Prediction of fracture instability in thin sheets by finite element method

A fracture instability study has been made for narrow thin panels with central cracks. The quasi-static energy approach in conjunction with finite element method has been employed for the prediction of critical crack length corresponding to a given applied stress level. The corresponding plane-stress fracture toughness, K_Ic has been shown to differ considerably with regard to that obtained from tests following the standard practice. However, the plane stress fracture toughness value obtained experimentally based on the predicted critical crack length is found to be in close agreement with the theoretically obtained value.