A Comparison of the Simplified Eiastic-Piastic Strain Concentration Factors, K{sub}e, of the ASME Boiler and Pressure Vessel Code with Experimental and Analytical Results

摘要

Low alloy steel laboratory test specimens of two different configurations were cyclically loaded to linearized stress ranges exceeding twice the material yield strength, 2Sy. Strain distributions in the specimens were monitored with strain gages and were correlated with the results of elastic and elastic-plastic finite element analyses. A comparison of the elastic-plastic strain concentration factors determined in this study with the K{sub}e factors specified by the NB-3228.5 simplified elastic-plastic analysis procedure showed the following: (1) At linearized stress ranges exceeding 2Sy, the elastic-plastic strain concentration for both tested configurations fall below the Code K{sub}e factors. (2) Effects of elastic-plastic strain concentration are noted at stress ranges below twice the material yield strength, i.e., at stress ranges where the Code does not specify use of an elastic-plastic strain concentration factor. The significance of the above findings is reviewed relative to potential changes to the Code simplified elastic-plastic analysis procedure.