Technical Principles and Welding Method Selection
The core function of curtain wall connectors is to transfer mechanical effects such as wind loads, seismic forces, and their own weight. Their welding quality directly affects structural safety. Full welding (i.e., complete penetration welding around all four sides) creates a continuous weld, theoretically providing the maximum connection strength, but it is not necessary in all scenarios. For example:
When the force direction is unidirectional: If the connector only bears axial tensile or compressive forces (such as the vertical connection between a column and a transition piece), single-sided or double-sided fillet welds are sufficient. Full welding may, however, lead to material deformation or stress concentration due to excessive heat input.
Dynamic Load Scenarios: In areas prone to wind-induced vibration or earthquakes, a rigid connection with full welding may lead to brittle failure due to a lack of deformation margin. In such cases, a "flexible connection" is needed through partial penetration or intermittent welds to absorb energy and reduce the risk of fracture.
Material Compatibility: Lightweight materials such as aluminum alloys, due to their low melting point and rapid thermal conductivity, are prone to coarse grains in the weld metal when fully welded, reducing corrosion resistance. High-strength materials such as stainless steel, however, require full welding to ensure weld strength matches the base material.
Application Scenarios and Cost-Benefit Analysis
Based on the curtain wall type and project requirements, the choice of welding method must balance safety and economy:
Unitized Curtain Walls: Due to the high degree of prefabrication in the factory, connectors must withstand transportation, hoisting, and long-term loads. Full welding is typically used to ensure structural integrity, but post-processing techniques (such as polishing and anti-corrosion coatings) are necessary to eliminate welding defects.
Framed Curtain Walls: During on-site installation, the connection between transition components and the main structure often uses a hybrid method of bolts and partial welds. This satisfies load-bearing requirements while simplifying the construction process and reducing costs. For example, only critical load-bearing areas (such as the contact surface between corner brackets and columns) are fully welded, while other areas use intermittent welding or spot welding.
Irregularly shaped curtain walls: Due to the difficulty in processing complex curved surfaces or non-standard connectors, full welding may lead to positioning deviations. In this case, high-precision local welding is required through CNC welding equipment, supplemented by reinforcing ribs or reinforcing plates to improve local strength.