RESEARCH ON TENSILE PERFORMANCE OF HELICAL CARCASS COMPOSITE FLEXIBLE CRYOGENIC PIPE FOR LNG

Helical carcass composite flexible cryogenic pipe for LNG（HCFP） is a typical multi-layer, multi-material, non-adhesive composite structure that is helically wound. The structural analysis of HCFP presents substantial challenges, owing to large geometric deformations, extreme cryogenic temperature, and intricate interlayer contacts. These factors render traditional theoretical models for tensile performance inadequate. Here, a comprehensive empirical investigation was conducted to assess the tensile performance of a 12-inch diameter HCFP, under both ambient and cryogenic temperature conditions. Subsequently, an intricate numerical model of HCFP was systematically developed, drawing upon empirical and measurement data. A subsequent sensitivity analysis was undertaken, focusing on critical dimensional parameters, so as to elucidate their profound influence on the tensile performance of the pipe. A substantial enhancement of 12.69% in tensile resistance under cryogenic conditions was found. Furthermore, increasing the helical pitch of the support layer by 50% yielded a remarkable 52.36% reduction in tensile resistance. This research provides invaluable reference and enable informed decisions for the design and optimization decisions of HCFP within this specialized domain.