Elastic Constants Identification of Shear Deformable Laminated Composite Plates

A constrained minimization method is presented for the identification of elastic constants of shear deformable laminated composite plates. Strains and or displacements obtained from static testing of laminated composite plates are used in the proposed method to identify the elastic constants of the plates. In the identification process, the trial elastic constants of a laminated composite plate are used in a finite-element analysis to predict the strains and displacements of the plate. An error function is established to measure the differences between the experimental and theoretical predictions of strains and or displacements. A constrained minimization technique is used to minimize the error function and update the trial elastic constants. The best estimates of the elastic constants of the plate are then determined by subsequently reducing the size of the feasible region of the elastic constants and making the error function a global minimum. The accuracy and applications of the proposed method are demonstrated by means of a number of examples. A sensitivity analysis is also performed to study the effects of variations of experimental data on the accuracy of the identified elastic constants.