Compression Failure Mode of Flexible Pipe Reinforced Armor Layer with Damaged Protective Layer

A nonlinear finite element model was established to study the compressive mechanical behavior of flexible pipes and the failure mode of reinforced armor layer with the damage protective layer. First, the common damage shapes in engineering were analyzed and classified into four regular damage shapes. Then, the undamaged numerical model was analyzed. The deformation process and characteristics of tensile armor layer were elaborated. The force history curves of each layer were compared, and the impact of damage protection layer on the instability of reinforced armor layer failure was summarized. The results showed that the ability to resist radial expansion due to damage is related to the ability of the structure to withstand compression. The shape of the damage has an inducing effect on the failure mode of the reinforced armor layer. The ripple failure mode or internal dislocation of the outer sheath can instantly strengthen the reinforced armor layer and suppress circumferential buckling. Finally, the common compression failure modes of reinforced armor layers were defined, providing valuable references for failure analysis and response strategies in marine engineering.