Effect of matrix and fibre cracks on static and fatigue strength of composite laminates

The effect of matrix and fibre cracks on the static strength and stiffness of uni-directional plies and cross-ply laminates under tensile loads was examined with the goal of understanding the main damage mechanisms. The size of matrix cracks emanating from cracked fibres was determined and found to be in excellent agreement with test results....

Design and testing of aeroelastically tailored composite wing under fatigue and gust loading including effect of fatigue on aeroelastic performance

The aim of the paper is to experimentally validate a numerical design methodology for optimizing composite wings subject to gust and fatigue loading requirements and to assess the effect of fatigue on the aeroelastic performance of the wing. Traditionally, to account for fatigue in composite design, a knockdown factor on the maximum stress...

Aeroelastic optimization of composite wings including fatigue loading requirements

An analytical model to predict the fatigue life of a composite laminate is formulated. The model calculates stresses in each ply using classical lamination theory, degrades the residual strength using the linear wear-out law and predicts failure based on Tsai Wu failure theory. The cycles to failure are predicted using the updated cycle-by...

Predicting the Structural Performance of Composite Structures Under Cyclic Loading

The increased use of advanced composite materials on primary aircraft structure has brought back to the forefront the question of how such structures perform under repeated loading. In particular, when damage or other stress risers are present, tests have shown that the load to cause failure after a given number of cycles is a decreasing...