Proceedings, Volumes 1-2

aluminium alloy APPENDIX applied stress behaviour bending brittle constant crack extension crack front Crack Growth Rate Crack lengths read crack propagation crack tip creep critical crack length Cycles Crack Cycles Number cylinder dislocations ductile effect elastic energy equation failing stress failure fatigue crack fatigue limit flat sheet fracture surface gross area stress hole increase kpsi Lnth load material maximum mechanism metals mild steel nickel nitrogen notch number of cycles observed obtained occur panels plane strain plane stress plastic deformation plastic zone plate pounds and dimensions psi max radius rate of crack ratio region residual strength restrained from buckling rivet Room Temperature rupture S-N curve shear lip shear stress shown in Fig shows slip SNET Spec stage static stiffener strain aging stress concentration stress cycle stress intensity factor stress level striations stringers structure tensile stress tension thickness unstable vacuum width yield