The performance differences of different materials (such as steel and aluminum alloy) under wind loads are mainly reflected in the elastic modulus, stiffness, bearing capacity, wind resistance and weight, as follows:

1. Elastic modulus and stiffness

The elastic modulus of steel is significantly higher than that of aluminum alloy, about 3 times that of aluminum alloy. This means that under the same span and cross-section conditions, the stiffness of steel is 1/3 of that of aluminum alloy, and it is less prone to deformation.

The lower elastic modulus of aluminum alloy makes it more susceptible to elastic deformation under wind loads, but its lightweight properties can reduce the wind load effect of the overall structure.

2. Bearing capacity

The ultimate bearing capacity of steel is much higher than that of aluminum alloy. For example, under the same load conditions, the ultimate bearing capacity of steel is 6.9 kN/cm, while that of aluminum alloy is 3.7 kN/cm. In addition, the tensile strength (at least 600 N/mm²) and fracture stress (490-790 N/mm²) of steel are higher than those of aluminum alloy (tensile strength 220-470 N/mm², fracture stress 540 N/mm²).

The reduction in the bearing capacity of aluminum alloy under wind loads needs to be considered. For example, when a structural component is directly subjected to wind loads, its bearing capacity needs to be reduced to 67% of the original value.

3. Wind resistance

Steel performs better in strong wind areas due to its high stiffness and strength. For example, a steel photovoltaic support system can remain stable under wind speeds of 0.3 kN/m². In addition, the compressive strength of steel (490-790 N/mm²) is higher than that of aluminum alloy (220-470 N/mm²), making it suitable for structural design in high wind speed areas.

Aluminum alloy is prone to wind vibration under wind loads due to its lightweight characteristics, and Aluminum Alloy Photovoltaic Bracket stability needs to be enhanced by increasing the density of fixing points or using wind-resistant clamps (such as foam strips).

4. Weight and cost

The density of aluminum alloy is only 35% of that of steel, so it is lighter, but the cost is three times that of steel at the same weight. The lightweight property can reduce the dynamic impact of wind load on the structure, but additional design is required to compensate for the lack of strength.

Steel is heavier, but its high load-bearing capacity and wind resistance make it more advantageous in strong wind areas

5. Durability and environmental adaptability

Steel needs to rely on anti-corrosion treatment (such as hot-dip galvanizing or spraying) to resist corrosion, while aluminum alloys form a dense oxide film in the air, which has natural corrosion resistance. However, aluminum alloys may affect performance due to creep effects at high temperatures (300°F-900°F).

Steel has better stiffness, load-bearing capacity and wind resistance under wind load, and is suitable for strong wind areas or high wind speed environments; aluminum alloy is suitable for low wind speed or weight-sensitive scenes due to its light weight and low cost, but it needs to improve its wind resistance through design optimization (such as adding fixing points and wind-resistant clamps)