Analysis of Tensioning Time for Composite Beam-String Structures Considering Solar Radiation Effects

During the tensioning construction process， the composite beam-string structure is fully exposed to solar radiation. At the moment of structural forming through tensioning， its temperature exceeds ambient levels while demonstrating obvious non-uniformity. In order to clarify the influence of non-uniform temperature effects on the structure’s mechanical properties， a simplified simulation method for non-uniform temperature loads was proposed based on a practical project， and the finite element software ANSYS was used to numerically simulate the structure’s mechanical properties at different tensioning stages under solar exposure. First， field tests and refined numerical simulations were conducted to obtain the temperature distribution patterns along both transverse and longitudinal directions of the top chord composite beam. A temperature gradient model was subsequently established for critical beam sections at various stages. For efficient computation of the beam-string structure considering global non-uniform temperature effects， a quartered beam element simulation method was proposed. Using the finite element software ANSYS， the influence of initial non-uniform temperature fields at different tensioning stages on the structure’s mechanical performance during service life was simulated， and the magnitudes of all mechanical property indicators change in a V shape with the tensioning time. Through a comparison， the optimal tensioning opportunity for the structure was 13：00.