Failure Modes of American Petroleum Institute 12F Tanks With a Rectangular Cleanout and Stepped Shell Design

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Eyas Azzuni ◽  
Sukru Guzey
Keyword(s):  
Internal Pressure ◽  
Stress Analysis ◽  
Failure Modes ◽  
American Petroleum Institute ◽  
Buckling Analysis ◽  
Vacuum Pressure ◽  
Maximum Pressure ◽  
Elastic Buckling ◽  
Shell Design ◽  
Nonlinear Geometry

The design and fabrication of shop-welded and prefabricated relatively small tanks, when compared to field-welded tanks, used in the upstream segment of the oil and gas industry is governed by the American Petroleum Institute specification 12F (API 12F). This study explores the changing designs of API 12F tanks to include a new rectangular cleanout design with reinforcement as shell extension internally of cleanout frame and a stepped shell design. This study also investigated the introduction of two additional tank sizes in addition to existing eleven tank sizes in the current 12th edition of API 12F. The adequacy of the new design changes and proposed tank designs were verified by elastic stress analysis with nonlinear geometry, elastic–plastic stress analysis with nonlinear geometry, and elastic buckling analysis to verify their ability to operate at a design internal pressure of 16 oz/in2 (6.9 kPa) and maximum pressure during emergency venting of 24 oz/in2 (10.3 kPa). A vacuum pressure of 1.5 oz/in2 (0.43 kPa) was also investigated using the elastic buckling analysis. The stress levels and uplift of the tanks are reported in this report to provide insights into the behavior of proposed API 12F tanks exposed to higher internal pressure and vacuum pressure.

Experimental Demonstration of Failure Modes on Bellows Structures Subject to Internal Pressure

2017 ◽  
Author(s):  
Masanori Ando ◽  
Hiroki Yada ◽  
Kazuyuki Tsukimori ◽  
Masakazu Ichimiya ◽  
Yoshinari Anoda
Keyword(s):  
Internal Pressure ◽  
Evaluation Method ◽  
Failure Modes ◽  
Difficult Problem ◽  
Maximum Pressure ◽  
Test Results ◽  
Element Analysis ◽  
Complex Deformation ◽  
Explicit Analysis ◽  
Pressure Failure

In this study, in order to develop the evaluation method of the pressure toughness of bellows structures under the beyond design base event, the pressure failure tests and finite element analysis (FEA) of the bellows structures subjected to internal pressure were performed. Since the several tests and FEA results were reported previously by current authors, the additional tests were performed by the specimen simulating the real setting situation in the actual plant and for demonstrating the plain failure modes. Test specimens consist of the single and double ply bellows made of SUS304 were used. Total five specimens were tested, and one specimen was attached the guard pipe around the bellows to simulate the actual situation in the plant to confirm the effect of the neighbor structures to the ultimate toughness. The maximum pressure obtained in all tests were over 10 times larger than the estimated results of limiting design pressure based on in-plain instability by the EJMA standards; although the test specimens were pressurized exceed the pressure of buckling deformation. Because it is very difficult problem to simulate the inversion of the convolution accompanied convolutions contact for FEA with implicit method, FEA with simplified technique and explicit analysis were performed to simulating the complex deformation of the test specimen, and then these results were estimated in some procedures to compare with the test results. Three failure modes identified in the tests, however, the complex deformation behavior make it difficult to simulate by ordinary FEA procedure and to estimate the ultimate toughness of the bellows structures under the internal pressure. Therefore several kinds of idea for evaluating the ultimate toughness of the bellows structures were execute and suggested.

Stress Analysis of Tire Sections

1996 ◽  
Vol 24 (4) ◽  
pp. 349-366 ◽  
Author(s):  
T-M. Wang ◽  
I. M. Daniel ◽  
K. Huang
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Stress Analysis ◽  
Strain Analysis ◽  
Experimental Stress ◽  
Inflation Pressure ◽  
Substantial Agreement ◽  
Finite Element Stress Analysis ◽  
Strain Components ◽  
Fringe Patterns

Abstract An experimental stress-strain analysis by means of the Moiré method was conducted in the area of the tread and belt regions of tire sections. A special loading fixture was designed to support the tire section and load it in a manner simulating service loading and allowing for Moiré measurements. The specimen was loaded by imposing a uniform fixed deflection on the tread surface and increasing the internal pressure in steps. Moiré fringe patterns were recorded and analyzed to obtain strain components at various locations of interest. Maximum strains in the range of 1–7% were determined for an effective inflation pressure of 690 kPa (100 psi). These results were in substantial agreement with results obtained by a finite element stress analysis.

Post-Buckling Failure Modes of X65 Steel Pipe: An Experimental and Numerical Study

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Nima Mohajer Rahbari ◽  
Mengying Xia ◽  
Xiaoben Liu ◽  
J. J. Roger Cheng ◽  
Millan Sen ◽  
...  
Keyword(s):  
Internal Pressure ◽  
Cross Section ◽  
Failure Modes ◽  
Bending Test ◽  
Bending Load ◽  
Post Buckling ◽  
X65 Steel ◽  
Bending Loads ◽  
Buckling Failure ◽  
Longitudinal Strains

In service pipelines exhibit bending loads in a variety of in-field situation. These bending loads can induce large longitudinal strains, which may trigger local buckling on the pipe's compressive side and/or lead to rupture of the pipe's tensile side. In this article, the post-buckling failure modes of pressurized X65 steel pipelines under monotonic bending loading conditions are studied via both experimental and numerical investigations. Through the performed full-scale bending test, it is shown that the post-buckling rupture is only plausible to occur in the pipe wall on the tensile side of the wrinkled cross section under the increased bending. Based on the experimental results, a finite element (FE)-based numerical model with a calibrated cumulative fracture criterion was proposed to conduct a parametric analysis on the effects of the internal pressure on the pipe's failure modes. The results show that the internal pressure is the most crucial variable that controls the ultimate failure mode of a wrinkled pipeline under monotonic bending load. And the post-buckling rupture of the tensile wall can only be reached in highly pressurized pipes (hoop stress no less than 70% SMYS for the investigated X65 pipe). That is, no postwrinkling rupture is likely to happen below a certain critical internal pressure even after an abrupt distortion of the wrinkled wall on the compressive side of the cross section.

Failure Analysis of Tubular Hydroforming

2000 ◽  
Author(s):  
Z. C. Xia
Keyword(s):  
Internal Pressure ◽  
Process Parameters ◽  
Deformation Theory ◽  
Failure Modes ◽  
Tensile Loading ◽  
Failure Criteria ◽  
Material Anisotropy ◽  
Governing Equations ◽  
Compression Load ◽  
Failure Diagram

Abstract A mathematical analysis of failure developments for tubular hydroforming under combined internal pressure and end feeding is presented in this paper. Under considerations are two distinct failure modes, namely the bursting and the wrinkling. Bursting is an instability phenomenon where the tube can’t sustain any more tensile loading. Splitting usually follows due to extreme deformations in the bursting area. Wrinkling is due to high compression load, which deteriates the qulity of the final product. The deformation theory of plasticity is utilized in this study that takes into account of material anisotropy. The governing equations for the onset of both failure modes are established. The results are presented as Hydroforming Failure Diagram in the End Feed – Internal Pressure space. A parametric study of the failure criteria for a variety of materials and process parameters is performed. It is shown that the material anisotropy plays a significant role. The results provide guidelines for product designers and process engineers for the avoidance of failure during hydroforming. The validity and applicability of current study are also discussed.

Applicability of Design Rules for Openings in Shells, ASME B&PV Code, Section VIII, Division 2 - A Case Study

2021 ◽  
Author(s):  
Gurumurthy Kagita ◽  
Krishnakant V. Pudipeddi ◽  
Subramanyam V. R. Sripada
Keyword(s):  
Stress Analysis ◽  
Failure Modes ◽  
Element Analysis ◽  
Design Rules ◽  
Area Method ◽  
Replacement Method ◽  
Local Stresses ◽  
Pressure Area ◽  
Section Viii ◽  
Division 2

Abstract The Pressure-Area method is recently introduced in the ASME Boiler and Pressure Vessel (B&PV) Code, Section VIII, Division 2 to reduce the excessive conservatism of the traditional area-replacement method. The Pressure-Area method is based on ensuring that the resistive internal force provided by the material is greater than or equal to the reactive load from the applied internal pressure. A comparative study is undertaken to study the applicability of design rules for certain nozzles in shells using finite element analysis (FEA). From the results of linear elastic FEA, it is found that in some cases the local stresses at the nozzle to shell junctions exceed the allowable stress limits even though the code requirements of Pressure-Area method are met. It is also found that there is reduction in local stresses when the requirement of nozzle to shell thickness ratio is maintained as per EN 13445 Part 3. The study also suggests that the reinforcement of nozzles satisfy the requirements of elastic-plastic stress analysis procedures even though it fails to satisfy the requirements of elastic stress analysis procedures. However, the reinforcement should be chosen judiciously to reduce the local stresses at the nozzle to shell junction and to satisfy other governing failure modes such as fatigue.

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