...José Renato M. de Sousa; Paula F. Viero; Carlos Magluta; Ney Roitman This paper deals with a nonlinear three-dimensional finite element (FE) model capable of predicting the mechanical response of flexible pipes subjected to axisymmetric loads focusing on their axial compression response. Moreover...

...Alfredo Gay Neto; Clóvis de Arruda Martins When there is a failure on the external sheath of a flexible pipe, a high value of hydrostatic pressure is transferred to its internal plastic layer and consequently to its interlocked carcass, leading to the possibility of collapse. The design...

...Bala Padmanabhan; R. Cengiz Ertekin It has been proposed that the warm surface-water intake pipes distributed around an OTEC plant can generate adequate momentum to globally position a platform to overcome the second-order drift forces, thereby eliminating the need for additional power...

...Hugo A. Ernst; Richard E. Bravo This work studies the effect of the yield ( Y ) to tensile ( T ) ratio, Y ∕ T , on the structural integrity of line pipes with part through the thickness (PTT) circumferential defects subject to bend loading. A model based on elastic-plastic fracture mechanics...

... materials studied, different cases with different Y ∕ T values were considered. Even for the lower limits of experimental data, i.e., larger Y ∕ T , the materials have adequate defect tolerance. line pipe fracture mechanics plastic collapse structural integrity internal pressure The objective...

... by the optimizer to find the best solution. Restricting the analysis to a free-hanging or a lazy-wave steel riser, compounded by three pipe segments with equal diameters and thicknesses and a floater in the middle segment with a given buoyancy per unit volume, the design variables are the lengths of the segments...

... in this type of pipes. For this purpose, two-equation turbulence models ( k − ϵ and k − ω ) are used in the computations. First, the fully developed turbulent flow in a conventional pipe is considered. Simulations are performed to validate the chosen models, boundary conditions, and computational grids...

... on these pipelines, resulting in localized wrinkles well into the plastic range of the pipe material. Eventually, there is a possibility of a fracture occurring at a wrinkled location under continuous deformation. A recent field fracture and a failed laboratory specimen have been observed within a telescopic wrinkle...

.... It is clearly not possible to determine the pipe response experimentally for all possible time histories of curvature magnitude and direction. Therefore, the Orcina bending hysteresis model uses the basic nonlinear curve A to C and uses it to calculate the bending moment history that results from...

...Ralf Peek; Heedo Yun Analytical solutions for the lateral buckling of pipelines exist for the case when the pipe material remains in the linearly elastic range. However for truly high temperatures and/or heavier flowlines, plastic deformation cannot be excluded. One then has to resort to finite...

...Mir Emad Mousavi; Abbas Yeganeh Bakhtiary; Nastaran Enshaei Physical experiments have been conducted to study the scouring around a pipe over an erodible bed under wave motion. The results show that the depth of the wave-induced scour is reduced when the pipe is installed in a primary depth...

... Fig. 3 5 Georgiadis ( 10 )—1991 Drag forces exertedon pipes moving in theclay mass F D , 90 = Q r ⋅ ( U U r ) n for U ⩽ 2 × 10 − 3 m ∕ s ( 120 mm ∕ min ) Q r = 2.19 kN ∕ m , U r = 1.7 10 − 5...

... Andronicou. Serta , O. B. , and Brack , M. , 1990 , “ Stress and Strain Assessment of Multi-Layer Flexible Pipes ,” Proceedings of the First European Offshore Mechanics Symposium , Norway , pp. 442 – 448 . Feret , J. J. , and Bournazel , C. L. , 1987 , “ Calculation...

...Xu Hailiang It is known from the principle that the pump–vessel combined ore lifting method has high head, large ores lifting capacity, and long-term working reliability. When applied to the deep-sea rigid pipe mining system, the main pump and power equipment installed on the mining ship is more...

...Hiroyuki Motohashi; Naoto Hagiwara By conducting curved wide plate tensile tests for girth welded joints of X80 line pipe containing a surface notch in the weld metal, the effects of strength matching on fracture performance were evaluated. Parametric studies were also conducted using a finite...

... on API 5L X60 and X80 grade line pipes. The tensile tests revealed that the tensile properties of the cold bends were comparable to the uniaxially prestrained specimens machined from the straight part of the pipes. A FE model simulating the cold bending process was verified with the full-scale...

... model without needing to know the nature and details of the reinforcement. couplings design engineering pipes modal analysis beams (structures) generic parametric equation welded structure tubular joint hot spot stress doubler plate reinforced stress concentration fatigue life...

...-dimensional pipe/soil interaction problem is modeled using nonlinear soil springs and special beam elements using the finite element method to estimate pipe response for statistically possible ranges of gouge depths, gouge widths, and burial depths. Relevant failure mechanisms have been considered, including...

...John M. Sheehan; Frank W. Grealish; Annette M. Harte; Russell J. Smith As the offshore industry moves towards deeper water developments and continues to embrace harsh environments, unbonded flexible pipes are increasingly being utilized as a cost effective riser solution. Furthermore...

... of initial imperfections on the behavior of segments of line pipe. Imperfections measured across the inside surface of pipe test specimens were incorporated into a finite element model that was developed to predict the experimental behavior of the specimens tested under combined loads of internal pressure...