Determination of bend angle and shape imperfection effect on collapse load of pipe bends under in-plane opening moment

Silambarasan, R.; Veerappan, Ar.; Shanmugam, S.

doi:10.1177/09544089221113640

Cited by 2 publications

(3 citation statements)

References 55 publications

(75 reference statements)

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“…The straight pipes nullify the end effects produced by the boundary constraints and permit propagation of the effects of shape imperfections. [22][23][24][25][26] For a detailed analysis, a range of pipe bends was selected to include short to long-bend radii and thin walls to thick walls considering various combinations of the TWCC angle and shape distortions. Table 1 presents the dimensions chosen for the pipe bend 27 per the mandates of the ASME B&PV code, section II.…”

Section: Geometrical Parameters and Materials Propertiesmentioning

confidence: 99%

“…This study constituted some assumptions regarding the pipe bend's geometry to incorporate structural distortions. 13,22–24 Figure 2 shows the elliptic cross-sectioned pipe bend with TWCC postulated at the 45°. The degree of ovality false( C o false) and thinning false( C t false) was defined and derived in percentage, as shown in equations (7) and (8).…”

Section: Shape Distortion In Pipe Bendsmentioning

confidence: 99%

“…Ovality false( C o false) and thinning false( C t false) 0.25em were increased from 0% to 20% with an increment of 5% at every step. 22–24 The circumferential crack ( 2 θ) at the intrados was taken as 0°, 45°, 60°, and 90° for which the corresponding relative crack lengths ( θ/π) were 0, 0.125, 0.167, and 0.25, respectively. 28,29 The material considered was Type 304 SS, generally used in the piping system, with a 0.26 Poisson's ratio 0.25em false( γ false), yield stress ( σ o false) of 271.93 MPa, and Young's modulus ( E ) of 193 GPa.…”

Section: Fe Analysismentioning

confidence: 99%

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Development of an improved structural integrity assessment correlation for circumferential through-wall cracked 90° shape-distorted pipe bends subjected to in-plane opening bending moment

Thulasiraj,

Arunachalam

2023

Proceedings of the Institution of Mechanical Engineers, Part L:

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A detailed and systematic assessment of the plastic collapse load of 90° shape imperfect pipe bends subjected to in-plane opening bending was conducted by implementing three-dimensional non-linear finite element analyses. The material considered in the analysis is the elastic-perfectly plastic type with a large change geometry option. Shape distortions in the pipe's cross-section and through-wall circumferential crack at the intrados region were the defects analyzed in this study. Ovality [Formula: see text] and thinning [Formula: see text] were varied from 0% to 20% with a 5% incrementation, and crack angles of 45°, 60°, and 90° were considered at the intrados. The twice-elastic slope method effectively evaluates the plastic collapse moment as mandated by the ASME B&PV code NB-3213.25, section III. The reaction moment and angular rotation curves were generated for all pipe bend models. The outcomes of the analysis revealed that the plastic collapse moment load of pipe bends was affected by through-wall circumferential crack and [Formula: see text], while thinning produced negligible effect, which was subsequently excluded from the analysis. The combined effect of through-wall circumferential crack and [Formula: see text] produces a consequential influence on the pipe bend at 45° angle, which is severe at 60°, and even more critical at 90°. In the analysis, the plastic collapse moment for short bend radius was reduced, while that of thin-walled pipe bends increased with an increase in thickness and bend radius. The plastic collapse moment of the present analysis was validated using experimental data acquired from open literature. An enhanced structural correlation assessment was proposed for through-wall circumferential crack shape-distorted 90° pipe bends.

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Section: Geometrical Parameters and Materials Propertiesmentioning

confidence: 99%

Section: Shape Distortion In Pipe Bendsmentioning

confidence: 99%

Section: Fe Analysismentioning

confidence: 99%

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Development of an improved structural integrity assessment correlation for circumferential through-wall cracked 90° shape-distorted pipe bends subjected to in-plane opening bending moment

Thulasiraj,

Arunachalam

2023

Proceedings of the Institution of Mechanical Engineers, Part L:

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Development of new improved plastic collapse moment equations of pressurized different angled pipe bends under bending moments

Kumar,

Kumar

et al. 2024

Proceedings of the Institution of Mechanical Engineers, Part E:

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In a piping system, pipe bends are more flexible than straight pipes because of their curved geometry, supplemented by higher stress and strain concentration, leading to one of the crucial components in piping industries. Therefore, safe design of pipe bends is essential for smooth running of the piping system, and plastic collapse moment is one of its criteria. This paper utilizes three-dimensional finite element analyses to model empirical solutions for the plastic collapse moment for different angled pipe bends subjected to combined pressure and in-plane closing, in-plane opening, and out-of-plane bending moments. Plastic collapse moments for 30∘ to 180∘ pipe bends are determined for elastic perfectly plastic and strain hardening materials, employing large geometry change option and internal pressure effect. It is observed from results that pressure effect is more prominent in thinner pipe bends of larger bend angle under all bending cases. For in-plane opening and out-of-plane bending moments, collapse moment increases and then decreases with increase in pressure intensity for all sizes of pipe bend. However, for in-plane opening bending moment, collapse moments keep on decreasing for thicker ([Formula: see text] = 11.33) pipe bends. Finally, the study presents new improved plastic collapse moment solutions for different angled pipe bends under bending moment and internal pressure, derived from the finite element results of elastic perfectly plastic and strain hardening material models.

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Determination of bend angle and shape imperfection effect on collapse load of pipe bends under in-plane opening moment

Cited by 2 publications

References 55 publications

Development of an improved structural integrity assessment correlation for circumferential through-wall cracked 90° shape-distorted pipe bends subjected to in-plane opening bending moment

Development of an improved structural integrity assessment correlation for circumferential through-wall cracked 90° shape-distorted pipe bends subjected to in-plane opening bending moment

Development of new improved plastic collapse moment equations of pressurized different angled pipe bends under bending moments

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