Estimation of transverse tensile behavior of Zircaloy pressure tubes using ring-tensile test and finite element analysis

Abstract

Determination of transverse mechanical properties from the ring type of specimens directly machined from the nuclear reactor pressure tubes is not straightforward. It is due to the presence of combined membrane as well as bending stresses arising in the loaded condition because of the curvature of the specimen. These tubes are manufactured through a complicated process of pilgering and heat treatment and hence, the transverse properties need to be determined in the as-manufactured condition. It may not also be possible to machine small miniaturized specimen in the circumferential direction especially in the irradiated condition. In this work, we have performed ring-tensile tests on the un-irradiated ring tensile specimen using two split semi-cylindrical mandrels as the loading device. A three-dimensional finite element analysis was performed in order to determine the material true stress–strain curve by comparing experimental load–displacement data with those predicted by finite element analysis. In order to validate the methodology, miniaturized tensile specimens were machined from these tubes and tested. It was observed that the stress–strain data as obtained from ring tensile specimen could describe the load–displacement curve of the miniaturized flat tensile specimen very well. However, it was noted that the engineering stress–strain as directly obtained from the experimental load–displacement curves of the ring tensile tests were very different from that of the miniaturized specimen. This important aspect has been resolved in this work through the use of an innovative type of 3-piece loading mandrel.

Pengaruh Hidrogen Terhadap Kekuatan Tarik Kelongsong Bahan Bakar Nuklir Berbasis Paduan Zirkonium

“…Desain perlengkapan uji tarik ini berupa mandrel setengah lingkaran dari diameter material uji seperti yang terlihat pada Gambar 1. Perlengkapan uji tarik ring dapat berupa dua mandrel setengah lingkaran yang dipasangkan pada grip seperti dalam ASTM D2290 [9,13] atau dua pin setengah lingkaran yang terpasang pada grip. Pengujian tarik ring menggunakan mesin uji tarik Shimadzu AGS-X dengan beban 10 kN dan laju penarikan sebesar 1 mm/s pada temperatur kamar.…”

Mechanical anisotropy in ultra-fine grained aluminium tubes processed by parallel-tubular-channel angular pressing

“…He et al [10] took hoop tension check and investigated the mechanical properties and also formability of AZ31B in extruded tube at accelerated temperatures. As it is shown in Samal et al [11], the transverse tensile conduct of zircaloy tube was presented using the ring tensile test. Tavakkoli et al [12] investigated anisotropic properties of Cu–Zn tubes through the parallel tubular channel angular pressing (PTCAP) process.…”