Simulating the Response of a Composite Honeycomb Energy Absorber, Part 1: Dynamic Crushing of Components and Multi-Terrain Impacts

Abstract

This paper describes the experimental and analytical evaluation of an externally deployable composite honeycomb structure that is designed to attenuate impact energy during helicopter crashes. The concept, designated the Deployable Energy Absorber (DEA), utilizes an expandable Kevlar ® honeycomb to dissipate kinetic energy through crushing. The DEA incorporates a unique flexible hinge design that allows the honeycomb to be packaged and stowed until needed for deployment. Experimental evaluation of the DEA included dynamic crush tests of multi-cell components and vertical drop tests of a composite fuselage section, retrofitted with DEA blocks, onto multi-terrain. Finite element models of the test articles were developed and simulations were performed using the transient dynamic code, LS-DYNA ® . In each simulation, the DEA was represented using shell elements assigned two different material properties: Mat 24, an isotropic piecewise linear plasticity model, and Mat 58, a continuum damage mechanics model used to represent laminated composite fabrics. DEA model development and test-analysis comparisons are presented.

Advances in Rotorcraft Crashworthiness: Trends Leading to Improved Survivability 37th Alexander A. Nikolsky Honorary Lecture

“…In March 2010, a full-scale crash test of a MD-500 helicopter was performed at NASA Langley's LandIR facility. The purpose of the test was twofold: to evaluate the performance of an external Deployable Energy Absorber (DEA) [50][51][52][53][54][55][56][57][58][59][60] and to assess the ability of LS-DYNA to predict the impact responses of the DEA, the airframe, and the seated ATDs, based on an integrated finite element model. This simulation was one of the first system integrated models developed and executed at NASA.…”

Numerička analiza dinamičkog ponašanja kompozitnog saćastog panela ispunjenog cevčicama pod dejstvom udarnog opterećenja male brzine u ravni panela

“…However, impact scenarios affecting these structures range from low velocity impacts (tool drop, hail on ground) over intermediate velocity impacts (runway debris, tire fragments) to high velocity impacts (bird strike, hail in flight, engine parts). Hence, extensive research was conducted on the honeycomb sandwich structure for studying their mechanical behaviour under quasi-static as well as dynamic loading [10][11][12][13][14][15][16][17][18].…”