Study on the mechanical response of anticlastic cold bending insulating glass and its coupling effect with uniform load

Abstract

Cold bending is a characteristic of significance for the beautiful curved glass curtain walls, because it affects them in terms of energy-efficiency and cost-efficiency. The increasing engineering projects call for more special studies on the mechanical properties of cold-bent glass panels, especially when the walls are built by insulating glass that is currently widely used while its relevant research is very scarce. This paper is devoted to studying the mechanical properties of anticlastic cold-bent insulating glass while taking different factors into consideration, including glass thickness, cold-bent torsion rate and cavity thickness. 9 pieces of insulating glass were manufactured for anticlastic cold-bending test and their coupled effect with identical load is also studied, and numerical finite element analysis sessions were carried out to simulate the experimental results for each one of them. Further, we analyzed the stress distribution performance of the sample pieces under cold bending and a uniform load, followed by discussions about stress transfer controls in glass plates. The results showed that the cold-bent control stress is on the surface with direct loads from cold bending and close to the cold-bent corner on the short edge, and it is transferred from the parts around the corner to the center when the uniform load plays a leading role in generating stress. This transfer could occur under a relatively small load with a small cold-bent torsion rate. A higher cold-bent torsion rate in cold bending contributed mostly to greater center stress in the glass, and as the glass thickness grows, stress and deflection at the plate center would significantly drop. However, the effect of cavity thickness on the anticlastic mechanical response of insulating glass was found to be trivial.

Experimental Study on Single Corner Cold Bending Mechanical Response of Laminated of PVB Interlayer Tempered Glass Panes and the Coupling Effect with Load

“…In mechanics, it is the most unfavorable stress condition of the glass panes of the curtain wall, which is called the reverse coupling effect. According to reference [19], the maximum wind pressure of the outer glass is grade 9, and the corresponding load is 5 kPa. The load test is conducted in five stages.…”

“…Sun Jian and Jin Zhiqiang [7,18] verified the reliability, fatigue performance and construction technology of a single cold-formed glass pane of a large bird-shaped lighting roof in Suzhou Central Plaza through experiments. Xide Zhang [19] conducted an experimental study on cold bending and coupling with a uniform load of hollow tempered glass panes.…”

An Experimental Study on Cold-Bending Stress and Its Reverse-Coupling Effect with the Uniform Load on Cold-Bent SGP Laminated Glass

“…All the glass panels were 2200 × 1200 mm in planar size, and were composed of 2 pieces of tempered glass with a thickness of 5 mm and an inserted SGP layer. Because there is no precise description of the index of anticlastic cold bending [20], to describe the degree of cold bending of the glass panels we referred to the warpage measurement of PCB board in the IPC-TM-650 test methods manual and define the cold-bending curvature as:…”

“…The uniform load tests are shown in Figure 3b. According to [20], the wind load is 5 kPa when the wind load resistance of the exterior window reaches the highest level. Based on this idea, the uniform load was divided into 5 levels (each at 1 kPa) and maintained for 15 min.…”

“…After the uniform load is applied, the cold-bending stress in the glass panels will be coupled with a kind of new stress generated by the load, which can be considered a stress problem of a thin plate with initial stress [19]. The interlayer within laminated glass deforms and interacts with the glass during cold bending, resulting in difficult theoretical analysis and complex prediction of the overall stress [20]. As a result, practical experiments are needed to reveal cold-bending stress and its coupling effect with the uniform load in cold-bent SGP laminated glass panels.…”