Calculation Method Based on Equivalent Sandwich Plate Method for deflection of Space Frame Structures under Elevated-Temperature Uniform Temperature Field

The Equivalent Sandwich Plate Method (ESPM) is widely employed in structural engineering for space frames due to its high accuracy under room temperature conditions.However, the precision of ESPM calculations diminishes at elevated temperatures, primarily due to increased static indeterminacy and substantial restraint stress on rods caused by thermal expansion.Additionally, the decrease in the elastic modulus of steel leads to significant changes in mechanical properties.This research focuses on various sizes and the overall compliance of regular square pyramid space frame structures, where the overall compliance is defined as the ratio of the central deflection at room temperature to the long span length of the space frame structure.A new deflection formula for ESPM under high temperatures is derived, considering the mechanical and thermal properties of steel.The finite element software is utilized to simulate the deformation of the space frame.Through the calculation of the ratio of Finite Element Method (FEM) results to ESPM, a series of correction coefficients is obtained to enhance the accuracy of ESPM.