Analytical and Experimental Determination of Mechanical Properties of Irradiated Materials

Abstract

Determination of bulk properties of in-service irradiated material from micro specimen testing is proposed in the work. Due to complex degradation process of aging experimental reproduction of such aging condition is difficult to obtain. Moreover the availability of such aged material is limited due to high cost. Miniaturized specimens are used for this purpose due to many advantages i.e. they can be directly taken out of in-service materials, ease of irradiating using an external source, less dose to personnel during post irradiation testing etc. So both experimental and numerical method is employed to study the aged material response. For numerical analysis, porous solid Gurson-Tvergaard -Needleman model is used and effect of different parameters of G-T-N model is studied. The G-T-N model is calibrated to fit the Stress-Strain curve of unirradiated and irradiated curves and Gurson parameters are found. Effects of irradiation on Gurson parameters are studied. These calibrated Gurson parameters are used to simulate a standard CT specimen. Much experimentation is carried out on fabrication and testing of nonstandard miniature tensile specimen and results are compared with standard sub-tensile specimens (ASTM-370). Proton irradiation of miniature specimen is carried out at DAE facility VECC with irradiation doses of 0.01, 0.02, 0.04 and 0.06dpa. Same methodology is applied to the irradiated specimen to determine their properties to test the correctness of the proposed methodology.