... and stress relaxation models for cyclic softening/hardening material are incorporated in the model. Materials data conducted by authors and collected from references are employed for validations. Results indicated that the improved models proposed could present more realistic evolution behavior of materials...

... 2009 29 10 2010 29 10 2010 creep fission reactor safety internal stresses nuclear reactor steam generators pipes stress relaxation Some steam generators are used to transfer the heat from primary sodium circuit to secondary water circuit. The need to evacuate the flows...

... with the viscoplasticity theory based on overstress. A systematic procedure for determining model parameters is presented and the model is employed to predict the response of the material under various test histories. 24 04 2008 15 07 2008 21 04 2009 deformation polymers stress relaxation stress...

... loading to its critical size causing fast fracture. In fatigue-creep interaction at the shaft surface, high tensile residual stress relaxation under high operating temperature causes creep crack initiation. The cracks may then grow under the combination of cyclic loading and high operating temperature...

... the observed non Masing behavior of the steel. Some important cyclic phenomena, observed for the studied steel, such as the cyclic creep and the cyclic stress relaxation, are illustrated. Strain, stress, and energy based relations for fatigue life prediction until crack initiation, are evaluated based...

...Brent H. Chance, Graduate Student; Don E. Bray, Associate Professor This study investigates transverse stress relaxation in welded steel plates. Two different methods of stress measurement were used; strain gages and critically refracted longitudinal L CR waves. The material investigated was ASTM...

... stresses of a very thick welded joint by SR treatment. In the first report, an estimating method was developed for relaxation tests, in uniaxial stress state, at changing and constant temperatures because the stress relaxation phenomenon may be considerably similar to that observed in the SR treatment...

... stresses of a very thick welded joint by SR treatment. In the first report, an estimating method was developed for relaxation tests, in uniaxial stress state, at changing and constant temperatures because the stress relaxation phenomenon is considerably similar to that observed in the SR treatment...

... accumulation under the intended loading cycle(s) imposed during future operation. In order to validate the approach, the calculated results were compared to the results of uniaxial stress relaxation testing, bolt model testing, and service experience. The analytical procedure coupled with other industry wide...

... was increased during the second segment. The alloy exhibited about a 95-percent reduction in axial stress (298 to 15 MPa) during shear straining. This reduction was due primarily to plastic coupling, but time-dependent stress relaxation also occurred. A rate-independent plasticity model approximated the stress...

... 12 April 2000 materials testing plastic deformation stress relaxation viscoelasticity plasticity polymers plastics tensile testing Dynamic Stress Relaxation Linear Viscoelasticity Polyethylene Piping Ratcheting Stress Relaxation Thermoplastic Piping Thermoplastics...

...F. V. Ellis; Sebastian Tordonato Analytical life prediction methods are being developed for high-temperature turbine and valve studs/bolts. In order to validate the approach, the calculated results are compared to the results of uniaxial stress relaxation testing, bolt model testing, and service...

... with controlled nominal stress, the maximum local stress at the notch root relaxes; this results in a minimum local stress in compression, and as a consequence, the mean local stress is significantly reduced. The stress relaxation as well as the creep strain accumulation were found to occur only in the vicinity...