建筑物外部爆炸超压荷载的数值模拟

Numerical simulation on blast overpressure loading outside buildings

在对易于遭受爆炸危害的建筑物进行抗爆设计与加固时,首先需要确定作用在建筑物上的爆炸超压荷载模型。但是由于受到建筑物自身特征及周围环境等多种因素的影响,作用在建筑物上的爆炸超压荷载十分复杂。为了掌握作用在建筑物上的爆炸超压荷载的特性,应用非线性显式动力分析软件建立了建筑物外部爆炸超压荷载的数值分析模型,分析了网格划分尺寸的大小对爆炸超压荷载计算结果的影响,模拟了建筑物外部的刚性地面上发生爆炸的过程,研究了爆炸冲击波在建筑外部空间中的传播与衰减规律,以及作用在建筑物外表面的爆炸超压荷载的特性。模拟了邻近建筑物对爆炸冲击波的反射和阻挡作用,同时研究了邻近建筑物的几何尺寸和位置等因素对作用在目标建筑物上的爆炸超压荷载的影响,从而为在建筑物的抗爆设计与加固中确定合理的爆炸超压荷载模型提供了理论依据。

In the design and retrofitting of a building exposed to blast threats, the blast overpressure loading on the building should be calculated firstly. But the propagation of blast shock wave is influenced by many factors, such as the characters of the objective building, the positions of surrounding buildings and so on. Therefore, the blast overpressure loading on buildings were complicated. In order to study the properties of blast overpressure loading on buildings, the numerical models for calculating the blast overpressure loading outside buildings are established using explicit dynamic nonlinear finite element software, the influence of grid size used in the numerical model on the result of blast overpressure loading analyzed, the process of explosion on the rigid ground outside the building and the propagation and attenuation of blast shock waves in the outside space of buildings simulated, the properties of blast overpressure loading outside the buildings studied, the reflecting effect and blocking action of adjacent buildings simulated, the influences of geometrical sizes and positions of adjacent buildings on the blast overpressure loading on the objective building analyzed, and based on the numerical results, some principles in the design and retrofitting of a blast-resistant building proposed to calculate reasonable blast overpressure loading on the building.