A review of the CTOA/CTOD fracture criterion

摘要: Abstract The crack-tip-opening angle or displacement (CTOA/CTOD) fracture criterion is one of the oldest criteria applied to metallic materials with cracks. During past two decades, use elastic–plastic finite-element analyses simulate laboratory specimens and structural components using CTOA has expanded rapidly. But early applications were restricted two-dimensional analyses, assuming either plane-stress plane-strain behavior, which lead generally non-constant values CTOA, especially in stages crack extension. Later, traced inappropriate state-of-stress (or constraint) assumptions crack-front region severe tunneling thin-sheet materials. More recently, been used three-dimensional study constraint effects, tunneling, process. constant (from initiation failure) successfully numerous applications, such as aircraft fuselages pipelines. why does “constant CTOA” work so well? This paper reviews results from several studies, discusses issues works, its limitations.