空穴的绕射隔离效应和对后方应力波的削弱作用

以新型抗爆工程设计为背景，以改进的有限差分软件Renewto为手段，对含空穴的混凝土介质中应力波的衰减机制和演化规律进行了二维数值分析，通过改变空穴的位置和特征尺度等参数来考察空穴后方应力波的强度衰减及波形演化，从而对应力波传播中的空穴隔离效应进行了分析和讨论。结果表明，适当调整空穴的位置、尺寸等因素，可以在其后方明显减弱冲击波。还以计算结果为基础提出了一个应力削弱因子的拟合公式，为在抗爆防震工程中设计科学智能的防护层提供了一定的理论依据。

Insulation effect of the cavity on stress wave

There are many evolution and attenuation mechanisms of stress waves in media, which are mainly controlled by the constitutive factors of the material and the structure’s geometric factors. Scientific utilization of these mechanisms have important academic and engineering values. In this paper the 2-D numerical simulation code RENEWTO are used to study the attenuation mechanism and the evolution law of stress waves in the concrete material with a cavity. By the method of changing the location and the dimension of the cavity, the attenuation of the intensity and the evolution of the shape of the stress wave behind the cavity are discussed, and the insulation effect of the cavity are analysed too. The results show that the cavity weakens the wave intensity behind it greatly. An approximation formula is presented. This work provides an important basis for designing the scientific intelligent safe protected-layer.