Development of triaxial tension creep test machine
Mukai Shoichi; Komatsu Yasuhiro; Ueda Daisuke; Sakane Masao; Ohnami Masateru; Tsurui Takasfumi
Abstract:This paper describes the development of triaxial tension creep machine. The developed machine can make equi-triaxial tension creep experiments, and has a loading capacity of 49 KN and the maximm temperature of 923 K. Three dimensional finite element (FE) elastic-creep analyses were made to determine the shape and dimension of the specimen having uniform equi-triaxial stress distribution at the specimen center. The specimen shape determined by the FE analyses has 2.0 mm groove radius at the notch. Equi-triaxial tension creep test was performed using Type 304 specimen at 923 K. The uniaxial, equi-biaxial and equi-triaxial tension creep lives of Type 304 stainless steel at 923 K were compared. Creep rupture time increased with increasing J1 ( = sx + sy + sz), so that the positive mean stress has an effect of increasing the rupture time. In the equi-triaxial tension stress condition, three principal strains of ex, ey and ez were smaller than in the uniaxial tension and equi-biaxial tension stressing conditions. Key Words:triaxial stress, high temperature, creep, rupture time, creep curve