用3维实体单元来模拟激光辐照下充压柱壳的应力和应变分布,在光斑边缘采用棱锥单元来处理过渡区,分析了柱壳裂纹萌生的可能位置和条件.通过计算发现:外热源加载的柱壳在时间较短、内压足够大时,裂纹可能会在光斑边缘处产生并扩展开来;在功率相同的条件下,小光斑辐照时易产生裂纹,功率密度相同时,大光斑辐照下易产生裂纹,说明柱壳破坏的一个因素取决于功率密度;柱壳在不同时间,应力与抗拉强度之比分布不同,过光斑中心的柱壳母线上的环向应力在柱壳裂纹的萌生中起主要作用.

When a laser beam irradiates a cylinder shell, the irradiated area becomes softer and will destroy cylinder shell. On the basis of early work, 3-D solid element is adopted to simulate the stress of internally pressured cylinder shell irradiated by laser. The properties of material varying with temperature are also taken into account in the computation. It is analyzed by numerical simulation that the ratio of circumferential stress and strength of outer shell along axis is affected by irradiation time, laser beam spot radius and power . With the computations, it concludes that the crack will initiate from the beam spot edge at the conditions of short heating time and large inner pressure, the smaller beam spot will easily crack at the condition of the same laser power, and that the ratio of stress and strength will vary with the laser heating time.