Non-uniform thermal behavior of single-layer spherical reticulated shell structures considering time-variant environmental factors: analysis and design

Contrary to conventional design methods that assume uniform and slow temperature changes tied to atmospheric conditions, single-layer spherical reticulated shells undergo significant non-uniform and time-variant temperature variations due to dynamic environmental coupling. These differences can affect structural performance and pose safety risks. Here, a systematic numerical method was developed and applied to simulate long-term temperature variations in such a structure under real environmental conditions, revealing its non-uniform distribution characteristics and time-variant regularity. A simplified design method for non-uniform thermal loads, accounting for time-variant environmental factors, was theoretically derived and validated through experiments and simulations. The maximum deviation and mean error rate between calculated and tested results were 6.1 °C and 3.7%, respectively. Calculated temperature fields aligned with simulated ones, with deviations under 6.0 °C. Using the design method, non-uniform thermal effects of the structure are analyzed. Maximum member stress and nodal displacement under non-uniform thermal loads reached 119.3 MPa and 19.7 mm, representing increases of 167.5% and 169.9%, respectively, compared to uniform thermal loads. The impacts of healing construction time on non-uniform thermal effects were evaluated, resulting in construction recommendations. The methodologies and conclusions presented here can serve as valuable references for the thermal design, construction, and control of single-layer spherical reticulated shells or similar structures.