How to optimize the process path to reduce stress concentration in the combined welding and bending process of structural sheet metal parts?
Publish Time: 2026-05-20
In modern high-end equipment manufacturing and industrial structural design, structural sheet metal parts are widely used in mechanical equipment, automated devices, and industrial frame systems due to their lightweight, high strength, and good machinability. In actual production, the combined welding and bending process is one of the most common forming methods. However, this process is prone to residual stress concentration, which affects structural stability and service life.
1. Optimize the bending sequence to reduce initial stress accumulation
In the sheet metal structure forming process, the rationality of the bending sequence directly affects the internal stress distribution of the material. An improper bending sequence can easily lead to local deformation superposition, forming stress concentration areas. Therefore, in the process design stage, it is necessary to analyze the structural stress through 3D modeling and rationally plan the bending path. Adopting an inside-out or symmetrical bending sequence can effectively disperse the material deformation stress, ensuring the overall structure maintains a uniform stress state during forming, reducing the risk of subsequent welding stress superposition from the source.
2. Optimize the welding path to reduce thermal stress concentration
The welding process is one of the main sources of thermal stress. An improperly designed welding path can lead to excessively high local temperatures, resulting in significant thermal deformation and residual stress. Therefore, optimizing the welding sequence, such as using segmented skip welding or symmetrical welding, can effectively control heat input distribution, ensuring uniform heat diffusion and reducing localized overheating. Simultaneously, rationally controlling welding speed and current parameters can reduce the heat-affected zone, thereby minimizing welding stress concentration.
3. Introducing Staged Processing for Stress Release
In combined welding and bending processes, continuous processing easily leads to stress accumulation, while staged processing helps release stress. For example, after initial bending, intermediate annealing or natural aging treatment can partially release the internal stress of the material before proceeding with subsequent welding processes. This staged process path not only reduces residual stress accumulation but also improves overall structural stability, making the finished product less prone to deformation during long-term use.
4. Optimizing Structural Design to Reduce Stress Concentration Points
Structural design itself has a decisive influence on stress distribution. If the design contains sharp corners, abrupt changes, or discontinuous structures, stress concentration is likely to occur during welding and bending. Therefore, during the structural design phase, rounded corner transitions, uniform wall thickness, and continuous load-bearing structures should be adopted as much as possible to improve stress distribution. Simultaneously, adding stiffeners or optimizing the support structure can effectively disperse loads and improve overall deformation resistance.
5. Optimizing Process Paths Through Simulation Analysis
With the development of digital manufacturing technology, finite element simulation has become an important tool for optimizing sheet metal process paths. In the welding and bending process design phase, by simulating the material's stress and thermal deformation process, potential stress concentration areas can be identified in advance, and the processing path can be adjusted accordingly. This simulation-based process optimization method not only improves design accuracy but also significantly reduces prototyping costs and increases production efficiency.
Overall, in the combined welding and bending process of structural sheet metal parts, effective control of stress concentration requires comprehensive improvements in multiple aspects, including bending sequence optimization, welding path design, staged processing, structural design optimization, and simulation analysis. Through systematic process path optimization, residual stress can be significantly reduced, structural stability and service life can be improved, and sheet metal structural parts can better meet the needs of high-strength industrial applications.
