Abstract:

In order to quantitatively study crankshaft fatigue life repaired by arc spraying, the tensile test of the 48MnV with 3Cr13 coatings is conducted, the method proposed by Baumel Jr. and Seeger is used to estimate fatigue parameters of the material. And the fatigue life of crankshaft repaired arc spraying is calculated and assessed. The loads in each link neck are obtained through dynamic simulation, among which spring units are used to simulate the actual elastic support status in the spindle neck and the boundary conditions are adjacent cranks interaction. Then, the Crankshaft fatigue life is calculated using multiaxial damage model, respectively using the normal strain law, the SWT-Bannantine approaches, shear strain method and Fatemi-Socie method. Finally, the engine bench strengthen tests of the new axis, respectively 500 h, 1 000 h and 3 000 h are conducted. And the crankshaft after the engine bench strengthen test is cut into cranks on which the fatigue tests are carried out. The test results match the cal- culation results.

Key words: mechanical design, crankshaft, arc spraying, dynamic simulation, Finite Element, multiax- ial fatigue life