Impact performance of pultruded beams for highway safety applications

Abstract

The Federal Highway Administration (FHWA) is currently surveying composite materials for use as roadside safety structures. The primary application under consideration is a composite roadside safety rail (ie composite barrier system). A roadside rail system must have suitable characteristics to contain and redirect errant, out-of-control vehicles. While at the same time, the structure must be crashworthy or 'forgiving' to vehicle occupants. The objective of this study is to present the findings from an iterative design process to optimize the impact performance of pultuded beams. A series of impact and quasi-static tests on several glass fiber-reinforced composite beams having both open and closed cross sections have been conducted as a part of this process. These tests have built upon previous FHWA studies which have investigated the impact and static behavior of pultruded composites. The results obtained for maximum strength and energy absorbing characteristics from this study are being applied to the development of a full scale prototype guardrail. The beams tested were all standard pultruded single or multi-cell tube sections manufactured by Creative Pultrusions, Inc. Several of the beams also had two outer layers of Fabmat 0-9- glass woven roving applied by a hand lay-up procedure. Both polyester and vinylester beams were tested. The beams were simply supported and approximately one-third the size of a conventional roadside rail section. The impact testing was conducted at the FHWA Turner-Fairbank Highway Research Center in McLean, Virginia. Both impact and quasi-state tests were conducted under identical boundary end conditions.