Local stress evaluation of rapid crack propagation in finite element analyses

The finite element analyses are carried out for the several piping components (D/T ≧ 100) subjected to in-plane or out-of-plane moment. For the stress evaluation of the chemical plant piping systems, ANSI B31.3 is usually applied. But the stress intensification factors and flexibility factors in this code are mainly for a heavy-wall-thickness pipe, so it is necessary to reconsider these factors for a thin-wall-thickness pipe with a large diameter. In our study, several finite element analyses using MSC/NASTRAN program were performed on the pipe bends (elbow or miter bend, 0.01 ≦ h ≦ 0.2) and the unreinforced fabricated tees (50 ≦ D/Tr ≦ 300, 0.5 ≦ d/D ≦ 0.95, 0.25 ≦ Tb/Tr ≦ 0.95), and the empirical formulas for the flexibility factors and the stress indices, due to out-of-plane or in-plane moment, were proposed. Experimental stress analyses for the piping components with D/Tr = 127 were also carried out, and it was confirmed that the results agreed well with the numerical ones.

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Piping Local Stresses for Solid Versus Hollow Attachments

Volume 3: Design and Analysis ◽

10.1115/pvp2005-71037 ◽

2005 ◽

Author(s):

C. Basavaraju ◽

R. C. Fox

Keyword(s):

Finite Element ◽

Wall Thickness ◽

Cylindrical Shells ◽

Local Stress ◽

Support Design ◽

Element Analysis ◽

Stress Evaluation ◽

Local Stresses ◽

Asme Code ◽

The Impact

The simple and most commonly used WRC-107 (Welding Research Bulletin #107) Bijlaard methodology for local stress evaluation addresses cylindrical shells and pipes with solid circular, rectangular, and square attachments only. Hollow circular, square, or rectangular tubular shaped attachments on cylindrical shells, though commonly used, are not addressed in WRC-107. ASME Code Case N-392 addresses hollow circular attachments on pipes but is known to be conservative. This paper studies commonly encountered sizes of hollow circular, hollow square, and hollow rectangular attachments of various wall thicknesses on piping utilizing rigorous finite element analysis (FEA) method to obtain the local stresses at the pipe/attachment interface due to mechanical loads. A total of fifty (50) finite element models were analyzed to study the most frequently used configurations. The impact of attachment wall thickness including solid attachment will be addressed. A comparison of finite element results with WRC-107 solid attachment results, when applicable, will be made. Recommendations and guidelines are provided based on the results of the FEA study. The objective is to reduce conservatism, and hence the associated cost in piping and pipe support design by optimizing the round attachment’s wall thickness.

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Lattice topology homogenization and crack propagation through finite element analyses

Procedia Structural Integrity ◽

10.1016/j.prostr.2020.10.074 ◽

2020 ◽

Vol 28 ◽

pp. 637-647

Author(s):

Florian Vlădulescu ◽

Dan Mihai Constantinescu

Keyword(s):

Finite Element ◽

Crack Propagation ◽

Finite Element Analyses

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Moving finite element analyses for fast crack propagation in sheet metal

International Journal of Mechanical Sciences ◽

10.1016/j.ijmecsci.2009.09.031 ◽

2010 ◽

Vol 52 (2) ◽

pp. 277-286 ◽

Cited By ~ 2

Author(s):

T. Fujimoto ◽

T. Nishioka

Keyword(s):

Finite Element ◽

Crack Propagation ◽

Sheet Metal ◽

Finite Element Analyses ◽

Moving Finite Element

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Mechanics Modeling of the Contact Loads on Dovetail Attachments

Journal of Applied Mechanics ◽

10.1115/1.4002566 ◽

2010 ◽

Vol 78 (2) ◽

Author(s):

Matthew C. Gean ◽

Thomas N. Farris

Keyword(s):

Finite Element ◽

Fatigue Life ◽

Life Prediction ◽

Engine Performance ◽

Local Stress ◽

Fatigue Life Prediction ◽

Performance Parameters ◽

Finite Element Analyses ◽

Contact Loads ◽

Empirical Constants

A procedure for calculating contact loads on a dovetail surface for given engine performance parameters such as speed and temperature is described. The procedure requires a small number of predetermined calibrating finite element analyses to obtain empirical constants. Verification is provided by detailed finite element analyses. Contact loads can be calculated for an entire mission history in near real-time. The contact load histories could be used to calculate local stress necessary for fatigue life prediction.

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