Structural Behavior of Umbilicals: Part II—Model-Experimental Comparisons

Author(s):  
Celso Pupo Pesce ◽  
Andre´ Lui´s Condino Fujarra ◽  
Marcos Rabelo ◽  
Rafael Loureiro Tanaka ◽  
Clo´vis de Arruda Martins ◽  
...  

A set of tests was performed in a non-armored Steel Tube Umbilical (STU), including pure pressure loading, constant and variable tension loads and combinations of constant and cyclic bending moment and tension. Tests were made for pressurized and non pressurized conditions. Strains were measured with strain gages attached to the external surface of selected tubes. Instrumentation was performed in four windows that were opened on the umbilical outer sheath to provide access to the tubes. Besides the strains, tension, internal pressure and imposed angle were measured. Comparisons with results obtained using the model presented in Part I, [1], are presented for different load conditions.

2020 ◽  
Vol 214 ◽  
pp. 110655
Author(s):  
Peijun Wang ◽  
Lele Sun ◽  
Mei Liu ◽  
Boxun Zhang ◽  
Xianfeng Hu ◽  
...  

Author(s):  
Xiaoxue An ◽  
Alan Dobson ◽  
Chun Yip Chan

Super Duplex Stainless Steel (SDSS) tube is the main component in steel tube umbilicals for the transportation of hydraulic fluids and chemicals, or gas injection into the subsea well. The umbilical tube is made from seamless tube joined together by girth weld. Therefore, porosity is one of the main weld defects that could be discovered within the welds, and these defects can have significant impact on the execution of the whole project, in term of both schedule and cost. This paper reviews the design codes and standards relating to the porosity acceptance criteria, and discusses the recent investigation on the influences of porosity (number, size and location) to the stress distribution within the weld. The study was performed using both FEA and practical fatigue test. The results demonstrated that the distance of the pores to the weld surface is a critical parameter to the increase and localisation of stress as the pore starts to interact with the weld root or cap. In addition, significant pore stress interaction has been observed when a bending moment is introduced to the weld. The study has demonstrated that the current porosity acceptance criteria applied to umbilical manufacture in the subsea industry are typically conservative and can be modified.


2010 ◽  
Vol 452-453 ◽  
pp. 485-488 ◽  
Author(s):  
Peng Niu ◽  
Gang Yang ◽  
Chun Fu Jin ◽  
Yi Xiong Wu

Based on Ježek method of computing the elastic-plastic buckling of the member under the axial compressive load and the bending moment, the analytical expressions of calculating the ultimate load of buckling about the neutral axis with the moment of inertia for a square steel tube column are derived. By degenerated into the analytical expressions of the rectangular column and compared with the values of the finite element analysis (FEA) method, it shows that the analytical method in this paper is valid, which provides a new method of theoretical study for the elastic-plastic buckling of the member.


Author(s):  
Satoshi Nagata ◽  
Toshiyuki Sawa ◽  
Takashi Kobayashi ◽  
Hirokazu Tsuji

This paper reports the results of finite element analysis representing the sealing performance tests on the slip-on type pipe flange connections for 8 inch and 16 inch. The flange connections are subjected to internal pressure and bending moment. Internal pressure is applied by helium gas and the bending moment is loaded through 4 points bending equipment. Gas leak rates are measured by pressure decay method. During the test, the variations in the axial bolt force are monitored for all the bolts by strain gages. The pipe stress at the junction of pipe and flange is also measured. Finite element analysis simulates the tests and the simulated results are compared with the measured data. Then the behaviors of the slip-on type flange connections under internal pressure and bending moment as well as the sealing performance are clarified by the experiment and the finite element simulation.


2020 ◽  
Vol 15 (55) ◽  
pp. 345-359
Author(s):  
Nourddine Hammadi ◽  
Moahmed Mokhtari ◽  
Habib Benzaama ◽  
Kouider Madani ◽  
Abdelkader Brakna ◽  
...  

The pipes, during their service, are subjected to accumulated loads such as internal pressure and that of the soil. The latter considerably accelerate their damage. In this work, the bending moment stress of API 5L X70 category steel elbows under thermo-mechanical behavior and in the presence of pressure were studied. We used FEM (finite element method) through the numerical calculation code ABAQUS and the XFEM technique for structural damage while using solid elements as a structure. Our objective is to evaluate the response and resistance capacity of the steel elbow by its location in the tube–elbow-tube system under a mixed loading of pressure and moment for all scenarios. It is based on a single standardized dimensioning of the elbow (diameter and thickness). The effect of several parameters has been studied such as the type of loading and the pressure levels, which are clearly conditioned by the level of damage. Numerical damage results are presented by moment-rotation curves. They illustrate the variation in damage as a function of these effects which act simultaneously.


2021 ◽  
Vol 11 (20) ◽  
pp. 9469
Author(s):  
Xiaojuan Li ◽  
Guoliang Dai ◽  
Xueying Yang ◽  
Qian Yin ◽  
Wenbo Zhu ◽  
...  

Few studies, especially those related to field tests, have examined the bending behaviors of drilled shafts with partial casings (DSPCs). This work reports the results of experimental studies on the behavior of DSPCs under lateral loads, including an in situ test and a set of laboratory tests. First, a DSPC with a diameter of 2 m and length of 87.9 m was studied in clay beds, and a steel casing with a diameter of 2.0 m and length of 33 m was used. In this test, strain gauges were distributed along the steel rebars in the concrete pile and the wall of the steel tube at different depths, and thus the longitudinal strains of the concrete pile and the steel tube could be studied. Second, laboratory experiments were implemented with reinforced concrete-filled steel tubular columns under pure bending conditions. In these tests, strain gauges were distributed along the steel rebars in the concrete pile and the walls of the steel tubes at the pure bending section of the specimens. Different wall thicknesses and drilling fluid conditions were considered. The field test results show that the strain of the concrete piles and the steel tubes were linearly distributed at the same cross-section. This means that a DSPC remains a flat plane after it deforms. Whereas a correction coefficient related to the loading level need to be considered in the calculation of the bending stiffness. Laboratory studies show that the strain of DSPCs was linearly distributed at a small bending moment under the best bond-quality condition, whereas obvious nonlinear behaviors were shown under a large bending moment with poor bond-quality conditions.


2020 ◽  
Vol 5 (11) ◽  
pp. 1307-1318
Author(s):  
Ovundah King Wofuru-Nyenke

In this paper, an efficient, affordable, and portable manual automobile tyre changing tool was designed. The tool operates on the principle of second-class levers, where the load to be overcome is situated between the fulcrum and the effort point. The mechanical advantage (MA) of the bead breaker arm and pry bar assembly of the tool was determined to be 11.5. The standard tube size of the bead breaker arm that can withstand stress due to bending moment was determined to be a 2” (50mm) diameter Schedule 80 steel tube. Also, the dimensions of the standard hexagonal bolts to be used at the fulcrum and load point of the bead breaker arm are M12 × 1.5 × 75 mm, while the standard size of hexagonal nuts to be used with the bolts is M12 × 1.5 mm with a height of 10mm. Moreover, the mechanical advantage (MA) of the mount/demount arm and pry bar assembly of the tool was determined to be 5.22. Also, by comparing the angles of twist of two sizes of the mount/demount arm when the tool is used in mounting or demounting a tyre on a 16” × 7” wheel rim, the standard size of the mount/demount arm that can withstand stresses due to bending moment and torsional moment was determined to be a 60mm × 60mm × 5mm square tube. The cost of materials needed to fabricate the tyre changer summed up to ₦21,000. Ergo, the design provides an alternative portable and relatively affordable tyre changing tool that can be afforded by tyre technicians across Nigeria, and other developing or underdeveloped countries.


2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Xuesong Zhang ◽  
Ningyi Liang ◽  
Xiaohong Lu ◽  
Anbang Gu ◽  
Jidong Shan

With the continuous construction of 500 m concrete-filled steel-tube (CFST) arch bridges such as the Bosideng Yangtze River Bridge and the Hejiang Changjiang Highway Bridge, the deviation between the dead pressure line and the arch axis produced by extant arch axis optimization methods increases. Therefore, an arch axis optimization method for long-span CFST arch bridges with a truss section must be designed. Following the optimization of the truss arch axis, this study develops the minimum section eccentricity method that aims to optimize the arch axis of long-span CFST arch bridges. To minimize the main tube eccentricity of the truss arch, the bending moment of the main tubes is reduced by applying the main tube eccentricity method iteratively in a finite element model. Afterward, a smooth and reasonable arch axis is fitted by applying a cubic spline interpolation function in MATLAB. The entire optimization procedure is performed using the Bosideng Yangtze River Bridge as an example. Compared with that of optimal arch axis line types (e.g., parabola and catenary) and other traditional arch axes, the bending moment of main tubes optimized by the proposed method is substantially lower and more uniformly distributed along the arch axis span. The mechanical properties of the finished bridge, including its strength, stiffness, and stability, are all improved, thereby verifying the feasibility of using the proposed method to optimize the arch axis of CFST arch bridges with a truss section.


1981 ◽  
Vol 18 (03) ◽  
pp. 276-284
Author(s):  
Albert W. Forrest ◽  
Richard F. Labasky

A detailed description of the strain-gage shaft alignment procedure is presented, including a comparison between bearing reactions obtained using strain gages and hydraulic jacking. The various gage configurations available for measuring bending moments are discussed and estimates of the resulting error in bending moment are given. A simplified procedure is presented to calculate bearing reactions from the measured moments. Gage site requirements to produce a determinate system are established and a method is outlined to establish bearing reaction error bounds for a combination of gage configurations and sites.


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