Based on the Upper Bound Theory, a Simplified Engineering Approach is Presented to Determine the Ultimate Strength of a pin-Loaded Composite Laminate in this Papaer. According to the Upper Bound Theory, the Displacement Rate in a Given Ply is Divided into Two Zones: the Moving Zone and the Static Zone. the Applied Load Q that Associated with Displacement must be Less than the Maximum Resistance of the Laminate. in this Paper we have Discussed the Failure Region, Failure Type of each Ply and Simplified the Tsai-Wu Failure Criterion. Experiments of Single-Bolt Double-Lap Joints have been Conduncted According to ASTM D5961 Test Standard. Finally, we can Observe that the Engineering Approach is in Good Agreement with the Test Results.
