COMPARISON OF CHARACTERISTIC VALUES FROM MULTIPLE PRODUCTION RUNS OF A PULTRUDED COMPOSITE PRODUCT

摘要

The determination of characteristic values for the mechanical properties of pultruded composite products used in designs is a critical aspect of the load resistance factor design (LRFD) standard being developed for pultruded composites. The load resistance factor design standard is currently under development by the American Society of Civil Engineers (ASCE) through a project initiated by the Pultrusion Industry Council of the American Composite Manufacturers Association (ACMA). Instead of the traditional allowable stress design (ASD) methodology, LRFD is a reliability-based design methodology that takes the known variability of applied loads and materials into account. In order to quantify the variability inherent for a given material, the characteristic value, a statistically-based value of a material property of interest must be determined. This study investigates the repeatability of the characteristic values of mechanical properties when determined from two separate production runs of a commercial pultruded composite product. In this study, commercial pultruded sheets were examined, and characteristic values of longitudinal tensile strength properties for each production run were determined using ASTM D7290, as specified in the LRFD Pre-standard. Results from the study will help the pultrusion community understand the mechanical testing needs when characteristic values to be published for a particular product are established.