Shakedown (continuum mechanics)

In continuum mechanics, elastic shakedown behavior is one in which plastic deformation takes place during running in, while due to residual stresses or strain hardening the steady state is perfectly elastic.

Plastic shakedown behavior is one in which the steady state is a closed elastic-plastic loop, with no net accumulation of plastic deformation.

Ratcheting behavior is one in which the steady state is an open elastic-plastic loop, with the material accumulating a net strain during each cycle.

Ratcheting Check

Not needed for only primary loading that meets static loading requirements.

Needed for cyclic thermal loading plus primary loading with a mean.

References

1. Shakedown of Elastic-Plastic Structures, Jan A. Konig, Elsevier, 1987.

2. Limit Analysis of Structures at Thermal Cycling, D. A. Gokhfeld and O. F. Cherniavsky, 1980.

3. ASME Boiler and Pressure Vessel Code, American Society of Mechanical Engineers, New York, 2001.

4. "Elastic-Plastic Behaviour of Thin-Tubes Subjected to Internal Pressure and Intermittent High-Heat Fluxes with Application to Fast-Nuclear Reactor Fuel Elements," J. Bree, J. Strain Analysis, Vol.2(3), pp 226-228, 1967.