Static deflection analysis of flexural rectangular micro-plate using higher continuity finite-element method

In this paper, strain gradient theory is used in developing a mathematical model based on classical flexural Kirchhoff plate theory that can predict static response of rectangular micro-plates. The result of this new model is a sixth order differential equation. Order of differential terms in Galerkin weak form of the equation is reduced so that C2 hierarchical p-version finite elements with second order global smoothness can be used to solve the problem. With different boundary conditions, the computed deflection distribution of micro-plates is compared with those of the classical theory, in which length scale parameters are not present. A series of studies have revealed that when length scale parameters are considered, deflection of a rectangular plate decreases with increasing the length scale effect; in other words micro plates exhibit more rigidity than what is predicted by the classic model. Here, deflections are normalized with respect to results obtained from classical plate theory. Comparison of maximum deflection values obtained from the extended model for micro plates with those available from the classic plate model indicates that classical theory overestimates displacement values and the largest error is observed for square micro plates. The overestimation levels off for plates with aspect ratios greater than three