WRC Bulletin 516 1

[LSThill]

This bulletin reports on development of a three dimensional finite element model (3D FEM) to evaluate the effect of bending loads on the mechanical and tightness integrity of bolted flanged connections, and to compare the numerical results obtained with the 3D FEM to existing experimental data. Bolted flanged joints can be subjected to external loads from many different sources including thermal expansion of piping and piping components, misalignments of pipe supports, and non-symmetrical thermal expansion of the joint components. In most of theses cases bending moments are induced in the pipes and are transmitted to the flanges. For the design of bolted flanged joints, the effect of these moments must be accounted for as it can affect their mechanical and tightness behaviors. The use of the finite element technique for the analysis of bolted flanges subjected to non-symmetrical loadings is powerful and economical. This is particularly true for large dimension flanges for which experimental testing is very expensive and difficult to achieve. For non-symmetrical loading, the use of a three dimensional modeling of the joint components is appropriate to study the effect of external bending moments. A three dimensional model allows realistic behavior of the structure when compared to two dimensional model, particularly if the flange holes and the bolts need to be modeled. A three dimensional approach is essential to obtain a realistic circumferential and radial distribution of the gasket contact stress which is the key parameter that controls leakage.

The gasket stress distribution generated by flange rotation has a major impact on the leakage behavior of a bolted flanged joint. A special transducer, located in the flange beneath the gasket, to measure the radial variation of the contact stress developed in a bolted flanged connection has been developed and evaluated. The experimental results obtained with this transducer will be compared to the available numerical contact stress distributions obtained with a 3D-finite element model.

ISSN: 0043-2326
ISBN: 1-58145- 523-2
Library of Congress Catalog Card Number: 85-647116
Number of Pages: 85
and Development of a Transducer for Measuring Gasket Contact Stress

 

[TGS4]

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