Prediction of principal stresses and strains in laminated composites using MATLAB

Abstract The present study deals with laminated composite plate modeling and analysis. Major research in the field of composite structures has been carried out in recent years due to its widespread use in aerospace as smart and even some intelligent structures. In the current analysis, classical laminated plate theory is considered for studying the failure criteria of composites, by creating MATLAB script files which assist the operator to work under safe conditions of composite laminates design. MATLAB is an ideally suited programming tool to study the mechanics of composite materials because the formulation of the mechanical behaviour of composite materials involves extensive use of matrices. The input sources required to execute the conventional based program are the properties of the material its limits, and applied load. To calculate the principal stresses and strains on each layer for two-dimensional composites, equations considering Hooke's Law were used. Via the failure theory known as Tsai-Wu failure theory, failure analysis of the framework was carried out. According to Tsai-Wu failure criterion, the laminate will fail under transverse loading σ2 and the failure occurred at layer 2 at a stress of 3.66 MPa. Under compression loading, failure occurred either on 2nd layer or 4th layer with transverse compressive stress of 25 MPa. To prevent the failure of the composite laminate the Strength Ratio obtained should lie between the range of 1 to 1.2 so it is required to change the orientation of fiber layer and also add on the optimal number of fiber layers.