基底/功能梯度涂层结构的动态热应力分析及结构优化

 研究了金属基底 /功能梯度涂层结构中的动态热应力;对功能梯度材料的梯度指数进行了优化;分析了可能的破坏模式。研究结果表明,加热速度对结构中的热应力分布有很大的影响,存在优化的梯度指数使得结构具有最大的热强度。

THERMAL STRESSES ANALYSIS AND OPTIMIZATION OF SUBSTRATE/FUNCTIONAL GRADED COATING STRUCTURE

The thermoelasticity problem for a functionally graded coating bonded to metal substrate due to transient heating on the coating surface isconsidered. The functionally graded coating is a particulate composite with volume fractions continuously varying through the thickness. The coating was treated with a series of homogeneous layers with stepwise changing volume fractions. The dynamic thermal stresses are analyzed for various coating gradients. It is shown that heating rates have significant influences on the failure mechanism of coating. For larger heating rates, the surface cracking of the coating is caused by compressing stress. While for lower heating rates, the surface cracking of the coating is caused by tensile stress. While failure mechanics of surface cracking in mind, the optimization of coating composition is presented for different heating rates.