アルミニウム合金製構造体の疲労寿命評価
1997 年 35 巻 2 号 p. 58-64
詳細
1997 年 35 巻 2 号 p. 58-64
In order to clarify the fatigue behavior of welded joints connecting an outer plate to the keel of a ship made of JIS A 5083 alloy, constant displacement amplitude fatigue tests of the welded joints (four types) were conducted. Additionally, a finite element method (FEM) analysis and residual stress measurements were carried out. The FEM analysis gave a fairly good estimation of the elastic strain distribution near the toe of the weld. The life evaluation procedure was proposed based on Dowing's stress based approach.
By analysis incorporating quantitatively the effects of stress concentration, welding residual stress and mean stress on the fatigue life of the welded joints, the relationship giving the 95% confidence limits between the equivalent completely reversed stress amplituede σar and cycles to failure Nf was given by the following formula.
σar(MPa)=A⋅NfB: A=702-453, B=-0.17.
This empirical relation appears very useful for designing favorable welded joints for shipbuilding purposes.
