Research on Out-of-Plane Mechanical Performance of Prefabricated Sandwich Insulated Wall Panels with FRP Plate Connectors

To investigate the out-of-plane flexural behavior and the influence of key design parameters of prefabricated sandwich insulated wall panels incorporating FRP plate connectors， a full-scale specimen was designed and tested under monotonic static loading. A refined nonlinear finite element （FE） model was developed using the ABAQUS platform. The accuracy of the FE model was validated by comparing the failure modes， load-displacement responses， and crack propagation processes with experimental observations. On this basis， a parametric study was conducted to evaluate the effects of insulation layer thickness， connector spacing， and concrete strength on the structural performance. The results indicated that the proposed FE model accurately reproduced the “X”-shaped yield line failure pattern and the overall load-bearing mechanism of the wall panel. Increasing the insulation layer thickness significantly reduced structural stiffness； an increase from 100 mm to 200 mm resulted in a 26.4% decrease in bearing capacity. Connector spacing had a pronounced impact on bearing capacity： as the spacing increased from 400 mm to 600 mm， the composite action between layers weakened substantially， leading to an ultimate bearing capacity reduction to 219.21 kN. Furthermore， increasing the concrete strength effectively improved both the stiffness and bearing capacity.