Differences in Strength Testing Between Double-Curved GRC Panels and Flat Panels

The strength testing methods for double-curved GRC panels differ significantly from those for flat panels, requiring consideration of the effects of curved surfaces, boundary conditions, and loading methods. Qinglong Group has established a dedicated testing system to ensure the scientific rigor and accuracy of double-curved panel strength evaluation.

Test sample preparation is a key point of difference. Double-curved panels must retain their original curvature during testing; flat-cut specimens cannot be used. Qinglong Group fabricates dedicated test frames to simulate actual support conditions. In the Hainan International Convention and Exhibition Center project, full-scale 1:1 tests were conducted, applying composite loads through a hydraulic servo system to faithfully reflect the stress state of double-curved panels under wind pressure and self-weight. Test data showed that the actual load-bearing capacity of double-curved panels is 15%-20% higher than simplified calculations, providing a more ample safety margin.

Loading methods must simulate real stress conditions. Flat panels mainly bear out-of-plane loads, whereas double-curved panels also experience in-plane stresses. Qinglong Group developed a multi-point coordinated loading system capable of simultaneously applying normal and tangential loads. During testing, panels are first pre-loaded to 1.2 times the service load, stabilized for 10 minutes, and then formally loaded at a controlled rate of 2MPa/min. This testing method accurately reflects the actual performance of double-curved panels under complex stress states.

The criteria for determining failure modes also differ. Failures in double-curved panels often begin at the edges, so dedicated monitoring points must be set up. Qinglong Group employs digital image correlation (DIC) technology to record surface strain distribution throughout the entire process, combined with acoustic emission monitoring, to accurately determine the initial cracking load and ultimate load. These differentiated testing methods provide a reliable basis for the safe application of double-curved GRC panels.