APPROXIMATE SOLUTIONS FOR STRESSES AROUND PIN-LOADED HOLES IN SYMMETRICAL COMPOSITE LAMINATES

The knowledge of average in-plane stress field in the vicinity of the pin-loaded holes is essential for predicting both the failure strength and edge effects of composite laminate pinned joints. In this paper, a simplified technique is proposed to approximately determine the dist ribution of in-plane stresses in pin-loaded composite laminates based on the values of stresses right at the pin-loaded hole edges using the Reissner variational principle. The research results show that the di stribution of stresses can be represented in the forms of Dower formul a or exponential formula. and the corresponding numerical results are in good agreement with the available experimental data.