Experimental and Numerical Investigation of Crash Behavior of Composite Helicopter Cruciform Elements

This paper describes an experimental and numerical investigation on the energy absorbing capabilities of composite intersection elements for helicopter subfloor. The crash tests were performed using a drop test machine and a finite element model was developed using LS-DYNA. To calibrate the numerical model, coupon testing and tube crushing experiments were performed. The obtained results showed that the composite subfloor components possessed a good capacity of energy absorption. The simulation accurately predicted the average load and the specific absorbed energy, as well as the failure mode, but exhibited an initial peak load more marked than the one obtained in the crash tests. Thus, this investigation can help to build confidence in the future use of non-linear dynamic finite element codes for the design of composite primary structures subjected to crash loading.