Causes of single point suspension damage

1. Brittle fracture and ductile fracture

When the parts bear the external load, the first elastic deformation occurs. When the stress caused by the load exceeds the elastic limit and continues to increase, the parts undergo plastic deformation. When the stress exceeds the strength limit, the axle of the semi-trailer breaks. This kind of fracture is called ductile fracture. The fracture of ductile fracture has obvious plastic deformation, the color is gray, and sometimes obvious fibrous shape can be seen.

2. Residual stress

When the trailer axle parts are subjected to external load, the internal stress, that is, normal stress and shear stress, will occur. When the external force is removed, the stress remaining in the parts is called residual stress. The residual stress will lead to brittle fracture and additional plastic deformation of the parts. This situation is especially easy to occur in the castings such as cylinder block and transmission housing, not only during casting, It also happens in the use phase.

3. Stress concentration

If there are discontinuities in the geometry of the parts, such as material defects, the actual stress near these parts is much higher than the nominal stress, and the stress concentration is suppressed. Cracks are most likely to occur at the stress concentration, which can not be ignored in the fracture observation and analysis of parts.

4. Fatigue fracture

According to the load nature of the parts, the fracture can be divided into one loading fracture and repeated loading fracture; Repeated loading fracture, also known as fatigue fracture, is the fracture of axle parts of semi-trailer after repeated stress or load. https://www.chinaaxle.cn