High temperature environmental impact of steel structure grid processing

High temperature environmental impact of steel structure grid processing

Introduction to Steel Structure Grid: At room temperature, due to the regular form of steel structure grid processing building space grid structural units, tight spatial connections, good overall stability, and no overall collapse due to local member damage. However, under high temperature conditions, the grid members will expand due to the increase in temperature, and the mechanical performance and structural stability will change.

1. Temperature field factors

The location and propagation path of a fire have a significant impact on the distribution of temperature field, and temperature directly affects material properties. Due to the fire burning along the external decorative materials, the temperature of the outer grid is higher than that of the inner grid, and the temperature of the right edge member is higher than that of the mid span member. This results in a larger internal force value for the member at the outer edge of the right side.

2. Material factors

The increase in temperature leads to a significant decrease in the stiffness and strength of the material. Under the same load, a decrease in stiffness will increase the deformation of the member, while excess deformation will increase the additional internal force of the member.

3. Constraint reasons

The temperature effect cannot be ignored in the processing of steel structure grids for statically indeterminate structures. For the members in the middle of the structure, due to weak support constraints, they can have a certain degree of expansion and contraction under temperature. And this will reduce the increase in the additional internal force of the rod, and the material will also reduce the impact of excess internal force.

The members near the support at the edge of the grid frame have a large constraint stiffness. During the expansion process of the steel structure grid frame processing building members, they cannot be released through expansion and contraction, which will cause the internal force of the member section to continue to accumulate, resulting in excessive local stress. This causes some members connected to fixed supports to experience excessive deflection values, which seriously affects the local bearing capacity of the grid structure.