Failure analysis in composite plates using classical and continuum shell finite element models

The purpose of study is to examine the start of failure in composite plates . During study, Maximum Stress Failure criterion, Azzi Tsai-Hill Failure theory, Tsai- Hill Failure theory and Tsai-Wu Failure Theory have been employed. The analyses have been performed by changing thickness and angle of composite number of layer of the composite made of Hexcel G986/RTM6 with dimensions L 1 m x W 1 m and amount of load applied to composite with a hole in the center by using the classical shell model and continuum shell model.First analysis has been accomplished with the classical shell model using Abaqus program. A 1000 N/m² - static pressure load has been applied to the plate with 4 layers in orientation angles of [0/90/90/0] and it has been observed from the values obtained for 4 failure criteria that the load applied did not lead to any failure. Increasing the amount of load gradually, the amount of load where failure started to take place has been determined. Later on, the analysis has been repeated for the composite with orientation angel of [0/45/45/0]. It has been seen that the start of failure had developed at the bottom layer and varied according to the angle of orientation.During second analysis, the part has been designed to be a single-layer composite and a 1000 N/m² - static pressure load has been applied to this. Increasing the thickness of composite by 0,33mm, the analysis has been executed with the classical shell model and continuum shell model. The outcomes of the analysis have been compared. The results obtained from both modeling are similar to each other.Third analysis was performed by boring a 20 cm ? hole in the center of the composite whose mono-layer thickness was increased and applying a 1000 N/m² - static pressure load onto composite using classical shell model and continuum shell model. Failure occurred in the vicinity of hole and built-in boundary. Hole diameter was increased and the plate has undergone for the increased load failure. Failure occurred more quickly in plate with a hole closer to the edge.2012, xiv + 61 pagesKey Words: Failure analysis, composite