Report on FY17 testing in support of integrated EPP-SMT design methods development

Wang

et al. 2019

Section: Overviewmentioning

confidence: 99%

Section: Scaling Directly From Experimental Datamentioning

confidence: 99%

Initial Development of an Improved Creep-Fatigue Design Method that Avoids the Separate Evaluation of Creep and Fatigue Damage and Eliminates the Requirement for Stress Classification

Messner

Wang

et al. 2019

“…The testing parameters and the results of these two tests are highlighted in Table 1 and Table 2 along with previous pressurized SMT results for comparison. The details of the test procedures and results are described in [7]. The combined tension and compression tests lasted longer than the comparable tension only tests.…”

Section: Pressurized Smt Testsmentioning

confidence: 99%

“…Two-bar thermal ratcheting tests were performed on 316H stainless steel to assess the material response to cyclic thermal loading under two-bar testing conditions at the intermediate temperature range of 405 to 705 0 C. The details of the test procedures and results are described in [7].…”

Section: Two-bar Testsmentioning

confidence: 99%

Report on an Assessment of the Application of EPP Results from the Strain Limit Evaluation Procedure to the Prediction of Cyclic Life Based on the SMT Methodology

Messner

Sham

et al. 2017

Self Cite

The goal of the proposed integrated Elastic Perfectly-Plastic (EPP) and Simplified Model Test (SMT) methodology is to incorporate an SMT data based approach for creep-fatigue damage evaluation into the EPP methodology to avoid the separate evaluation of creep and fatigue damage and eliminate the requirement for stress classification in current methods; thus greatly simplifying evaluation of elevated temperature cyclic service. This methodology should minimize over-conservatism while properly accounting for localized defects and stress risers. To support the implementation of the proposed methodology and to verify the applicability of the code rules, analytical studies and evaluation of thermomechanical test results continued in FY17. This report presents the results of those studies. An EPP strain limits methodology assessment was based on recent two-bar thermal ratcheting test results on 316H stainless steel in the temperature range of 405 to 705 0 C. Strain range predictions from the EPP evaluation of the two-bar tests were also evaluated and compared with the experimental results. The role of sustained primary loading on cyclic life was assessed using the results of pressurized SMT data from tests on Alloy 617 at 950 0 C. A viscoplastic material model was used in an analytic simulation of two-bar tests to compare with EPP strain limits assessments using isochronous stress strain curves that are consistent with the viscoplastic material model. A finite element model of a prior 304H stainless steel Oak Ridge National Laboratory (ORNL) nozzle-to-sphere test was developed and used for an EPP strain limits and creep-fatigue code case damage evaluations. A theoretical treatment of a recurring issue with convergence criteria for plastic shakedown illustrated the role of computer machine precision in EPP calculations.

“…A detailed plan has been developed and revised for the development of this EPP+SMT methodology (Wang et al, 2016a, 2016b, 2017a, 2019. The development of SMT-based design curves requires experimental data, and the parameters to be considered include elastic follow-up factor, strain range, loading rate, test temperature, hold time, and primary load.…”

Section: Introductionmentioning

confidence: 99%

Support of the Development of EPP Plus SMT Design Method (FY2020 Test Results)

Wang

Hou

et al. 2020

Self Cite