Abstract The relationship between microstructure, stress ratio, and fatigue fracture behavior of high-strength steel for flexible marine risers was investigated by microstructure characterization test. characteristic, S-N curve, morphology, crack morphology after quenching tempering treatment cyclic heat treatment, respectively, were evaluated. results revealed that the refined considerably, gr...

As the solidification reaches hot spot area, no molten metal remains and shrinkage is formed. To anticipate shrinkage, a riser added to casting system. An optimal design would produce free components. One of factors that affect efficiency shape. This study aims find most efficient side shape by using simulation software. The tubes, tubes with half sphere on top, hemispheres, conical an oval cro...

In recent years, the production of oil and gas has been developed in deep water depths which exceed 500m. Deep water developments are being followed strongly in different parts of the world (Caspian Sea, Gulf of Mexico, etc.). The movement of floater causes severe stress at the touchdown point (TDP) in steel catenary risers (SCR). The main objective of this study was to simulate the exact behav...

A low-dimensional model of a top-tensioned riser under excitations from vortices and time-varying tension is proposed, where the van der Pol wake oscillator used to simulate loading caused by vortex shedding. The governing partial differential equations describing fluid–structure interactions are formulated multi-mode approximations obtained using Galerkin projection method. one mode approximat...

many procedures suggest for reduction of responses of riser to vortex induced vibrations (viv). natural frequencies of marine risers is an important parameter that can affect the responses of riser to viv. change of riser properties such as top tension and bending stiffness can alter natural frequencies. in this study effects of riser specifications on the responses and fatigue damage of marine...