초 임계 압력 보일러에 적용되는 압력조절밸브의 셰이크다운 탄성 한계 해석 및 규명

This study presents the shakedown limit boundaries of a pressure-reducing valve (PRV) subjected to complex cyclic thermomechanical loadings using the linear matching method (LMM). The thermomechanical loadings are composed of three cyclic bending moments (in-plane, out-of-plane, and torsional), two cyclic internal pressures (high and low), and cyclic thermal loads (temperature gradients). The analysis results reveal that the PRV has a shakedown limit boundary that is identical to the plastic collapse limit. Comprehensive numerical parametric studies were also conducted to assess the effects of individual cyclic bending moments on the cyclic plastic behavior of the PRV, and the results showed that the in-plane cyclic bending moment significantly impacted the structural integrity of the PRV compared to other bending moments.