A new four-dimensional ratcheting boundary: Derivation and numerical validation

Abstract

A new four-dimensional ratcheting boundary is derived analytically for the first time considering the interaction among four types of stresses: constant mechanical membrane stress, mechanical bending stress, cyclic thermal membrane stress, and thermal bending stress. A uniaxial beam model is used to derive the closed-form ratcheting boundary for these combined cyclic and constant loadings.The Tresca yield condition and elastic-perfectly plastic behavior are assumed. A novel two-plane FE model is proposed for numerical validation and the results predicted by analytical solution agree very well with that obtained by two-plane FE model. The solution of the classical Bree problem is the one of special cases when this new four-dimensional ratcheting boundary is reduced into two-dimensional style. The relationship between the threedimensional ratcheting boundary adopted by the newly implemented ASME VIII -2 Pressure Vessel Code and the proposed four-dimensional ratcheting boundary is also discussed.

Elastic core concept for modified Bree problems considering in-phase and out-of-phase loading conditions

“…(11)(12)(13)(14)(15)(16) and the effective creep stress parameters given by Eqs. (18)(19)(20)(21)(22), the above theoretical solutions and numerical solutions based on the finite element step-by-step analysis are compared. The common two-plane model proposed by the authors [22] for uniaxial Bree-type problems is adopted for numerical analysis, as shown in Fig.…”

“…The mismatch between the simplified assessment method and the actual situation will lead to conservative or non-conservative problems. Currently, some progress has been made in the modified Bree problems considering the effects of multiple stress parameters, such as the work of Reinhardt [18], Adibi-Asl [19], Shen [20], Bao [21,22], etc. The development of a multi-dimensional effective creep stress parameter diagram is worthy of further study.…”

Shakedown and ratcheting analysis of Printed Circuit Heat Exchangers under multiple cyclic mechanical and thermal loads

“…Ratcheting is an accumulated inelastic deformation or strain. Ratcheting may occur when a component subjected to cyclic mechanical stress, thermal stress, or their combination [3]. When cyclic thermal stress existed, thermal stress ratcheting may happen.…”

Evaluation of Sensitivity and Calibration of the Chaboche Kinematic Hardening Model Parameters for Numerical Ratcheting Simulation

“…where, α i can be calculated from the monotonic test and upper hysteresis curves by Equations (10) and (11), respectively.…”

“…Offshore structures, pressure vessels and piping system, structures operating in earthquake zones, airplane landing gears and nuclear reactors are typical examples of such components and structures [6][7][8]. Structures subjected to stress cycles beyond the elastic limit oblige a trustworthy design, especially in the presence of a significant mean stress from loads such as dead weight or internal pressure [1,6,9,10].…”