Analyzing the Bending Response of Aramid/Epoxy Beams and Rings

Publisher Website
Google Scholar
Abstract
Aramid/epoxy laminates often exhibit substantial material nonlinearity when subjected to bending. This is a consequence of the yield-like behavior of a Kevlar 49/epoxy lamina in fiber-directed compression. In this paper, analyses that utilize a simple idealization of compressive yielding are described and calculated results for Kevlar 49 reinforced beams and rings are compared with available data. Fabric reinforced beams are considered first. An existing analysis for unidirectionally reinforced beams is extended to accommodate the bilinear compressive behavior exhibited by a Kevlar 49 fabric reinforced lamina. Next, results of a finite element analysis of a thin, unidirectionally reinforced ring subjected to diametral compression are presented. This analysis uses beam elements that incorporate linear tensile and elastic-perfectly plastic compressive behavior. Finally, a method used to analyze quasi-isotropic beams tested in four-point bending and rings tested in diametral compression is discussed. This finite element analysis uses a layered shell element with a lamina constitutive model that permits elastic-perfectly plastic response to fiber-directed compression, but otherwise assumes linear elastic behavior. Comparison of calculated and experimental results corroborate the ability of analyses using a simple compressive yield model to account for much of the observed flexural nonlinearity in Kevlar 49/epoxy beams and rings.

This publication has 5 references indexed in Scilit: