Analysis of a barb test for measuring the mixed-mode delamination toughness of coatings
Analysis of a barb test for measuring the mixed-mode delamination toughness of coatings
复制标题
DOI：
10.1016/j.actamat.2007.08.052
复制
发表时间：
2008
期刊：
影响因子：
9.4
通讯作者：
Yufu Liu;Y. Kagawa;A. Evans
中科院分区：
文献类型：
--
作者：
Yufu Liu;Y. Kagawa;A. Evans
在大多数涡轮机发动机中使用的热障涂层（TBC）的耐久性受到涂层内和涂层-基底界面处的分层的限制。通过确定稳态能量释放率、模态混合度和屈曲临界长度，对用于评估与此类脱层相关的混合模态韧性的试验进行了全面分析。基于梁理论的解析解建立了基本估计和比例关系。选定的有限元计算已被用来确认的保真度的结果。能量释放率达到稳定状态，但相位角的变化，因为一个小的（但显着的）弯曲力矩在支持。涂层在临界脱层长度处失稳，此时能量释放速率迅速增加，并违反稳态。的解决方案是用来重新解释测量报告中的电子束物理沉积TBC的文献。
The durability of thermal barrier coatings (TBCs) employed in most turbine engines is limited by delamination, both within the coating and at the coating–substrate interface. A test used for evaluating the mixed-mode toughness pertinent to such delaminations has been fully-analyzed by determining the steady-state energy release rate, the mode mixity and the critical length for buckling. An analytic solution based on beam theory establishes basic estimates and scaling relationships. Selected finite-element calculations have been used to affirm the fidelity of the results. The energy release rate attains steady-state, but the phase angle changes throughout because of a small (but significant) bending moment induced at the supports. The coating buckles at a critical delamination length, whereupon the energy release rate increases rapidly and violates steady state. The solutions are used to re-interpret measurements reported in the literature for an electron beam physically deposited TBC.