激光诱导充压柱壳破坏模式与参数阈值分析

摘要

通过数值计算模拟了激光诱导充压柱壳的热力破坏效应,研究了典型结构的动态爆裂过程,获得的破坏模式与实验结果基本一致.给出了三类典型破坏模式及其对应的参数范围,探讨了各类破坏模式的形成机理,并分析了不同光斑尺寸、壳体厚度条件下热软化效应对破坏内压阈值的影响,以及预内压与破坏时间的关系.研究结果表明:光斑半径越大、热软化程度越高,柱壳的破坏内压阈值越低,且破坏内压阈值随着壳体厚度的减小呈线性下降;给定激光参数和壳体参数下破坏时间随预充内压增大而减小并呈二次函数关系.给出了一种通过热软化程度预估激光诱导充压柱壳破坏时间的方法.%Thermal-mechanical failure behavior of the internally pressurized cylinder shell under laser irradiation is investi-gated by numerical approach.The dynamic bursting processes are simulated,and the obtained failure modes are validated by ex-periment.Three typical failure modes are found and the corresponding parameter ranges are listed,and formation mechanisms of each failure mode are discussed.The effect of thermal softening on the threshold of internal pressure at different laser spot sizes and shell thicknesses are explored,and the relation between internal pressure and failure time is discussed.The results show that the threshold of internal pressure decreases with the increasing laser spot size and the extent of thermal softening,and it is in line-ar relationship with the shell thickness.At given laser parameters and shell parameters,the failure time declines in a quadratic function of internal pressure.A method to predict the failure time of internally pressurized cylinder shell under laser irradiation based on thermal softening factor is proposed and presented.