Optimum Design Of Large-span Steel Arch Truss Based On APDL Language

The structure of large-span steel arch truss has a good mechanical performance, but also has a series of advantages, such as lightweight, simple, beautiful, etc. In recent years, steel arch truss structure has been widely used in various engineering fields. But, the amount of steel for steel arch truss structure is large. So, optimum design and study of steel arch truss structure has the vital significance. The study makes the structure to satisfy the requirement of standard and the specific conditions to minimize the material and reduce the cost.According to characteristics of steel arch truss structure, The optimization mathematical model that bar cross-sectional area as discrete design variables, truss height as continuous design variables, the total mass as the objective function, at the same time, considering the strength, stiffness, stability and section size constraints is established. The SUBP and the SWEEP method are provided by ANSYS to optimize the design of discrete variables of large-span steel arch truss. Use APDL language of triangular cross-section arch truss is parametric modeling, and design geometry parameter input dialog box, saving modeling time. By optimization results of different spans, different rise-span ratios of triangular cross-section arch truss, the range of economic rise-span ratio and rise-span ratio are given. Finally, the optimization of the structure before and after modeling is conduced seismic analysis of the structure, and analyze whether to meet the requirements of seismic code.The optimization results show that total steel consumption reduces from the original 184.99 t to 153.27 t, saving 15.82% of the steel and the optimization effect is obvious. The ?of ratiospan rise triangular cross-section arch truss is in the range of 1/10 to 1/4. The economic ?of ratiospan rise triangular cross-section arch truss is in the range of 1/9 to 1/8 or so.