Development of thermomechanical design methods for smooth structures, 3; Development structural analysis methods

Autor: Kasahara, Naoto, Garatani, Kazuteru
Jazyk: japonština
Rok vydání: 1993
Zdroj: PNC TN9410 93-184.
Popis: 構造解析に使用する物性値の温度依存性とひずみ集中評価法が平滑部材熱過渡強度評価結果に及ぼす影響を調べた。物性値の温度依存性は,温度上昇と共に応力を下げる方向に変化するが,その大きさは2\%以内で大きくはないことを明らかにした。歪み集中評価法に関しては熱過渡時の歪み挙動に大きな影響を与える(1)熱ピーク応力,(2)ポアソン比効果,(3)材料非線形性およびこれらの重畳効果と,歪み集中の程度を表わす弾性追従パラメータの関係を以下のように調べ,熱過渡強度評価に使用するための歪み集中の評価法を提案した。
Temperature dependency of material properties for structural analysis and strain concentration evaluation methods have influences on thermal transient strength evaluation result, and those effects were investigated. It appeared that temperature dependency of material properties has small influences. On the strain concentration evaluation method, effects of (1) thermal peak stress, (2) Poisson's ratio, and (3) Nonlinearity of materials on strain concentration, a degee of which is described by elastic follow-up parameters, were evaluated as follws, (1) Relations between thermal peak stresses and elastic follow-up parameters [peak stress index $\nu$=0.499 $\nu$=0.3] [Tn=1.5, 1.48, 1.04] [Tn=2.0, 1.54, 1.08] [Tn=2.5, 1.57, 1.11] [Tn=3.0, 1.58, 1,12] [Tn=5,0, 1.58, 1,12] (2)An elastic follow-up parameter for Poison's ratio [$\nu$=1.4] (3)Relations between nonlinearity of materials and elastic follow-up parameters [stress-strain index, elastic follow-up parameter] [N=3, 1.539] [N=5, 1.578] [N=7, 1.603] (4)If peak stress and Poison's ratio effect are overlapped, elastic follow-up parameters are multiplied. The following strain concentration factor is proposed, though this study. [$\varepsilon$t=K$\varepsilon$($\varepsilon$n+$\varepsilon$F)] [K$\varepsilon$=1+(q-1) {1-$\sigma$$_{y}$/(Sn+SF)}, q=5/3] where $\varepsilon$n+$\varepsilon$F: elastic analysis result, $\varepsilon$t: slastic-plastic strain, K$\varepsilon$:strain concentration factor.
Databáze: OpenAIRE