This study is presenting a non-local closed-form solution for interfacial stress/strain and the warpage deformation for thin trilayer plate structures under thermal cycling.
Based on the theory of geometric scale dependency of the material behavior, the material properties of a thin multi-layer inter-bonded structures substantially differ from those determined based on the bulk material samples. Hence the real mechanical properties for such thin layers are often unavailable and difficult to obtain.
This paper puts forward a method to provide a solution for thermomechanical behavior of trilayer constituents with high accuracy at real scale. Present study demonstrates that the constitutive behavior of multilayer plate’s constituents can be inversely determined so long as the plate’s global deformation can be made available by measurement.
To achieve most accurate determination of the material properties, measurements with high accuracy is required. The paper also presents the advanced method of shadow moiré that have applied to obtain warpage deformation of real life trilayer test specimens under thermal cycling.
Using this method, the experimentally determined global deformation (warpage) of a trilayer structure were correlated with the analytical model solved for warpage deformation. The correlation was then progressively optimized to result in material properties of the constituents. The bonding layer properties are called determined, once the correlation reaches over 85%.
There exist a variety of different multilayer bonded structures, which are usually made with advanced manufacturing processes. Regardless of design layout and materials constitutive relations, the application can be implemented in characterizing multiply stacked trilayer structures.