切欠き領域における弾塑性応力分布の推定

切欠き材における疲労き裂の初期伝播特性(第1報)

抄録

The extension force of short cracks or initial defects existing in the inelastic field of notches can be evaluated by, J-integral. The solution of J-integral may be obtained by interpolation method using elasto-plastic stress. In this case, if the elasto-plastic stress distribution in notch field is estimated by using only elastic solution, then J-integral is calculated by only elastic analysis of components. Thus, in the present report, the distribution of elasto-plastic stresses in notch field were estimated by using elastic solution.
For this approach, strain energy density was taken as the intermediary quantity which connect elastic and elasto-plastic states.
The estimating equations on the intermediary quantity were derived by combining the extending of Neuber's rule and elasto-plastic FEM. The distributions of elasto-plastic stresses were calculated from the strain energy density.
By taking strain energy density as the intermediary quantity, it was able to consider stress redistribution by local yielding, and to consider multiaxial stresses in the notch field.
As a result, equivalent and principal stresses could be estimated with mechanical validity in the inelastic field of notches.