Parametric Nonlinear Finite Element Analysis of Strain Ratcheting in Pressurized Elbows Based on Random Vibration

Article type: Research Article

Authors: Zhao, Yong | Stevenson, John D. | Tang, H.T.

Affiliations: Engineering Mechanics Group, Battelle Memorial Institute, 505 King Avenue, Columbus, OH 43201 | Stevenson and Associates, 9217 Midwest Avenue, Cleveland, OH 44125 | Electric Power Research Institute, Department of Nuclear Safety, PO Box 10412, Palo Alto, CA 94303

Abstract: The large strain ratcheting in cyclic plasticity of a typical pressurized pipe elbow in a realistic nuclear piping system was investigated in a more quantitative manner than previously. The elbow was modeled using a fine mesh of shell elements that can provide the completed information of detailed time varying strain distributions in the whole elbow area. The nonlinear time history stress analyses performed were based on a pseudostatic concept using the vector-valued stochastic displacement response time series loaded at the elbow ends. The response time series were synthesized using a simulation approach based on the random vibration analyses of the piping system and its supporting building. After a finite element mesh convergence study, parametric analyses were conducted that included the effects due to the magnitude changes in excitation level, internal pressure, material yield stress, and material strain hardening.

DOI: 10.3233/SAV-1996-3506

Journal: Shock and Vibration, vol. 3, no. 5, pp. 373-387, 1996