The effect of multi-planarity on the SCFs in offshore tubular KT-joints subjected to in-plane and out-of-plane bending loads

2016 ◽  
Vol 106 ◽  
pp. 148-165 ◽  
Author(s):  
Hamid Ahmadi ◽  
Esmaeil Zavvar
Keyword(s):  
Out Of Plane ◽  
Bending Loads ◽  
Plane Bending

New API RP2A Tubular Joint Strength Design Provisions

2007 ◽  
Vol 129 (3) ◽  
pp. 177-189 ◽  
Author(s):  
David Pecknold ◽  
Peter Marshall ◽  
Justin Bucknell
Keyword(s):  
Static Strength ◽  
Strength Prediction ◽  
Load Factor ◽  
Prediction Equations ◽  
Hollow Section ◽  
Out Of Plane ◽  
Bending Loads ◽  
Tubular Joint ◽  
Plane Bending ◽  
Circular Hollow Section

The development of the new API RP2A (22nd edition) parametric static strength prediction equations for planar circular hollow section tubular joints is described. Prediction equations are presented for brace axial, brace in-plane bending, and brace out-of-plane bending loads. The prediction equations are based on screened test databases, augmented, and extended by an extensive new series of validated nonlinear finite element simulations for nonoverlapping K joints, double tee (DT/X) joints, and T joints. The increased reliability (reduced scatter) provided by the new static strength formulation was used to justify a reduction of the load factor of safety to 1.6 from the previous value of 1.7.

Comparison of Failure Modes of Piping Systems With Wall Thinning Subjected to In-Plane, Out-of-Plane, and Mixed Mode Bending Under Seismic Load: An Experimental Approach

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Izumi Nakamura ◽  
Akihito Otani ◽  
Masaki Shiratori
Keyword(s):  
Dynamic Behavior ◽  
Failure Modes ◽  
Seismic Load ◽  
Piping System ◽  
Shake Table ◽  
Shake Table Tests ◽  
Wall Thinning ◽  
Piping Systems ◽  
Out Of Plane ◽  
Plane Bending

Pressurized piping systems used for an extended period may develop degradations such as wall thinning or cracks due to aging. It is important to estimate the effects of degradation on the dynamic behavior and to ascertain the failure modes and remaining strength of the piping systems with degradation through experiments and analyses to ensure the seismic safety of degraded piping systems under destructive seismic events. In order to investigate the influence of degradation on the dynamic behavior and failure modes of piping systems with local wall thinning, shake table tests using 3D piping system models were conducted. About 50% full circumferential wall thinning at elbows was considered in the test. Three types of models were used in the shake table tests. The difference of the models was the applied bending direction to the thinned-wall elbow. The bending direction considered in the tests was either of the in-plane bending, out-of-plane bending, or mixed bending of the in-plane and out-of-plane. These models were excited under the same input acceleration until failure occurred. Through these tests, the vibration characteristic and failure modes of the piping models with wall thinning under seismic load were obtained. The test results showed that the out-of-plane bending is not significant for a sound elbow, but should be considered for a thinned-wall elbow, because the life of the piping models with wall thinning subjected to out-of-plane bending may reduce significantly.

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