Estimation of Bending Collapse Load for Triangle Tubes

2020 ◽  
pp. 79-86
Author(s):  
Kenichi Masuda
Keyword(s):  
Collapse Load

Experimental Study of Ductile Fracture for Non-Aligned Multiple Flaws in a Plate

2009 ◽  
Author(s):  
Katsumasa Miyazaki ◽  
Kunio Hasegawa ◽  
Koichi Saito ◽  
Bostjan Bezensek
Keyword(s):  
Experimental Study ◽  
Ductile Fracture ◽  
Estimation Procedure ◽  
Maximum Load ◽  
Experimental Results ◽  
Collapse Load ◽  
Plate Specimen ◽  
Fracture Tests ◽  
Almost All

The fitness-for-service code requires the characterization of non-aligned multiple flaws for the flaw evaluation, which is performed using a flaw proximity rule. Worldwide almost all codes provide own proximity rule, often with unclear technical bases of the application of proximity rule to ductile fracture. To clarify the appropriate proximity rule for non-aligned multiple flaws in fully plastic fracture, fracture tests on flat plate specimen with non-aligned multiple through wall flaws were conducted at ambient temperature. The emphasis of this study was put on the flaw alignment rule, which determines whether non-aligned flaws are treated as independent or aligned onto the same plane for the purpose of flaw evaluations. The effects of the flaw separation and flaw size on the maximum load were investigated. The experimental results were compared with the estimations of the collapse load using the alignment rules in the ASME Section XI, BS7910 and API 579-1 codes. A new estimation procedure specific to the fully plastic fracture was proposed and compared with the comparison with the experimental results.

Effect of structural deformations and bend angle on the collapse load of pipe bends subjected to in-plane closing bending moment

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Silambarasan R. ◽  
Veerappan A.R. ◽  
Shanmugam S.
Keyword(s):  
Plastic Material ◽  
Large Strain ◽  
Bending Moment ◽  
Bend Angle ◽  
Plastic Collapse ◽  
Collapse Load ◽  
Pipe Bend ◽  
Content Type ◽  
Structural Deformations ◽  
Bend Angles

Purpose The purpose of this study is to investigate the effect of structural deformations and bend angle on plastic collapse load of pipe bends under an in-plane closing bending moment (IPCM). A large strain formulation of three-dimensional non-linear finite element analysis was performed using an elastic perfectly plastic material. A unified mathematical solution was proposed to estimate the collapse load of pipe bends subjected to IPCM for the considered range of bend characteristics. Design/methodology/approach ABAQUS was used to create one half of the pipe bend model due to its symmetry on the longitudinal axis. Structural deformations, i.e. ovality (Co) and thinning (Ct) varied from 0% to 20% in 5% steps while the bend angle (ø) varied from 30° to 180° in steps of 30°. Findings The plastic collapse load decreases as the bend angle increase for all pipe bend models. A remarkable effect on the collapse load was observed for bend angles between 30° and 120° beyond which a decline was noticed. Ovality had a significant effect on the collapse load with this effect decreasing as the bend angle increased. The combined effect of thinning and bend angle was minimal for the considered models and the maximum per cent variation in collapse load was 5.76% for small bend angles and bend radius pipe bends and less than 2% for other cases. Originality/value The effect of structural deformations and bend angle on collapse load of pipe bends exposed to IPCM has been not studied in the existing literature.

BENDING BEHAVIOR OF SIMPLY SUPPOTED METALLIC SANDWICH PLATES WITH DIMPLED CORES

2008 ◽  
Vol 22 (31n32) ◽  
pp. 6179-6184 ◽  
Author(s):  
DAE-YONG SEONG ◽  
CHANG GYUN JUNG ◽  
DONG-YOL YANG ◽  
DONG GYU AHN
Keyword(s):  
High Precision ◽  
Sandwich Plate ◽  
Sheet Thickness ◽  
Radius Of Curvature ◽  
Sandwich Plates ◽  
Collapse Load ◽  
Forming Process ◽  
Simply Supported ◽  
Bending Behavior ◽  
Sandwich Core

Metallic sandwich plates are lightweight structural materials with load-bearing and multi-functional characteristics. Previous analytic studies have shown that the bendability of these plates increases as the thickness decreases. Due to difficulty in the manufacture of thin sandwich plates, dimpled cores (structures called egg-box cores) are employed as a sandwich core. High-precision dimpled cores are easily fabricated in a sectional forming process. The cores are then bonded with skin sheets by multi-point resistance welding. The bending characteristics of simply supported plates were observed by the defining measure, including the radius ratio of the small dimple, the thickness of a sandwich plate, and the pattern angle (0°/90°, 45°). Experimental results revealed that sandwich plates with a thickness of 2.2 mm and a pattern angle of 0°/90° showed good bendability as the punch stroke under a collapse load was longer than other cases. In addition, the gap between attachment points was found to be an important parameter for the improvement of the bendability. Finally, sandwich plates with dimpled cores were bent with a radius of curvature of 330 mm for the sheet thickness of 2.2 mm using an incremental bending apparatus.

Effect of Bend Angle on Gross Plastic Deformation of Pipe Bends: A Finite Element Based Study

2015 ◽  
Author(s):  
Anindya Bhattacharya ◽  
Sachin Bapat ◽  
Hardik Patel ◽  
Shailan Patel
Keyword(s):  
Plastic Deformation ◽  
Finite Element ◽  
Failure Mechanisms ◽  
Bending Moment ◽  
Bend Angle ◽  
Piping System ◽  
Plastic Collapse ◽  
Collapse Load ◽  
Pipe Bend ◽  
Bend Angles

Bends are an integral part of a piping system. Because of the ability to ovalize and warp they offer more flexibility when compared to straight pipes. Piping Code ASME B31.3 [1] provides flexibility factors and stress intensification factors for the pipe bends. Like any other piping component, one of the failure mechanisms of a pipe bend is gross plastic deformation. In this paper, plastic collapse load of pipe bends have been analyzed for various bend parameters (bend parameter = tRbrm2) under internal pressure and in-plane bending moment for various bend angles using both small and large deformation theories. FE code ABAQUS version 6.9EF-1 has been used for the analyses.

scholarly journals Influence of multiple load indentation on the mechanical and material behaviour of steel cone-cylinder under axial compression

2021 ◽  
Author(s):  
Olawale Ifayefunmi ◽  
Sivakumar D. ◽  
Amir Hafiz Sazali
Keyword(s):  
Test Data ◽  
Good Accuracy ◽  
Cone Angle ◽  
Geometric Parameters ◽  
Collapse Load ◽  
Material Behaviour ◽  
Numerical Studies ◽  
Multiple Load ◽  
Welding Technique ◽  
Load Indentation

Abstract The first set of test data on axial collapse of cone-cylinder assembly having multiple load indentation (MLI) and its accompanying numerical studies is presented in this paper. Two perfect and two imperfect steel cone-cylinders were prepared in pairs. The cone-cylinder models have the following geometric parameters: cone radius of 40 mm, cylinder radius of 70 mm,wall thickness of 0.5 mm and cone angle of 16.7°. Cone and cylinder part were combined using Metal Inert Gas (MIG) welding technique. Results show that the repeatability of the experiment was good (3% for the perfect and 7% for the imperfect). Also, numerical prediction tends to reproduce the test data with good accuracy. The error between both approches ranges from 1% to -8%. Furthermore, the influence of geometric parameters are also significant in determining the collapse load of this type of structure. Finally, the worst multiple load indentation (WMLI) was explored for steel cone-cylinders assembly using different number of load indentations. Results indicate that as the number of indents increases, the sensitivity of the cone-cylinder models to imperfection also increases. However, at different imperfection amplitude, A, two regions were observed; (i) the region where cone-cylinder with N = 8 is more sensitive (A < 1.5), and (ii) the region where N = 4 produce the worst imperfection (1.5 < A ≤ 1.68).

scholarly journals OPTIMUM BUCKLING DESIGN OF CYLINDRICAL STIFFENER SHELL UNDER EXTERNAL HYDROSTATIC PRESSURE

2018 ◽  
Vol 18 (2) ◽  
pp. 239-252 ◽  
Author(s):  
Rawa Hamed M. Al-Kalali
Keyword(s):  
Hydrostatic Pressure ◽  
Numerical Optimization ◽  
Collapse Load ◽  
Ansys Software ◽  
External Hydrostatic Pressure ◽  
Buckling Mode ◽  
Design Elements ◽  
Design Variables ◽  
Thick Cylinder ◽  
Strength Constraints

This paper present an investigation of the collapse load in cylinder shell under uniformexternal hydrostatic pressure with optimum design using finite element method viaANSYS software. Twenty cases are studied inclusive stiffeners in longitudinal and ringstiffeners. Buckling mode shape is evaluated. This paper studied the optimum designgenerated by ANSYS for thick cylinder with external hydrostatic pressure. The primarygoal of this paper was to identify the improvement in the design of cylindrical shell underhydrostatic pressure with and without Stiffeners (longitudinal and ring) with incorporativetechnique of an optimization into ANSYS software. The design elements in this researchwas: critical load, design variable (thickness of shell (TH), stiffener’s width (B) andstiffener’s height (HF). The results obtained illustrated that the objective is minimizedusing technique of numerical optimization in ANSYS with optimum shell thickness andstiffener’s sizes. In all cases the design variables (thickness of shell) was thicker than themonocoque due to a shell’s thicker is essential to achieve the strength constraints. It can beconcluded that cases (17,18,19, and 20) have more than 90% of un-stiffened critical load.The ring stiffeners causes increasing buckling load than un-stiffened and longitudinalstiffened cylinder.

A note on calculating the collapse load for knee frames

1963 ◽  
Vol 11 (3) ◽  
pp. 318-320 ◽  
Author(s):  
W. Johnson
Keyword(s):  
Collapse Load
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