破裂速度快于剪切波的速度
1Graduate Aeronautical Laboratories, California Institute of Technology, Pasadena, CA 91125, USA.
概括
动态断裂理论表明,表面波速是极限. 然而,实验表明剪切裂可以超过这一点,以两倍的剪切波速度传播,类似于地震破裂.
科学领域:
- 固体力学 固体力学是什么
- 材料科学 材料科学 材料科学
- 地质物理学 地质物理学
背景情况:
- 经典的动力断裂力学假定表面波速是弹性材料的内平面裂传播的最大值.
- 这一理论极限一直是理解压力下材料故障的长期假设.
研究的目的:
- 在动态断裂中实验挑战已建立的表面波速度限制.
- 为了研究超越经典预测的裂传播动态.
主要方法:
- 在不对称负荷下,在易碎的聚树脂中实验观察裂纹生长.
- 分析裂传播速度和相关的波浪现象.
主要成果:
- 经过交声剪切主导的裂纹生长,超过了表面波速度限制.
- 观察到伴随裂的剪切冲击波以大约两倍的剪切波速度传播.
- 确定了观察到的裂行为和地震破裂动态之间的相似之处.
结论:
- 实验证据与关于传播速度限制的经典动态断裂理论相矛盾.
- 由剪切驱动的声际裂速是可以实现的,并产生明显的波纹.
- 这些发现提供了对诸如浅层地震断裂等现象的见解.
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