钛合金基体上TiN涂层的残余热应力分析

采用有限元方法分析TiN涂层的残余热应力,研究钛合金基体和涂层厚度对TiN涂层热应力分布的影响.结果表明:基体内以拉应力为主,涂层内以压应力为主,在明锐界面靠近自由边界处出现了剪切应力奇异场;当涂层厚度增加时,涂层的径向应力逐渐减少,而剪应力先增加随后又趋于平稳;涂层的径向应力随基体厚度增加而增加,当基体厚度超过1 mm时增加变得平缓.     

THE SHOCK WAVES FOR A MIXED-TYPE SYSTEM FROM CHEMOTAXIS

In this paper, we study the shock waves for a mixed-type system from chemotaxis. We are concerned with the jump conditions for the left state which is located in the elliptical region and the right state in the hyperbolic region. Under the generalized entropy conditions, we find that there are different shock wave structures for different parameters. To guarantee the uniqueness of the solutions, we obtain the admissible shock waves which satisfy the generalized entropy condition in both paramete...