The Effect of Lay-Up, Core Material, and Cross-Sectional Geometry on the Structural Performance of Pultruded Fiberglass Utility Poles

Abstract

The structural performance of several pultruded fiberglass utility poles is investigated and compared with wood pole standards. The fiberglass poles are thin-walled tubes with an approximate hexagonal configuration. The outside of the poles have longitudinal grooves which create a dovetail configuration. The dovetails provide a convenient mechanism for attaching crossarms and other hardware to the tubular structure and contribute additional stiffness and strength at these attachment points. Manually operated clamping devices which can run up and down the grooves provide a safe environment for utility linemen. Structural evaluation includes a comparison of axial stiffness, flexural stiffness, maximum load, maximum bending moment, and load-deflection curves for several different pole cross-sectional geometries. Material elastic properties and fiber orientations are varied to determine the effect on structural performance. Several different fiber preforms, including unidirectional rovings and multidirectional fabrics, are evaluated. Results of the analyses are compared with the manufacturer's (Composite Power Corporation) preference in terms of manufacturabilit,. The effect of fiberglass sleeve inserts and solid foam cores is also investigated. Some of the analyses are compared with full scale test data and both the experimental and theoretical results are compared with utility standards for pole design. Failure mechanisms for different loading conditions and future analysis is discussed. Preliminary results show that the composite poles can achieve the standards required for the highest quality wood poles.