Aim To analyze the working load distribution of complex bolt connection
and to check the bolt fatigue strength of a cylinder head. Methods The finited element the mechanical method are applied to simulate the mechanical load of the bolt. The theory of fatigue strength is used to design the bolt connection. Results The tensile force increment Δ Q of bolts are obtained
and the original structure is proved to be satisfied to the fatigue strength condition. Conclusion The FEM can be used to computed the increment of axial force for complex bolt connection
and with which the ftigue design on bolt can be proceeded.