An Experimental Study on the Evaluation of Failure Behavior of Pipe With Local Wall Thinning

2002 ◽  
Author(s):  
Jin Weon Kim ◽  
Chi Yong Park
Keyword(s):  
Internal Pressure ◽  
Failure Mode ◽  
Carrying Capacity ◽  
Axial Length ◽  
Failure Behavior ◽  
Load Carrying Capacity ◽  
Wall Thinning ◽  
Load Carrying ◽  
Deformation Ability ◽  
Local Wall Thinning

The pipe failure tests were performed using 102mm-Sch.80 carbon steel pipe with various simulated local wall thinning defects, in the present study, to investigate the failure behavior of pipe thinned by flow accelerated corrosion (FAC). The failure mode, load carrying capacity, and deformation ability were analyzed from the results of experiments conducted under loading conditions of 4-point bending and internal pressure. A failure mode of pipe with a defect depended on the magnitude of internal pressure and axial thinning length as well as stress type and thinning depth and circumferential angle. Also, the results indicated that the load carrying capacity and deformation ability were depended on stress state in the thinning region and dimensions of thinning defect. With increase in axial length of thinning area, for applying tensile stress to the thinning region, the dependence of load carrying capacity was determined by circumferential thinning angle, and the deformation ability was proportionally increased regardless of the circumferential angle. For applying compressive stress to thinning region, however, the load carrying capacity was decreased with increase in axial length of the thinned area. Also, the effect of internal pressure on failure behavior was characterized by failure mode of thinned pipe, and it promoted crack occurrence and mitigated a local buckling of the thinned area.

scholarly journals Experimental Investigation on the Failure Behavior of Carbon Fiber Reinforced Polymer (CFRP) Strengthened Reinforced Concrete T-beams

2021 ◽  
Vol 23 (2) ◽  
pp. 115-122
Author(s):  
Junaedi Utomo ◽  
Muhammad Nur Khusyeni ◽  
Windu Partono ◽  
Ay Lie Han ◽  
Buntara S. Gan
Keyword(s):  
Carbon Fiber ◽  
Failure Mode ◽  
Carrying Capacity ◽  
Fiber Reinforced Polymers ◽  
Failure Behavior ◽  
Load Carrying Capacity ◽  
Fiber Reinforced ◽  
Conventional Concrete ◽  
Load Carrying ◽  
Carbon Fiber Reinforced

Carbon Fiber Reinforced Polymers (CFRP) are widely used as external concrete reinforcement. The behavior of T-beams strengthened in shear and flexure using CFRP sheets and plates was studied to analyze the load carrying capacity and failure mode as compared to conventional concrete members. The bonding response of the plate-to-concrete was investigated by comparing a specimen with a plate anchored at the far ends, one without anchoring. The sheets were in situ wet lay-up, the plate was pre-impregnated and pultruded during manufacturing. The test result suggested that this integrated strengthening method notably improved the load-carrying capacity, it was also demonstrated that anchoring had a positive but insignificant effect on the moment capacity and deformation. The influence of anchoring was noteworthy from the point of view that it shifted the failure mode from debonding to CFRP plate rupture. The most important factors influencing the behavior of CFRP strengthened beams are outlined.

Investigation of Burst Pressure in T-Joints With Wall-Thinning by Using FEA

2017 ◽  
Author(s):  
Atsushi Yamaguchi
Keyword(s):  
Carrying Capacity ◽  
Safety Margin ◽  
Pressure Vessels ◽  
Burst Pressure ◽  
Load Carrying Capacity ◽  
Working Pressure ◽  
Element Analysis ◽  
T Joints ◽  
Wall Thinning ◽  
Load Carrying

Boilers and pressure vessels are heavily used in numerous industrial plants, and damaged equipment in the plants is often detected by visual inspection or non-destructive inspection techniques. The most common type of damage is wall thinning due to corrosion under insulation (CUI) or flow-accelerated corrosion (FAC), or both. Any damaged equipment must be repaired or replaced as necessary as soon as possible after damage has been detected. Moreover, optimization of the time required to replace damaged equipment by evaluating the load carrying capacity of boilers and pressure vessels with wall thinning is expected by engineers in the chemical industrial field. In the present study, finite element analysis (FEA) is used to evaluate the load carrying capacity in T-joints with wall thinning. Burst pressure is a measure of the load carrying capacity in T-joints with wall thinning. The T-joints subjected to burst testing are carbon steel tubes for pressure service STPG370 (JIS G3454). The burst pressure is investigated by comparing the results of burst testing with the results of FEA. Moreover, the maximum allowable working pressure (MAWP) of T-joints with wall thinning is calculated, and the safety margin for the burst pressure is investigated. The burst pressure in T-joints with wall thinning can be estimated the safety side using FEA regardless of whether the model is a shell model or a solid model. The MAWP is 2.6 MPa and has a safety margin 7.5 for burst pressure. Moreover, the MAWP is assessed the as a safety side, although the evaluation is too conservative for the burst pressure.

Progressive Failure Analysis of an Integral Composite Joint for Thrust Reverser Cascade

2019 ◽  
Vol 795 ◽  
pp. 325-332
Author(s):  
Ji Shen Yang ◽  
Hong Yu Qi ◽  
Xiao Guang Yang ◽  
Duo Qi Shi
Keyword(s):  
Carrying Capacity ◽  
Composite Structure ◽  
Progressive Failure ◽  
Damage Model ◽  
Research Work ◽  
Failure Behavior ◽  
Load Carrying Capacity ◽  
Composite Joint ◽  
Bending Load ◽  
Load Carrying

The research work in this paper is focused on studying the failure behavior of an integral π-shaped laminated composite structure subjected to a bending load. A progressive damage model based on the 3D Tsai-Wu failure criterion and a developed gradual degradation model was employed to simulate and assess the load-carrying capacity, the onset and propagation of damage, and the failure mechanisms. For this unique π-shaped composite structure, disbonding was found to be the dominant damage mode under bending load, and the approximate maximum load could be maintained for a brief time during the final failure due to the gradual loss nature of the load-carrying capacity. The extent of damage was found to be more serious on the side of Rib II compared to the other side.

Limit Load Analysis of Cylindrical Vessels Under Internal Pressure and Axial Strain

2011 ◽  
Author(s):  
Xian-Kui Zhu
Keyword(s):  
Internal Pressure ◽  
Carrying Capacity ◽  
Pressure Vessel ◽  
Axial Strain ◽  
Limit State ◽  
Limit Load ◽  
Operating Pressure ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Load Analysis

Strain-based design is a newer technology used in safety design and integrity management of oil and gas pipelines. In a traditional stress-based design, the axial stress is relatively small compared to the hoop stress generated by internal pressure in a line pipe, and the limit state in the pipeline is usually load-controlled. In a strain-based design, however, axial strain can be large and the load-carrying capacity of pipelines could be reduced significantly below an allowed operating pressure, where the limit state is controlled by an axial strain. In this case, the limit load analysis is of great importance. The present paper confirms that the stress, strain and load-carrying capacity of a thin-walled cylindrical pressure vessel with an axial force are equivalent those of a long pressurized pipeline with an axial tensile strain. Elastic stresses and strains in a pressure vessel are then investigated, and the limit stress, limit strain and limit pressure are obtained in terms of the classical Tresca criterion, von Mises criteria, and a newly proposed average shear stress yield criterion. The results of limit load solutions are analyzed and validated using typical experimental data at plastic yield.

Interconnection of widely spaced angles

1988 ◽  
Vol 15 (4) ◽  
pp. 732-741 ◽  
Author(s):  
Murray C. Temple ◽  
Joo Chai Tan
Keyword(s):  
Key Words ◽  
Failure Mode ◽  
Carrying Capacity ◽  
Structural Design ◽  
Failure Load ◽  
Building Codes ◽  
Load Carrying Capacity ◽  
Insignificant Effect ◽  
Load Carrying ◽  
Theoretical Results

Research on the interconnection of widely spaced back-to-back angles has not been conducted. This research was carried out with the aim of developing rules for the design and spacing of interconnectors in such members. Four parameters—the number of interconnectors, the back-to-back spacing between angles, the weld pattern used to connect the interconnectors to the angles, and the thickness of the interconnectors—were studied. The experimental and the theoretical results for the slender double angles confirm that only one interconnector, of practical proportions, is required to make the widely spaced angles act as an integral unit. Both the separation between angles, within reason, and the weld pattern used to connect the interconnectors to the angles had an insignificant effect on the failure load and the failure mode. The thickness of the interconnector did affect the load-carrying capacity of the strut, but only when the thickness of the interconnector was impractically small. The forces and moments in the interconnectors are very small. Key words: angles, back-to-back, buckling, building (codes), columns (structural), design interconnection.

Investigation of Burst Pressure in Pipes With Square Wall Thinning by Using FEA and API579 FFS-1

2013 ◽  
Author(s):  
Atsushi Yamaguchi
Keyword(s):  
Carrying Capacity ◽  
Safety Margin ◽  
Pressure Vessels ◽  
Fe Analysis ◽  
Burst Pressure ◽  
Load Carrying Capacity ◽  
Working Pressure ◽  
Accelerated Corrosion ◽  
Wall Thinning ◽  
Load Carrying

Boilers and pressure vessels are heavily used in chemical industrial plants and equipment is inspected periodically for damage. The most common type of damage is wall thinning due to Flow-Accelerated Corrosion (FAC) or corrosion under insulation (CUI). Any damage must be repaired or replaced as necessary. On the other hand, optimization of the time required in order to replace damaged equipment by evaluating the load carrying capacity of pipes with wall thinning is expected in chemical industrial field. In the present study, FE analysis is used in order to evaluate the load carrying capacity in pipes with wall thinning. Burst pressure is a measure of the load carrying capacity in pipes with wall thinning. The pipes subjected to burst testing are carbon steel tubes for pressure service STPG370 (JIS G3454). The examined wall thinning is rectangular, and the eroded depth is half the pipe wall thickness. The burst pressure is investigated by comparing the results of burst testing with the results of FE analysis. Moreover, the reduced maximum allowable working pressure (MAWPr), which is calculated by fitness-for-service (FFS) assessment, and the safety margin for burst pressure are investigated. The burst pressure calculated by FEA agrees well with the test results, except for square wall thinning for circumferential angles of less than 15°. Also, the safety margin of MAWPr based on FFS-1 Part 4 is over 4.0 times for burst pressure.

scholarly journals Load-carrying capacity and failure mode of composite steel-concrete truss element under monotonic loading

2020 ◽  
Vol 982 ◽  
pp. 012032
Author(s):  
Nanang Gunawan Wariyatno ◽  
Yanuar Haryanto ◽  
Ay Lie Han ◽  
Buntara Sthenly Gan ◽  
Gathot Heri Sudibyo
Keyword(s):  
Failure Mode ◽  
Carrying Capacity ◽  
Monotonic Loading ◽  
Load Carrying Capacity ◽  
Truss Element ◽  
Load Carrying ◽  
Composite Steel

FAILURE BEHAVIOR OF ELBOWS WITH LOCAL WALL THINNING

2008 ◽  
Vol 22 (11) ◽  
pp. 845-850 ◽  
Author(s):  
SUNG-HO LEE ◽  
JEONG-KEUN LEE ◽  
JAI-HAK PARK
Keyword(s):  
Test System ◽  
Failure Behavior ◽  
Piping System ◽  
Bending Tests ◽  
Steel Pipes ◽  
Wall Thinning ◽  
Load Carrying ◽  
Set Up ◽  
Aging Phenomena ◽  
Local Wall Thinning

Wall thinning defect due to corrosion is one of major aging phenomena in carbon steel pipes in most plant industries, and it results in reducing load carrying capacity of the piping components. A failure test system was set up for real scale elbows containing various simulated wall thinning defects, and monotonic in-plane bending tests were performed under internal pressure to find out the failure behavior of them. The failure behavior of wall-thinned elbows was characterized by the circumferential angle of thinned region and the loading conditions to the piping system.

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