What are the symptoms of frame deformation?

[McLane]

The symptoms of frame deformation include bending, partial fractures, tilting, local depressions, and bulges in the frame. Causes of frame deformation: 1. The bending moments acting on the frame's longitudinal beams are not always applied along the bending centerline of the beam's channel-shaped cross-section, resulting in both bending and torsional stresses in the longitudinal beams. 2. When driving on rough roads, the reaction forces from the road surface transmitted through the leaf springs force the frame to undergo torsional deformation. 3. When the vehicle's wheels encounter obstacles, the longitudinal beams of the frame tend to displace horizontally under the applied forces. 4. During turns, centrifugal forces can also cause the longitudinal beams to twist and tilt.