棒料热应力预制裂纹的数值模拟研究

利用ANSYS软件建立棒料的有限元分析模型，并对其温度场和应力场进行仿真计算。采用无交互作用方差法，得出绝热边界对喷水时间的影响比水流速度对喷水时间的影响大的分析结果。实验结果表明：当绝热边界的宽度为0时，V形槽尖端不产生裂纹；当绝热边界的宽度大于0．693mm（V形槽宽度的一半）时，在相同的绝热边界宽度下，水流速度越大，所需的喷水时间就越短，而在相同水流速度下，绝热边界的宽度越大，则所需的喷水时间就越长。为了更好地预制V形槽尖端理想裂纹，应使绝热边界的宽度取最小值，水流速度尽可能地取大值。研究结论对进一步开展热应力实验提供了理论依据。

Numerical Investigation of Ideal Fracture Caused by Thermal Stress

ANSYS software was applied to build the finite element model of the bar,and the temperature field and the stress field were simulated numerically. The width of the adiabatic boundary ex erts a remarkable influence on the spraying time by means of method of analysis of variance. The experimental results show that under the same width of the adiabatic boundary that is bigger than 0. 693mm,the spraying time decreases with the increase of water velocity, and under the same water velocity condition,the spraying time decreases as the width of the adiabatic boundary increases. The minute fracture can not appear near the tip of V shaped groove under zero width of the adiabatic boundary. It is the best choice that the width of the adiabatic boundary is 0. 693mm and the water velocity is even higher for obtaining the fracture as quickly as possible. The obtained results are helpful for the test of the thermal stress.