What are the main reasons for the deformation of aluminum veneer curtain wall

 

Aluminum curtain wall manufacturers Xiaobian summed up the aluminum veneer curtain wall deformation is mainly caused by the following factors:

 

1. The plate has no side ribs and middle ribs, and deformation is caused by wind pressure and air tension.

 

This deformation phenomenon occurs in the use of aluminum-plastic composite panels for the curtain wall. In order to save money, building owners choose irregular manufacturers. In order to obtain higher profits, manufacturers do not use any side ribs or middle ribs. Fold the aluminum-plastic plate into a box shape, screw it directly on the frame with screws, and apply glue to the gap of the plate even if it is completed. In this way, the strength of the curtain wall plate is not enough at all, and the plate will produce inward and outward fatigue deflection deformation under the action of positive and negative wind pressure, which will increase the size of the plate surface. Reflect the more prominent sunny curtain wall, because the construction process is to adopt the form of thermal insulation and warm wall to seal all the plate gaps with glue, the air in the interval between the plate surface and the structural wall heats up under the effect of sunlight, and the plate deforms outward under the action of air tension.

 

2. The plate and the curtain wall structure frame are fixed, and the thermal stress cannot be released to produce deformation.

 

Aluminum curtain wall in the seasonal temperature difference is large, in the early spring and late autumn temperature is low season, when the sun is very strong thermal effect, especially the darker color of the aluminum plate temperature rise is larger, aluminum plate at different temperatures, the thermal expansion value per meter length is larger

 

The curtain wall frame is inside, and the influence of sunlight is weak. When the aluminum plate and the frame are maximum, the temperature difference of more than 80 ℃ can be generated. When the aluminum plate size is large, there will be a large linear expansion difference. If the curtain wall plate structure is folded and the aluminum plate is fixed on the frame with screws, the thermal stress on the aluminum plate surface cannot be released, forcing the plate surface to yield and deform outward under the action of air.

 

This deformation phenomenon is quite large, especially when the curtain wall frame inside the aluminum plate is made of steel, the thermal expansion coefficient of aluminum is generally 2 times that of steel, so the deflection of the same size plate will be 2 times that of the value in the table.

 

The small editor of the aluminum curtain wall manufacturer found that some manufacturers processed the screw holes of the fixed plate into long holes along the length or width direction of the plate on the corner code of the fixed plate, but the plate was still deformed after installation, and this connection method could not meet the requirements of deformation in the curtain wall plane.

 

3. Stress deformation occurs when the panel and the side rib are assembled

 

In order to solve the thermal stress deformation of the aluminum plate plate surface, especially when the panel adopts aluminum-plastic composite plate, some manufacturers add a ring of edge rib frame around the unit plate. From the production process, the panel is planed and folded into a box shape according to the folding size of the plate on the planer. The other line is to cut the edge rib profile according to the required size of the plate to assemble the edge rib frame. Then the edge rib frame is installed into the box-shaped panel, and the two bodies are fixed with blind rivets.

 

At the work site, it is often found that due to the deviation of the folding edge of the panel planing groove and the deviation of the side rib profile assembly into the frame, the two bodies often match each other, either the frame is small or the plate folding edge size is too large. In order to ensure the construction period and free of material cost, assembly is often forced, resulting in assembly stress on the board surface, either deformation of side ribs or compression deformation of the board surface. This plate produces outward deformation under the action of temperature and air expansion forces.