1) HOWO driving on uneven road frame vertical impact load caused more than frame allowable stress. In addition, in the car on the downhill, cornering or uneven load can also cause to frame local overload frame breaking.
2) frame design or accessory device caused local torque in the frame breaking. If the frame rails of the front cross-section, at the same time due to the engine and transmission, so less distributed beam, which will frame stiffness variation under dynamic loading, may lead to the stringers front fracture, under common stringer wing fracture. In addition, frame by hanging desirability stringer cantilever load (fuel tank, suspension, and spare tire), the local distortions, also contributed to the frame fracture.
3) when the car driving the front wheels on one side by great resistance, so that the frame prone diagonal plane deformation.
4) car collision accident, serious impact will cause the frame deformation
Frame deformation frame to change the original geometry of the assembly parts installed on the frame and make changes in the relative position of the lead drive vehicles deterioration, resulting in the car not running properly. Frame deformation at constant force acting on the frame beyond its elastic limit, after the elimination of the force as used in the frame, the frame can not restitution, the formation of a residual deformation.
1) car stationary or traveling frame under load all over the suspension. Overload driving the frame central force and deformation, resulting in a frame fracture.
2) for the car driven by the rear axle at the start, because the driving force is the upward deflection of the frame central; in the braking of the car, also due to the reaction force of the ground to the wheels (braking force), the frame Central The upward deflection phenomenon goods while filling the frame bending under the frame up and down repeatedly bending, leading to fatigue fracture of the frame.
3) the car overloaded traveling on the level of the great difference in the road, the wheel height is not a plane, causing the frame deformation, is formed when the elastic limit is exceeded, the frame distortions, resulting in residual deformation.
4) traction improper car use, into the pit or the occurrence of a rollover accident, caused by frame deformation General frame of severely deformed visual inspection should be dismantled and plastic for parts re-riveted, or replacement of the frame assembly. Frame after fracture is easier to be seen, should be welded or riveted. Welding should be selected corresponding electrode and the frame material, the operation should be correct to prevent re-fracture.(SINOTRUK)