R. Jones et al., AUSTRALIAN DEVELOPMENTS IN THE ANALYSIS OF COMPOSITE STRUCTURES WITH MATERIAL AND GEOMETRIC NONLINEARITIES, Composite structures, 41(3-4), 1998, pp. 197-214
To achieve the potential cost savings resulting from the use of compos
ites in 'primary' structural components, i.e. wing fuselage skins, it
is important that composite structures be used outside the linear regi
me. However, before this can be achieved a computational methodology c
apable of analysing the detailed local stress states in conditions whe
re there are both geometrically and material nonlinearities is necessa
ry. This paper presents one such approach in which the 'global structu
re' is modelled by employing plate-type finite elements and the local
details are modelled with solid 3D finite elements. A coupling techniq
ues based on multi-point constraints is then employed to connect the 2
D and local 3D models. The approach presented allows for significant c
hanges in finite element mesh density and enables the connection of ve
ry detailed local models with less detailed global models. To illustra
te this analysis methodology a range of nonlinear structural problems
involving both geometrical and material nonlinearities are considered.
The methodology is first validated by considering a plate bending and
a post-buckling problem for which the solutions were known. The metho
dology is then used to analyse the post-buckling response of both a sh
ear and an axially loaded composite stringer/skin panel, In both cases
the computed results correlated very well with experimental results.
The results from these test cases suggest that the proposed analysis m
ethodology provides a viable computational tool for determining the lo
cal 3D stress states for structures undergoing complex nonlinear defor
mation states. (C) 1998 Published by Elsevier Science Ltd. All rights
reserved.