... and justification for this proposed change. Historically, the Criteria Document from 1972 defined the ratcheting limit strictly in terms of yield, going so far as to state that “a calculated elastic stress range equal to twice the yield stress has a very special significance”. This document goes further to define...

... their operational lifespan from a sealability perspective. Unlike the classical ratcheting model of Bree, which is based on the combination of primary membrane stress and alternating secondary bending stress in the same direction, ratcheting in this context may occur solely due to secondary stresses during...

... be estimated by detailed finite element analyses. In the opinion of the authors, this effect deserves more attention. This is particularly true for simplified elastic-plastic methods for fatigue and ratcheting assessment of structures subjected to cyclic loading. Cyclic loading may cause elastic-plastic...

... Abstract The failure mode estimation of essential components in nuclear facilities under beyond design-basis events (BDBEs) is necessary to mitigate the consequences during severe accident conditions. The plastic collapse induced by ratcheting, defined as the ratchet-induced collapse...

... Abstract Ratcheting and shakedown anomalies are investigated for impulsively loaded vessels. Calculated results for explosive containment vessels subjected to repeated dynamic loading are used to illustrate behaviors that differ markedly from classical ratcheting/shakedown (i.e., the phenomenon...

... measurements are obtained, indicating significant strain ratcheting at the critical locations of the elbows. The piping system failed under low-cycle fatigue undergoing through-thickness cracking at the flank of the most strained elbow. Post-fatigue metallographic examination of the elbows indicated...

... of nonlinear ratcheting behavior under cyclic loading is studied. The method of determining the parameters of constitutive model based on cyclic stable stress-strain curve is also studied. A sensitive study of the parameters for the same constitutive law is presented, including the results of cumulative...

... Abstract Ratcheting assessment by elastic-plastic stress analysis is presented in ASME VIII-2, paragraph 5.5.7. There are three criteria. The first one is strict in engineering design. It’s hard for most of structures to satisfy it. If the plastic strain in the structure is zero, it means...

... the adhesion between pipe and patch, leading the repair to fail prematurely. pipe repair metallic patches fatigue ratcheting adaptation FATIGUE BEHAVIOR OF METALLIC PIPES WITH THROUGH-WALL CORROSION DAMAGE REPAIRED WITH BONDED METALLIC PATCHES Camila de Luca1, Julia Sathler1, João Fellipe Souza1...

... is loaded with a constant axial force and subjected to cyclic shear and cyclic internal pressure. In general, for structures exhibiting ratcheting, hundreds or more load cycles must be analysed via step-by-step calculations until the shakedown state is reached. Using the STPZ, post-shakedown quantities...

... Abstract In order to investigate the ratcheting behavior and to determine new design rules, some experimental tests were conducted in many countries in the last decades. In France, some tests were carried out under mechanical or thermal cyclic loading to examine this risk. The first section...

.... coke drums coking strain ratcheting bulging thermal gradient fatigue A METHOD TO ESTIMATE DEFORMATION STRAINS IN THE CONTEXT OF COKE DRUM LIFE ASSESSMENTS: PART 1 John Huang Stress Engineering Services, Inc. Houston, Texas, USA [email protected] Kannan Subramanian Stress Engineering...

... Abstract Thermal ratcheting is required to be checked by most of the piping design codes, specifically the ASME B&PV Code. For cases where the variation of temperature distribution is not uniform, the existing ratchet check methodology for piping is inadequate and therefore the finite...

.... Viscoplasticity has to be taken into account for cyclic loading modelling in the case of conventionally produced SS316L but not for the 3D printed material. A set of low-cycle fatigue tests was performed on specimens from both used production technologies. Uniaxial ratcheting tests were realized under constant...

... The classical approaches in shakedown analysis are based the assumption that the stresses are eventually within the elastic range of the material everywhere in a component (elastic shakedown). Therefore, these approaches are not very useful to predict the ratcheting limit (ratchet limit...

... The first objective of this paper investigates the influence of the previous strain history on ratcheting of the 304 L stainless steel on ambient temperature. The identification is done using the Chaboche constitutive model. New tests were performed where different strain-controlled histories...

... 24 07 2009 A simple and systematic procedure is proposed for shakedown analysis using combination of linear and non-linear finite element analysis (FEA). The method can identify the boundary between the shakedown and ratcheting domains directly does not require a time history analysis...

... Bree model core stress ratcheting plasticity shakedown yield strength The Bree model and the elastic core concept have been used as the foundation for the simplified inelastic design analysis methods in the ASME Code for the design of components at elevated temperature for nearly...