How Does Strength Testing of Double-Curved GRC Panels Differ from Flat Panels? Spatial Mechanics and Qinglong Group's Specialized Testing System

The strength testing methods for double-curved GRC panels differ fundamentally from those for flat panels, requiring a specialized testing system built on four levels: specimen sampling, loading methods, evaluation criteria, and safety reserves. Flat panel testing typically employs simply supported bending tests, while double-curved panels must account for the spatial load-bearing characteristics of curved shells. Qinglong Group, in collaboration with multiple research institutions, has developed a specialized testing method for double-curved panels combining "full-scale model testing + digital simulation": vacuum attachment loading simulates wind pressure, fiber Bragg grating sensors measure surface strain distribution, and finite element analysis is applied for safety assessment. In verification at the Hainan Convention and Exhibition Center project, the actual load-bearing capacity of double-curved roof panels reached 3.5 times the design value, far exceeding the 2.0 safety factor of flat panels. Curved surface strength testing requires breaking away from flat-plane thinking.

Specimen Sampling and Boundary Condition Simulation

Double-curved panels must be tested using full-scale or large-scale specimens to ensure boundary conditions are consistent with the actual installation state. We fabricate 1:1 test units with complete connection joints, mounted on rigid frames to simulate actual support conditions. Before testing, 3D scanning precisely measures the specimen's geometry as an analysis baseline.

Spatial Loading and Measurement Techniques

A multi-point synchronous loading system applies uniformly distributed loads on the curved surface through airbags or actuators. 3D Digital Image Correlation (DIC) is used for full-field deformation measurement, combined with fiber optic sensors to monitor strain at key points. This testing method was used in the Nanning New Media Center project, successfully capturing the unique "membrane effect" of double-curved panels.

Failure Modes and Safety Evaluation

Double-curved panel failure often begins at edges or connection points, manifesting as local crushing rather than overall bending failure. We have established a dual evaluation standard based on maximum strain and deformation limits, which better reflects the actual load-bearing characteristics of curved structures. Acoustic emission technology monitors internal damage development, enabling failure warning.

Digital Twin and Safety Warning

High-precision finite element models, calibrated with test data, are used to assess safety under different load conditions. In the Shenzhen Yirui project, we used digital twin technology to predict stress distribution under typhoon conditions, providing a basis for design optimization. This "testing + simulation" approach has become our standard verification process for double-curved panels.

Strength testing of double-curved GRC requires more scientific methods and a more comprehensive perspective. Through innovative testing technology, Qinglong Group provides reliable assurance for the safe application of curved structures.