1251 局部減肉がティ配管の低サイクル疲労破損挙動に及ぼす影響(G03-8 材料力学(8)疲労・強度1,21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

抄録

Low cycle fatigue tests were conducted using 65A tee specimens of STS410 with local wall thinning. Local wall thinning was machined on the inside of tee specimens in order to simulate erosion/corrosion metal loss. The local wall thinning areas were located at branched pipes of tee specimens. The tee specimens were subjected to cyclic in-plane bending under displacement control without internal pressure. The effects of eroded conditions, such as location and eroded angle, on the low cyclic fatigue behavior and fatigue life were investigated. Three-dimensional elasto-plastic analyses were also carried out using the finite elements method, which could accurately predict the location of crack initiation and the crack growth direction. In addition, the safety margin of the eroded tee specimens against seismic loading was evaluated comparing the fictitious stress of elbows and the design code.