Abstract

We propose a non-ordinary state-based (NOSB) peridynamics model for (i) stress concentration in a plate with a hole under static loading, (ii) blast-induced dynamic brittle fracture process and (iii) subsurface blast-induced damage in steel-reinforced concrete. In this model formulation, fractures take their own natural paths. Damage is captured through a scalar damage variable that transits from an intact state of the material to the fully damaged state in a sharp yet smooth manner. The proposed blast formulation considers the effect of conversion of a material state from solid (explosives reactants) to gaseous state (products) during shock wave detonation. The pressure in explosive gas is evaluated using an equation of state. The interaction between gas and rock is modelled using extrapolated stress based on the considerations of stress continuity and numerical stability at the solid–gas interface. The equations that govern the mechanical deformation and damage, are in the form of coupled integro-differential equations derived based on the Hamilton’s principle. The proposed formulation captures the initial radial cracks and spall fracture in the rock medium under explosive induced both shock energy and gas energy, and the subsurface damaged zone in the steel-reinforced concrete medium. The simulation results of all the three peridynamics models are compared and validated with published results.

中文翻译：

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基于相场的近场动力学实现对脆性固体中爆炸引起的断裂进行建模

摘要

我们提出了一种基于非普通状态（NOSB）的近场动力学模型，用于（i）静态载荷下带孔板中的应力集中，（ii）爆炸引起的动态脆性断裂过程和（iii）地下爆炸引起的损伤钢筋混凝土。在这个模型公式中，裂缝有自己的自然路径。损坏是通过标量损坏变量捕获的，该变量以急剧而平滑的方式从材料的完整状态过渡到完全损坏状态。所提出的爆炸公式考虑了冲击波爆炸期间材料状态从固态（爆炸物反应物）到气态（产物）转化的影响。使用状态方程评估爆炸性气体的压力。基于固气界面应力连续性和数值稳定性的考虑，使用外推应力对气体和岩石之间的相互作用进行建模。控制机械变形和损伤的方程采用基于哈密顿原理导出的耦合积分微分方程的形式。所提出的公式捕获了爆炸引起的冲击能和气体能下岩石介质中的初始径向裂纹和剥落断裂，以及钢筋混凝土介质中的地下损坏区域。所有三个近场动力学模型的模拟结果都与已发布的结果进行了比较和验证。