Dynamic Characteristic Analysis of an Arch-String Structure

A finite element model of a single arch-string structure was established, and the dynamic characteristics of the structure were investigated using ANSYS. Taking an arch-string structure with a span of 30m and a rise-to-span ratio of 1/2 as the research object, the effects of several key parameters, including the rise-to-span ratio, cable prestress level, arch cross-sectional area, and cable arrangement, on the natural frequencies and mode shapes of the structure were systematically analyzed under self-weight only. In addition, a comparative analysis between the arch-string structure and a conventional pure arch structure was conducted under the same span, loading, and support conditions in order to clarify the dynamic advantages of the arch-string structural system. The results indicate that, within the parameter range considered in this study, the cable arrangement, cable prestress level, and arch cross-sectional area have relatively limited influence on the dynamic characteristics of the structure, whereas the geometric parameters of the outer arch, especially the rise-to-span ratio, have a much more significant effect on the natural frequencies. As the rise-to-span ratio decreases, the overall dynamic stiffness of the structure increases, leading to a notable increase in the natural frequencies. The results of this study can provide a useful reference for the dynamic performance evaluation and optimal design of arch-string structures.