How Should the Thickness of GRC Components at Corners Be Handled? Stress Concentration and Qinglong Group's Structural Reinforcement Techniques

Thickness design at the corners of GRC components must follow the "equal-strength principle": through local thickening or the addition of stiffening ribs, the flexural stiffness of corners is coordinated with that of flat panels to prevent stress concentration from causing cracking. Based on finite element analysis and 28 years of engineering practice, Qinglong Group has summarized corner thickness optimization standards: external corners should use arc transitions (R≥15mm) with thickness increased to 1.2-1.5 times the panel thickness; internal corners require stiffening ribs (height ≥1.5 times panel thickness) or L-shaped integral casting. In the Nanning Wuxiang China Resources MixC project, we applied "R20 arc + gradual thickness transition" (from 20mm to 30mm) to 3,000 window casing corners; after 5 years of temperature-difference cycles, not a single corner crack appeared. Corners are turning points of force and must be treated with exceptional care.

Impact-Resistant Reinforcement Design for External Corners

90° right-angle external corners are vulnerable to impact damage and prone to stress concentration. We adopt dual control measures: geometrically, arc chamfers (R=15-25mm); structurally, local thickening to 1.5 times the panel thickness. For critical areas, diagonal fiber fabric is added at 45° to the corner to improve impact resistance. During mold making, arc transition surfaces are precisely machined by CNC.

Crack-Control Solutions for Internal Corners

Internal corners are high-incidence areas for shrinkage cracking. Three solutions are adopted: integral casting of small components to avoid joints; stiffening ribs for large components (50mm wide, 30mm high); or embedded glass fiber mesh (overlap length ≥150mm). Demolding time is strictly controlled during stripping to avoid early-stage damage.

Specialized Treatment for Irregular Corners

For non-90° corners (such as acute and obtuse angles), finite element analysis is used to determine stress distribution, and radial stiffening ribs are arranged accordingly. In the hexagonal decorative columns of the Shenzhen Yirui project, we adopted an "integral casting + embedded steel skeleton" solution, successfully achieving perfect forming of 20° acute angles.

Waterproofing Detail Considerations

Corners are weak points in waterproofing. Along with thickening, drip edges (10mm wide, 5mm deep) or drainage channels are provided. When sealant is applied to panel joints, ensure it is continuous and full at corners, with sealing strips added if necessary. Our detailed design provides large-scale corner node drawings.

The quality of corner treatment directly reflects a manufacturer's technical strength. Through refined design and manufacturing, Qinglong Group makes every corner an artistic highlight rather than a technical weakness.