Optimal Static Performance Analysis of Large-Span Space Aluminum String-Beam Structures

Aluminum alloys offer advantages such as lightweight properties, high strength, and excellent corrosion resistance. To expand their application in long-span spatial structures, prestressed cables have been introduced into aluminum alloy structural systems, forming a new type of string-beam structure. To further investigate the static performance of aluminum alloy string-beam structures, a static analysis was conducted based on the greenhouse project for the archaeological site of the Qin Eastern Mausoleum. This analysis examined the structural response under various load combinations, as well as the effects of the number of struts, cross-sectional area of the cables, prestress level in the cables, and the sag-to-span ratio of the cables. The results indicate that the incorporation of prestressed cables significantly enhances the static performance of aluminum alloy string-beam structures. Under the most critical load combination, the maximum stress observed was 189.45 MPa, and the maximum vertical displacement was 137.31 mm, both of which comply with design specifications. The structure was found to be most sensitive to temperature load. From the perspectives of structural performance and construction economy, setting the number of struts between five and seven is optimal. Increasing the cross-sectional area of the cables effectively reduces structural deflection but leads to an increase in internal stress. Similarly, increasing the prestress level effectively reduces structural displacement. The sag-to-span ratio of the cables has the most pronounced effect on structural stiffness: when the ratio increases from 0.025 to 0.065, the mid-span displacement increases by 33.51%. These findings demonstrate that aluminum alloy beam-string structures are suitable for long-span spatial structures.