Abstract: The load critical point is an important factor in the fatigue failure of the truck chassis.Analyzes the critical buckling load of the truck chassis by the arc length method,and tests the two critical types of stainless steel instead of the conventional steel in the critical point of the truck chassis.Finite element software ABAQUS is used to analyze the stress critical point which may cause fatigue failure.The results obtained from the linear analysis of buckling show that the changing material of the chassis does not bring about a large change in the value of the critical load.The results after buckling show that a very small imperfect value results in a significant reduction in critical buckling loads.The experimental results show that the displacement of the pressure point and the magnitude of the stress are very important when the conventional steel is used in the chassis.The displacement of the pressure point and the magnitude of the stress may cause fatigue failure of the chassis and reduce the life of the chassis.

Key words: chassis, arc length method, buckling load, buckling analysis