The plate has no side ribs and middle ribs, and is deformed by wind pressure and air expansion.

1. The plate has no side ribs and middle ribs, and is deformed by wind pressure and air expansion. This "bulging" phenomenon often occurs on curtain walls that use aluminum-plastic composite panels as panels. In order to save money, building owners choose informal manufacturers. In order to obtain higher profits, manufacturers do not use any side or middle ribs. Fold the aluminum-plastic plate into a box shape, screw it directly to the frame with screws, and put glue on the gaps between the plates. In this way, the strength of the panels of the curtain wall is simply not enough. Under the action of positive and negative wind pressure, the panels produce fatigue deflection deformation inward and outward, causing the panel size to increase. The curtain wall reflects the more prominent sunny side. Because all the gaps between the panels are sealed with glue according to the construction technology of the thermal insulation wall, the air in the space between the panels and the structural wall heats up under the sunlight effect, and the panels "bulge outward" due to the expansion of the air. "Transformation. 2. The plates are fixed to the curtain wall structural frame, and thermal stress cannot be released to cause deformation. Aluminum panel curtain walls are used in areas with large seasonal temperature differences. In the seasons of early spring and late autumn when temperatures are low, the thermal effect of sunlight is very strong. In particular, darker aluminum panels heat up more. The thermal expansion value is large: the curtain wall frame is inside, and the influence of sunlight is weak. The temperature difference between the aluminum plate and the frame can be more than 80°C. When the size of the aluminum plate is large, a large linear expansion difference will occur. If the curtain wall panel structure uses hemming and the aluminum plate is fixed to the frame with screws, the thermal stress on the aluminum plate surface will not be released, forcing the plate surface to yield, and a "bulge" phenomenon will appear outward under the action of air. This "bulging" phenomenon is quite large as shown in Table 2, especially when the curtain wall frame inside the aluminum plate uses steel profiles. Since the thermal expansion coefficient of aluminum is generally twice that of steel, the deflection produced by the same size plate will be as shown in Table 2. 2 times the median value. The author found that some manufacturers process the screw holes of the fixed plate into long holes on the ears of the fixed plate along the length or width direction of the plate. However, the "bulge" phenomenon still occurs after the plate is installed, and this connection method cannot achieve Requirements for in-plane deformation of curtain walls. 3. Assembly stress deformation occurs between panels and side ribs. In order to solve the thermal stress deformation of aluminum plate panels, some manufacturers add a circle of side ribs around the unit panel, especially when the panels are made of aluminum-plastic composite panels. In terms of technology, the panel is grooved and folded into a box shape on a router according to the plate folding size. The other line is to cut the side rib profiles according to the required size of the plate and assemble them into a side rib frame. Then the side 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 the panel is grooved and folded with deviations, and the side rib profiles are assembled into frames with deviations. When the two bodies are matched, it is often found that either the frame is too small or the panel folding size is too large. In order to ensure the construction period and save materials, assembly is often forced, causing assembly stress on the board surface, either the side ribs are deformed or the board surface is deformed under pressure. This kind of plate "bulges" outward under the action of temperature and air expansion.