How to Analyze Force Flow Distribution in Double-Curved GRC Shapes? Structural Rationality and Qinglong Group's Computational Simulation Technology

Force flow distribution analysis of double-curved GRC forms is a key technology for revealing their intrinsic mechanical logic and achieving the unity of safety and economy. It requires computational tools such as finite element simulation, the dynamic relaxation method, and topology optimization to translate intuitive forms into quantifiable stress contours and deformation fields. In the design of the super-large double-curved roof (120,000 ㎡) at the Hainan International Convention and Exhibition Center, Qinglong Group carried out refined finite element analysis using ANSYS software, simulating the stress distribution and force flow paths inside the shell under combined wind, snow, self-weight, and temperature loads. Based on this, the panel thickness (graduated from 25mm to 18mm) and stiffener layout were optimized, saving more than 20% of material while ensuring safety (maximum stress ≤ 5MPa). Only by reading the force flow can one master the form.

The Finite Element Method Is the Core Tool for Refined Analysis

We establish an integral finite element model that includes the double-curved GRC shell, stiffening ribs, embedded parts, and supporting structure. The shell is simulated with shell elements (Shell 181), which accurately reflect in-plane and out-of-plane forces. Loads are applied according to the most unfavorable combinations, and the response under static and dynamic actions (such as wind-induced vibration) is analyzed. Through computation, one can intuitively see how the force flow starts from the points of load application, travels along the stiffer paths (i.e., the "force flow") toward the supports, and where stress concentrations arise.

The Dynamic Relaxation Method for Form-Finding

For projects that require the proactive design of efficient load-bearing forms (such as free-form curved shells), we adopt form-finding techniques such as the dynamic relaxation method. This method simulates the equilibrium shape of a cable net or membrane structure under prestress, and infers in reverse its "inverse model"—an efficient shell form that carries mainly compression. The resulting form is inherently a rational load-bearing shape with the highest material utilization. In the design of an art museum in Nanjing, we generated a lightweight yet stable double-curved thin shell using this method.

Topology Optimization Guides Efficient Material Distribution

Within a given design space, once boundary conditions and load cases are set, the topology optimization algorithm automatically computes the optimal distribution of material, removing "redundant" material in low-stress zones and reinforcing the critical paths of force flow. The results often present natural, organic forms, which coincide with the aesthetics of many architects. Using this technique, we design the layout of internal stiffeners for GRC double-curved panels, achieving "on-demand allocation" of material.

Analysis Results Guide Design and Detailing

The results of force flow analysis directly guide detailed design. High-stress zones require local thickening or additional stiffening ribs; low-stress zones can be appropriately thinned or hollowed out to achieve lightweighting. Joint details must be coordinated with the direction of force flow to avoid secondary stresses. Through analysis, we ensure that the entire system carries load clearly and transfers force directly, eliminating safety hazards at the source.

Force flow analysis of double-curved GRC places perceptual artistic forms on a rational scientific foundation. With its powerful computational analysis capabilities, Qinglong Group ensures that every curve is not only beautiful but also embodies rigorous structural logic.