Prediction of Energy Absorption Capability of Composite Stiffeners

Abstract

An analytical methodology for predicting energy absorption capability of composite open-section stiffeners is oresenled. The methodoloev is based a n comnosite laminate and elastic stahilitv theories and on ... nundintensional crippling dalu. Applicalions of lhi\ mrlhudology lo gmphitelcpoxy rhan~nrl and ha1 stiffenrn are pre~enlcd. 'rhc ynphil~~l./~po~y \liffencr dr\igns tltal ,"err. qtudicd ulilircd ply drop-nlTs 11, inilidtc crushing andfa maintain ela;iestabil&. The analytical ;esults for the energy-absorbing capability of the stiffeners are compared with test results. The energy absorption characteristics associated with different laminate designs are identified, and their significance to the design of energy-absorbing stneners is discussed. Notation A;Element cross-sectional area (in2) and crippling of metallic stiffeners (Refs. 1-3). Consequently, . , b Element width (in.) there are-reliable design methods available that are routinely used . . Dij Laminate flexural stiffness (Ib-in.) for conventional metallic structural elements. With respect to E Stiffener average elastic modulus (IbIin.2) local buckling and crippling of composite stiffeners, several research efforts have been directed at generating experimental Ei Element elastic modulus (lblin.2) databases, and some design support testing has been conducted I Element thickness (in.) v, v, Laminate Poisson's ratios P Minimum radius of gyration of stiffener cross section (in.)