A modified small punch testing scheme to investigate the circumferential mechanical behavior of nuclear fuel cladding tubes

Abstract

The manufacturing process of nuclear fuel cladding tubes endows them with anisotropic material properties. In this study, a small punch testing (SPT) method was established to investigate the circumferential tensile behavior of nuclear fuel cladding tubes. The specimen of the proposed SPT method was bended and stretched in a single stress state under a punching force. The proposed SPT method was then used to analyze the circumferential tensile behavior of a FeCrAl fuel cladding tube. Finite element simulation results indicated that the SPT method established herein determined ultimate tensile stress with higher accuracy than standard SPT because the plastic strain in the proposed method under maximum force is considerably smaller than that in standard SPT. Moreover, the proposed method can more accurately determine yield stress compared with standard SPT, as reflected by the elastic stage in the load–displacement curve that was a straight line. The test results indicated that the proposed SPT can be used to accurately determine the circumferential yield stress and ultimate tensile stress of nuclear fuel cladding tubes.