应力波在多层介质中传播特性数值分析

NUMERICAL SIMULATION ON STRESS WAVE PROPAGATING IN MULTI-LAYERED MEDIA

通过与相关文献结果的对比 ,在验证了数值模拟应力波传播可行性的基础上 ,比较了应力波通过 3层花岗岩和夹层为泡沫铝的 3层介质后 ,发现后者应力波幅值的衰减远大于前者 ,应变能增加为前者的 1.6倍 ,证明了软夹层在研究的速度量级上对能量耗散具有显著作用 ;在入射波波长为 3层介质总厚度 1/ 2的条件下 ,当泡沫铝的厚度占总厚度约 0 .2时 ,得出了 3层介质的应变能约为系统总能量的 6 0 % ,此时入射波波长为泡沫铝厚度的 2 .5倍 ,组合介质获得较佳的衰减性能 .

The calculational results have been shown f easible by comparing with the experimental results from references. The stress p eak value decreases significantly when the interlayer of granite is replaced by foamed aluminum in the three-layered granite media. Meanwhile, the strain energ y becomes 1.6 times as much as that of the original. It shows that the soft laye r has an important effect on energy dissipation. In the condition of the ratio o f impulse width of input stress wave to the thickness of three layered media bei ng 1/2, and the foamed aluminum thickness occupies 0.2 of the total samples thic kness, that is to say, the impulse width of input stress wave is 2.5 of the foam ed aluminum thickness, the strain energy of the three-layered media accounts fo r approximately 60 percent of total energy. It is more ideal situation on stress attenuation.