Méthodes spectrales pour une analyse en fatigue des structures métalliques sous chargements aléatoires multiaxiaux

Doctorat en sciences appliquéesinfo:eu-repo/semantics/nonPublishe

Multiaxial Random Fatigue Life Prediction of Metallic Structures from Spectral Data

info:eu-repo/semantics/nonPublishe

Discussion: “estimating the probability distribution of von mises stress for structures undergoing random excitation”

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Spectral methods for multiaxial random fatigue analysis of metallic structures

This paper presents computationally efficient frequency domain methods for estimating the high-cycle fatigue life of metallic structures subjected to a random multiaxial loading. The equivalent von Mises stress method proposed earlier by the senior author is first reviewed. It is then shown that the multiaxial rainflow method, initially formulated in the time domain, can be implemented in the frequency domain in a formally similar way. The consistency of the results are checked by comparison with a time domain method based on the critical plane. It is observed that frequency domain methods produce enormous computer savings and correlate fairly well with the time domain method in terms of localizing the critical areas in the structure. A frequency domain implementation of Crossland's failure criterion is also proposed; it is found in very good agreement and much faster than its time domain counterpart.info:eu-repo/semantics/publishe

Spectral methods to estimate local multiaxial fatigue failure for structures undergoing random vibrations

FLWINinfo:eu-repo/semantics/publishe

Tools for a multiaxial fatigue analysis of structures submitted to random vibration

ESA SP-428, February 1999info:eu-repo/semantics/nonPublishe

Some Tools for Multiaxial Random Fatigue Analysis with Finite-Elements

info:eu-repo/semantics/publishe

Estimation du dommage en fatigue multiaxiale de structures métalliques soumises à des vibrations aléatoires

info:eu-repo/semantics/publishe

PVP2010-25736 SIMULATION AND MEASUREMENT OF THROUGH-WALL RESIDUAL STRESSES IN A STRUCTURAL WELD OVERLAID PRESSURIZER NOZZLE

ABSTRACT Full structural weld overlays (FSWOLs) have been used extensively as a repair/mitigation technique for primary water stress corrosion cracking (PWSCC) in pressurizer nozzle dissimilar metal (DM) welds. To support an approved FSWOL design and safety submission for British Energy pressurized water reactor (PWR) nozzles, an in-depth evaluation was performed to assess the effects of a FSWOL on the throughwall residual stress distribution in safety/relief pressurizer nozzles. Two safety/relief pressurizer nozzle mockups were fabricated based on British Energy's PWR nozzle design. One mockup included the nozzle to safe-end DM weld and the safe-end to stainless steel weld while the second mockup included the DM weld, the stainless steel weld and a Westinghouse-designed structural weld overlay. The mockups were fabricated utilizing materials and techniques that represented the plant-specific nozzles as closely as possible and detailed welding parameters were recorded during fabrication. All welds were subsequently nondestructively evaluated (NDE). A thorough review of the detailed fabrication records and the NDE results was performed and several circumferential positions were selected on each mockup for subsequent residual stress measurement. The through-wall residual stress profiles were experimentally measured through the DM weld centerline at the selected circumferential positions using both the deep hole drilling (DHD) and incremental deep hole drilling (iDHD) measurement techniques. In addition to experimental residual stress measurements, the through-wall residual stress profiles were simulated using a 2-D axisymmetric ANSYS™ finite element (FE) model. The model utilized kinematic strain hardening and the temperature constraint method which greatly simplified the simulation as compared to detailed heat source modeling methods. A range of residual weld stress profiles was calculated by varying the time at which the temperature constraints were applied to the model. The simulation results were compared to the measurement results. It was found that the effects of the FSWOL were principally three fold. Specifically, the FSWOL causes a much deeper compressive stress field, i.e., the overlay shifts tension out towards the outside diameter surface. Further, the FSWOL reduces tension in the underlying dissimilar metal weld, and finally, the FSWOL causes higher peak compressive and tensile residual stresses, both of which move deeper into the nozzle wall after the overlay is applied. Relatively good agreement was observed between the FE results and the measurements results. BACKGROUND The project involved multi-disciplinary team members from British Energy