阶跃热流冲击加热半无限体动态热应力分析

考虑超快速加热引起传热过程的非傅立叶效应，建立了第二类边界条件下的半无限体的动态热流场，热应力场方程组。用拉普拉斯变换法对方程组进行求解。结果表明，快速加速在半无限体内产生一个热波和两种热应力波。热波通过之时引起当地温度突然升高。应力波的波前通过之时该处应力突然增加；并对热波和弹性膨胀波波速比率对半无限体动态应力的影响作了研究分析。

Study on the Dynamical Thermal Stresses for the Semi-Infinite Body Under the Step Heating Flux Boundary

Based on the modified Fourier law,the equation groups on the thermal stress case for the semi infinite body under step heating flux shock are built.The results obtained by the Laplace method show that the two kinds of stress waves are produced simultaneously inside the body.The following different characteristics are drawn compared with the common Fourier case:(1) The temperature distributions inside the body at any time is discontinuous and the temperature varies suddenly at any locals.(2) With the thermal wave velocity greater than the expanding wave,the shock thermal stresses near the surface are greater than the results obtained by the classical law in a little time after the heating.(3)With the thermal wave velocity less than the expanding wave,only in a little time after the heating ,the shock thermal stresses near the surface are greater than the results obtained by the classical law.In the later time ,the vertex stresses by the classical law are greater than the results obtained by the non classical law.(4) The vertex stresses with the thermal wave velocity greater than expanding waves' are one quantity level greater than that less than the expanding waves'.