A curved beam element and its application to traffic poles

Abstract

Curved traffic poles may vibrate noticeably when excited by the wind. The finite element method can be utilized to analyze these beam-like structures. A three-node, curved beam element has been developed for the s atic and dynamic analysis of curved poles. Shear deformation as well as rotary inertia effects are included. Furthermore, reduced integration is used to prevent the shear locking problem. Several examples are used to verify the accuracy and computational efficiency of this element. The results agree well with exact solutions or results taken from the literature. The element is used to analyze the wind induced vibrations of curved traffic poles. Natural frequencies and the corresponding mode shapes are computed. Time integration is utilized to compute the dynamic response of curved poles having hexagonal and octagonal cross-sections. The initiation of galloping is investigated and critical wind speeds are found.