Numerical and Thermodynamic Study on the Prefabricated Double Steel Plate Composite Shear Wall Enclosure

Lateral force resistance of prefabricated double steel plate composite(DSPC) shear walls has been well characterized. However，local low-temperature areas can form easily，leading to condensation and mold due to numerous internal high thermal conductivity components and causing an uneven heat transfer. To address this issue，a class of enclosure prototypes was proposed based on the optimization of the thermal properties of a prefabricated DSPC shear wall enclosure. A finite element model was established using COMSOL Multiphysics combined with a parametric sweep to investigate the effects of thermal insulation and structural connectors on heat flux patterns in DSPC shear walls. The results demonstrated the following：the cold spots generated by insulation anchor bolts are considerably larger than those induced by tie bolts，and no significant temperature fluctuation exists at the plug-welded connection of the double steel plates；the connectors penetrating multiple structural layers must be spaced properly to prevent heat flux release without insulation. Compared with the ideal model neglecting thermal bridging，the total normal heat flux per unit area of the actual bridging is always greater. Employing insulation materials with low thermal conductivity reduces heat flux through the main section considerably；however，a limited inhibition effect is observed at cold spots. As the thermal conductivity of the insulation drops，the gradient of heat flux reduction rises，and utilizing fireproof rock wool or insulated EPS is recommended as an optimal choice in terms of technical economy. The normal heat flux can be effectively suppressed by thickening the insulation layer；however，this effect weakens as the insulation thickness increases. Based on the eligible structural properties，priority must be given to widening the spacing of the structural connectors while reducing the anchorage depth for a uniform internal temperature and then switching to well-insulated FRP connectors，and finally，adding an insulation mortar or bedding at the anchorage end to reduce the impact of thermal bridging. This study can guide the thermal design of prefabricated DSPC shear wall structural systems by providing the variation patterns of normal heat flux regarding thermal-dependent parameters in the insulation layer and structural members. © 2023 Tianjin University. All rights reserved.