Residual strength prediction of damaged composite fuselage panel with R-curve method

This study applies the crack growth resistance curve (R-curve) method to predict the residual strength of a composite fuselage panel with discrete source damage. The R-curve is constructed from the energy release rates computed from cracked tensile plate test specimens at their failure loads. To predict the residual strength of a curved fuselage panel with discrete source damage using the R-curve method, G-curves of the energy release rate of the damaged fuselage panel need to be established. These G-curves are generated for various fuselage pressures over a range of crack lengths. Since this study found that the membrane stiffening effect could significantly reduce the energy release rate at the crack tip of a pressurized fuselage, geometrically nonlinear behavior was considered in the calculations. The residual strength of the damaged fuselage panel was determined by comparing the energy release rates with the “allowable-like” R-curve. The correlation between the crack growth predictions and the damage progression results obtained from experiments is very good. Therefore, the R-curve method has the potential to be a practical engineering method for predicting the residual strength of damaged fuselage panels.