Design of Process Equipment Beam Joints to Utilise Stress Relaxation

Ilkka Pöllänen; Heikki Martikka

doi:10.4028/www.scientific.net/MSF.638-642.2664

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Sensitivity Analysis as a Tool of Optimal Sensors Location for Solidification Parameters Estimation
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Simulative Accelerated Creep Test on Gleeble
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Simulation of Evolution of Dual-Phase Microstructure
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Strength of Alloyed Metal Castings Using Multiphase Models and Non-Linear FEM
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Design of Process Equipment Beam Joints to Utilise Stress Relaxation
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Numerical Simulation of the Portevin – Le Chatelier Effect in Various Material and at Different Scales
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Numerical Modeling of Casting Solidification Using Generalized Finite Difference Method
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Numerical Thermo-Mechanical Modelling of Stress Fields and Residual Constraints in Metallic Targets Subject to Laser Shock Processing
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A Model for Nucleation and Growth Processes of Tin Whisker
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HomeMaterials Science ForumMaterials Science Forum Vols. 638-642Design of Process Equipment Beam Joints to Utilise...

Design of Process Equipment Beam Joints to Utilise Stress Relaxation

Abstract:

In design of process equipment and hot vessel beam joints the real effect of relaxation is considered. Standards make an allowance that some relaxation of stresses at joint could be advantageous in relieving the stress peaks due to reaction moments. Magnitude of the moments in itself is not the problem but the stress distribution caused by it. The goal in this study is to estimate the possibility of taking advantage of relaxation in design using as test case a rectangular beam. Analytical theory of creep is applied with constant bending moment load. Stress distribution is first linear elastic and then flattens to nonlinear form resembling the elastic plastic bending. FEM gave analogous results constant moment and time dependent strain. One advantage is that fatigue life is increased at these joints after moderate amount of creep relaxation.

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Periodical:

Materials Science Forum (Volumes 638-642)

Pages:

2664-2669

DOI:

https://doi.org/10.4028/www.scientific.net/MSF.638-642.2664

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Online since:

January 2010

Authors:

Ilkka Pöllänen, Heikki Martikka

Keywords:

Creep, Fatigue, Finite Element Model (FEM), Relaxation, Simulation

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References

[1] J.T. Boyle J T , J. Spence : Stress analysis for creep, Butterworths (1983).

Google Scholar

[2] ASME (2006).

Google Scholar

[3] NX Nastran FEM program.

Google Scholar

[4] S. Kaliszky: Plastizitätslehre. Theorie und technische Anwendungen, VDI-Verlag, (1984).

Google Scholar

[5] W. J. Evans, G. F. Harrison: The development of a universal equation for secondary creep rates in pure metals and engineering alloys, Metal Science , Sept 1976, pp.307-313.

DOI: 10.1179/msc.1976.10.9.307

Google Scholar

[6] N.E. Dowling, Mechanical behavior of materials, Prentice Hall, (1998).

Google Scholar

[7] SIMNON, Simulation Language for Nonlinear Systems, Lund Institute of Technology, SSPA Systems, Version 3. 0 , January (1990).

Google Scholar