9. Conclusion

However sensitive they may be, Level 1 piping calculations are carried out in the elastic domain wherever possible. This facilitates modeling and analysis of results.

The regulatory criteria provided by the codes, on the other hand, are based on elastoplastic considerations and are designed to protect equipment against various types of damage:

• excessive deformations, associated with primary loads imposing forces (own weight, primary part of the earthquake). Secondary loads, which impose deformations, are in fact self-limiting by their very nature;

• progressive deformation. The notions of plastic adaptation and plastic accommodation are introduced to ensure that piping behavior is either elastic or can be assimilated to elastic behavior. If this is not the case, piping systems find themselves in the...