Enhanced and weakened strength in brittle film-substrate structure

摘要: Abstract The mechanical properties of multi-use multilayers including the apparent tensile strength are important for estimating multilayer's reliability. Yet in biaxial flexure, there exist enhanced or weakened performances when measuring laminates, resembling those found uniaxial load. In this paper, a model is proposed to predict effect thin film on terms applied Six cases discussed characterize laminated membranes by introducing Apparent Strength Enhancement Factor (ASEF). It notable that ASEF independent from thermal residual stresses case where substrate can continue sustain entire external load solely cracks first. Experimental results show clearly fracture stress half-cell lower than corresponding anode substrate. prediction capability has been validated experimental results, though additional experiments still required order critically assess model's predictions over range bilayer laminates. addition, comparison reverse between different types loading reveals present analysis significative design and discussion integrity multilayers.