ANALYSIS ON CREEP DEFORMATION OF DEEP-SEA FULLY-TRANSPARENT PRESSURE-RESISTANT HULL

Polymethyl methacrylate (PMMA) is a kind of transparent polymer compound with good transparency, corrosion resistance, light weight, and excellent mechanical strength, which can be the candidate fully-transparent pressure-resistant hull material of submersibles. PMMA is a viscoelastic material, and when subjected to prolonged external high pressure, the pressure-resistant structure made of PMMA may undergo creep deformation, resulting in a decrease in its load-bearing capacity. In the present study, finite element analyses on the PMMA pressure-resistance hulls are conducted aiming at obtaining the creep deformation based on temperature-dependent time-hardening creep model from a series material tests. The creep properties of different types of spherical hulls without or with large openings are studied. And the strain-time curves and displacement curves of PMMA pressure-resistant hulls under varying pressures and temperatures are analyzed. The analysis results will provide reference for design of full-transparent manned cabin in deep-sea submersibles.