On propagation of interface cracks parallel to free boundaries in relation to delamination of multilayered coatings
The problem of a crack propagation in multilayered coating either between the individual layers,or between the whole package forming the coating and substrate (possibly also non-uniform) is considered.According to the model the delaminated part of the coating is treated as a plate with a special attention given to the boundary conditions,which are supposed to be of the elastic clamping type,which means that the angle of rotation at the clamping point is related to the acting bending moment at that point.The generalized model of elastic clamping is also considered in the frame of which it is supposed that components of displacements and angle of rotation at the clamping point are related to the acting total force and total moment by means of 3x3 matrix of elastic coefficients.Several variants of analytical models to determine the coefficients of this 3x3 matrix were considered and discussed.The case of non-uniform (multi-layered) coating is considered with a special attention paid to analysis of the influence of the relative dimensions involved,such as the individual layer and the multilayer coating thicknesses,distance from the crack to the free surface,crack length.Using the obtained solution the problem on buckling of the delaminated coatings is addressed.It has been shown that for a wide range of parameters even for anisotropic and multilayered structures the ratio of the obtained critical stress and the critical stress of a rigidly clamped plate is determined by a single nondimensional parameter,which is a combination of the elastic constants of the coating and substrate,and the ratio of the delamination length to the coating thickness.The analytical results correlate well with the results obtained using the numerical calculations.
Interface crack Multilayered coatings Delamination Elastic clamping Buckling
Konstantin B. Ustinov Robert Goldstein
IPMech RAS,119526,Russia
国际会议
北京
英文
1-9
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）