Creep-fatigue strength evaluation of perforated plate at elevated temperature using stress redistribution locus method

応力再分配軌跡を用いた有孔平板の高温疲労評価におけるクリープの影響

Bubphachopt, B.*; 渡部 修*; 川崎 信史 ; 笠原 直人

Bubphachopt, B.*; Watanabe, Osamu*; Kawasaki, Nobuchika; Kasahara, Naoto

有孔平板の高温疲労特性に対するクリープの影響を、応力再配分軌跡法(SRL法)を適用し検討した。試験温度は、550Cであり、SUS304製の有孔平板を用いてクリープ疲労試験が実施された。有孔平板は、孔数と孔径をパラメータとした。試験結果は、SRL法と時間消費則を用いて評価した。

This study investigates the effects of creep behavior on fatigue strength of the perforated plate at elevated temperature, when SRL (Stress Redistribution Locus) method is applied for the perforated plate. The creep-fatigue test is carried out by using the specimens made of SUS304 stainless steel at the temperature of 550C. The trapezoidal wave having tensile hold time at peak strain is assumed. The geometry of the perforated plate specimens are changed in the same manner of the fatigue test by number of holes and diameter size of the hole. The linear damage rule for fatigue and creep is assumed, and the comparison between the experimental results and SRL method evaluation at the Coffin diagram will be made. Both of the load and displacement are measured in all the cyclic history of the loadings to clarify the relation between crack initiation/propagation and the load decrease from the direct observation of crack at the holes side.