With the rapid development of industry, the application of ultrasonic welding machines is more and more extensive. I believe that everyone has a certain understanding of the structure of the ultrasonic welding machine, so what is the problem with the ordinary ultrasonic welding structure? Next, Xiaobian will help you answer this question.
1. Stress concentration
The stress concentration of the welded structure includes weld defects in the weld toe, weld root and joint area. Stress concentration and structural stress concentration caused by structural cross-section mutations. If there is a welded joint at a sudden change in the structural section, the stress concentration will be more serious. Stress concentration has a large effect on the brittle fracture and fatigue strength of the structure. The stress concentration of the welded structure is controlled by a reasonable structural design and process.
2. Welding stress and deformation
Since the welding process is localized, internal stresses are inevitably generated and Deformation. If a large tensile stress occurs during heating, it will cause weld cracks or cracks. The residual stress after welding has a great influence on the strength, stiffness, stability and dimensional accuracy of the structure.
3. Uneven solder joint performance
Welded joint is a joint body with uneven structure and properties. There are different degrees of mismatch in the weld, heat affected zone and the toughness of the parent metal. This mismatch has an important influence on the strength and fracture properties of the entire structure and is an important factor to be considered in the evaluation of the use of welded structures.
4. Strong overall, enhanced structural steel
The integrity of the welded structure gives the structure a good watertight Sex and air tightness, but it also brings some problems. The integrity improves the rigidity of the structure and increases the sensitivity to stress concentrations. Due to its strong integrity, it is difficult to prevent crack propagation once cracks occur and expand. In a riveted structure, if a crack occurs and expands, the crack will extend to the edge of the sheet and the rivet hole, thereby terminating. The riveted joint acts to limit the continued expansion of the crack.
5. Welding defect
Rapid heating and cooling during the welding process makes the local material in very unbalanced conditions Lower melting, solidification and solid phase transformation. Welding defects such as cracks, pores, impermeability, and slag inclusions often occur in the weld zone. Welding defects are often the source of structural damage. Therefore, the detection and identification of welding defects in welding production is an important means to ensure the quality of welding. In the welding process, in order to ensure the integrity of the welded structure, it is very important to monitor and evaluate the defect behavior.