geometrically nonlinear kinematics, and nonlinear and inelastic constitutive laws. The masonry units are assumed rigid bodies, whereas the flexural longitudinal and shear deformations of the wall are due to the mortar strains only. The mortar joints and the interfaces between adjacent masonry units are represented by arrays of nonlinear longitudinal and shear springs that introduce the normal, shear, and contact interactions between blocks. The model is examined and compared against experimental results taken from the literature. The investigated features include the cracking process, the inelastic behavior of the mortar material, and its effect on the wall response. The results demonstrate the capabilities of the analysis and throw light on the dynamic nonlinear response of the arching masonry wall under blast loads.

中文翻译：

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单向拱形砌体墙的爆破响应

摘要 拱形无筋砌体墙在爆炸荷载作用下的动力响应结合了一系列复杂的物理现象，包括裂缝的张开和闭合、卸载和重新加载、损伤累积、摇摆、平面内和平面外响应的耦合、和拱力的时间变化。这些方面导致砌体墙动态行为的复杂性，并使动态分析具有挑战性。本研究开发了一种新模型，该模型整合了上述墙体行为的特征，并提供了一种用于评估复杂响应的定量工具。该模型假设无钢筋砌体墙的单向弯曲作用并采用多自由度系统的形式，其中响应由砌体单元的位移和旋转描述。该公式采用变分原理并考虑了平衡条件、开裂、几何非线性运动学以及非线性和非弹性本构定律。砌体单元假定为刚体，而墙的弯曲纵向和剪切变形仅由砂浆应变引起。砂浆接缝和相邻砌体单元之间的界面由非线性纵向和剪切弹簧阵列表示，这些弹簧引入了砌块之间的法向、剪切和接触相互作用。该模型被检查并与从文献中获取的实验结果进行比较。研究的特征包括开裂过程、砂浆材料的非弹性行为、及其对壁面响应的影响。结果证明了分析的能力，并揭示了拱形砌体墙在爆炸载荷下的动态非线性响应。