The modified Brazier approach to predict the collapse load of a stiffened circular composite spar under bending load

The response of a stiffened circular composite spar subjected to bending was studied analytically using a modified Brazier approach. The spar caps were placed in the top and bottom sectors of a spar to increase the bending capabilities such as the rigidity and collapse load. The mathematical model to predict the collapse load of the stiffened circular spar was derived using the linear elastic energy method. Numerical simulations were performed to estimate the effect of the spar caps on the failure load and compared with the presented model. A static experimental test was performed on a prototype stiffened spar, and the test results were compared with a mathematical model. The results show that the modified Brazier approach can reasonably predict the collapse load.