Impact Response of Polyurea Elastomer Coated Cylindrical Shell Composite Structures Subjected to Repeated Blast Loads

To improve the anti-repeated blast performance of oil and gas transportation pipelines, the damage characteristics and polyurea protection performance of spray polyurea coated steel pipes under lateral repeated blast loads were investigated. The results demonstrate that 1−6 mm thick polyurea coatings effectively reduced maximum mid-span deflection by 21.7%−43.5% under single blast; for repeated blast, the presence of polyurea could limit and prevent cracking of steel pipes. A repeated blast simulation model was developed by LS-DYNA explicit dynamics software, with validation achieved through quantitative comparison of macro-failure patterns and deflection measurements. The energy propagation law inside the polyurea coated steel pipe was analyzed through numerical models, and it was found that polyurea can effectively reduce the internal energy and kinetic energy absorbed by the steel pipe, protecting its integrity.