... by assuming Mmax = Mp and = t/D2. The effect of ny is very small for tubes without internal or external pressure and soil loads. The effect of ovalisation (reduction of the section modulus) and plate bending moments on the bending moment curvature diagram is depicted in Fig. 4. CRITICAL CURVATURE FOR LOCAL...

... analytical methods in the riser design processes. arc length stress histogram study result flexible riser pressure distribution hysteresis curve stiffness comparative study result upstream oil & gas global time domain analysis critical curvature normal stress curvature nonlinear...

..., the sensitivity analysis is also carried out to examine the influence of various design parameters, such as critical curvature, slip stiffness and etc. The purpose of this research is to tentatively propose new assessment procedures to standardize the dynamic response analysis of flexible pipes in offshore...

... and numerical simulations. The results of this research project are also relevant for strain-based pipeline design, where more emphasis is on the critical curvature. INTRODUCTION Spiral-welded steel tubes are often employed in combined wall systems, e.g. for quay wall systems as indicated in Fig. 1...

..., they are a flexible structure made up of different component layers and their main mechanical characteristic is that they are axially and torsionally stiff while being compliant when bent. This flexibility is achieved thanks to the fact that inner layers can slide one over another after a critical curvature...

... umbilicals. The critical curvature at which the helix components slip fully against the supporting layers is another important factor which has direct impact on the fatigue assessment. In addition to these two factors, the direct input entering into fatigue calculation will be the stress amplitude for any...

... expression witz friction tendon neutral axis internal pressure friction coefficient curvature cross-section inch flexible pipe critical curvature stiffness magnitude helical layer cable Proceedings of the Ninth (1999) International Offshore and Polar Engineering Conference Brest, France, May...

... and bending loads. The sensitivities of collapse moment and critical curvature under pure bending to diameter to thickness ratio DJt, yield parameter to Young's modulus ratio CJ/E, strain-hardening parameter n and material anisotropy parameter S are investigated, using an experimentally validated finite...