| Popis: |
地震荷重を受ける配管系の弾塑性応答解析の精度や誤差要因を調査するため，既往の試験結果に対 するベンチマーク解析を実施した．ベンチマーク解析は，炭素鋼配管に対する第一段階ベンチマーク 解析およびパラメトリック解析，ステンレス鋼配管に対する第二段階ベンチマーク解析の3種類を実 施した．第一段階ベンチマーク解析の結果より，弾塑性解析結果には降伏応力の設定が大きく影響す る一方，二次勾配の設定や構成則の種別の影響は小さいことが分かった．パラメトリック解析では， 材料特性を二直線近似・移動硬化則に統一し，降伏応力を規格降伏点の1.2倍とすることで，解析によりひずみ範囲を保守的に評価すること，また，解析者間での結果のばらつきが軽減する傾向となることが確認された．第二段階ベンチマーク解析では，ステンレス鋼製のエルボ配管についてある程度の精度で評価できること，ティ配管については形状のモデル化精度が解析結果に影響を与えることが確認された．To investigate the accuracy and the factors that affect elastic-plastic analytical error for piping systems under excessive seismic loads, a series of benchmark analyses on existing experimental results were performed. The benchmark analyses included (1) the first stage of the benchmark analysis on carbon steel pipes (BA_#01), (2) parametric analyses on the same experimental results of the first stage of the benchmark analysis (PA), and (3) the second stage of the benchmark analysis on stainless steel pipes (BA_#02). Based on the BA_#01 results, the setting of the yield stress has a significant effect on the analytical results, whereas the setting of the second inclination of the bi-linear model and the approximation method of the stress-strain curve are not so significant. The PA results revealed that conservative estimation can be accomplished by postulating the bi-linear approximation using a yield stress that is 1.2 times the design yield stress, with the kinematic hardening law as the material property. The PA indicated further that the difference in the analytical results were reduced by unifying the material property. For stainless steel pipes, the BA_#02 results indicated that the inelastic behavior could be well evaluated for elbow pipes, and the modeling accuracy for pipe shape affected the results for tee pipes. |
