Numerical Analysis of Flat Panel Composite Material for Two-Bay Crack Arrest Competency with Fractured Central Longeron

A phenomenon that might cause a structure to collapse catastrophically is the propagation of cracks inside composite materials or at the interface of composite joints. Fail-safe design becomes essential when a structure's integrity is compromised by the element of safety because it has measures that limit failure. This work summarises the research that has been done on these types of crack-arresting features, or CAFs, for metal, composite, and composite laminate joints. Large fatigue cracks are intended to be tolerated in wide-bodied aircraft, and the general damage tolerance design includes two-bay crack arrest capability. In these aircrafts, longeron failure at fuselage crown leads to development of circumferential cracks in the pressurised cabin. The longeron’s capacity to accept load transfer from the cracked skin is what causes these skin cracks to be arrested for two-bay long crack. In direction to create effective damage-tolerant configuration, several parametric studies were carried out, with the longeron being crucial to the safety of circumferential cracks. Using finite element method (FEM) analysis method, the geometry for longeron was assessed, and it was discovered that Z-Stiffener with larger cross section was more successful in stopping cracks.