An Analytical Method For Predicting Energy Absorption Capability Of Composite Stiffeners

An analytical methodology for predicting energy absorption capability of composite stiffeners is presented. The methodology is based on composite laminate and elastic stability theories and on nondimensional crippling data. Applications of this methodology to channel and hat stiffeners commonly used in rotorcraft structures are presented. The siffener designs studied utilize ply drop — offs to initiate crushing and to maintain elastic stability. The analytical results 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 stiffeners is discussed.