Recent aircraft as well as rotorcraft design technologies include more and
mon composite materials. Their high mechanical characteristics and high mas
s specific energy absorption capability motivate their use in large primary
structures as well as in sub-floor structural and crashworthy components i
n preference to metals. Due to the increased performance of computers and n
ew explicit finite element (FE) software developments industry now consider
s using crash simulation technologies to study the crashworthiness of new a
ircraft design. In order to address the crash analysis of composite structu
res, which is much more difficult than the behaviour of ductile metallic st
ructures, a German/French research co-operation was set up between ONERA an
d DLR. This paper summarises results from the first 3 years collaboration a
nd some work performed within a European research project on composite fuse
lage structures. In the first part of the paper, ONERA presents its contrib
ution to the characterisation of composite materials from 10(-5) s(-1) up t
o 100 s(-1) on hydraulic machines. Simulations have been undertaken to mode
l the tests and evaluate the FE codes. In the second part DLR studies are p
resented on the application of a commercial explicit FE code to simulate th
e behaviour of generic energy absorbing composite sub-floor elements, repre
sentative for helicopters and general aviation aircraft, under low velocity
crash conditions (up to 15 m/s). This includes some comparisons between pr
edicted structural response and failure modes with observed test results. (
C) 2000 Editions scientifiques et medicales Elsevier SAS.