Indiana University-Purdue University Indianapolis (IUPUI) / The use of carbon-fiber reinforced composite materials is not novel in the field
of motorsports industry. Their use in collapsible structures for crashworthiness is
however not fully understood and predicted. Due to the complex failure mechanisms
occurring within the material, the energy absorbing capacity cannot be easily pre
dicted. The need to understand their contributions in crashworthy structures is thus
of great importance. Furthermore, failure of carbon-fiber composites is highly depen
dent on the geometry of structure. Problems arise in both experimental and numerical
modelling of these structures. Although many explicit FEA codes exist, they often
include experimental parameters that need to be calibrated through either coupon
tests or actual crash tests. As composite structures become more commonly used in
automotive industry, it is necessary to set some guidelines to successfully model and
simulate composite crashworthy structures.
The numerical modelling was done in LS-DYNA Enhanced composite damage
MAT54. The material properties were configured using experimental coupon tests.
The tests were conducted on square composite tubes. The Specific Energy Absorption
(SEA) of the tubes were calculated through several coupons. As SEA is a function of
geometry, it was necessary to conduct tests with similar geometry as seen in nosecone.
MAT54 was chosen to simulate both crush and crash simulations due to its capability
to simulate element level crushing. Furthermore, various modifications within the
material model, improve its accuracy to determine composite failure.
The research utilizes the characterization of material inputs in MAT54 by con
ducting quasi-static compression tests on simpler but similar geometry. By utilizing
inputs, a zonal optimization was conducted on the nosecone geometry. The number of
layers, layer orientations and ply thicknesses were varied to vary the energy absorbed
per zone. The deceleration of the vehicle can thus be controlled, and the weight of
the structure could be reduced.
| Identifer | oai:union.ndltd.org:IUPUI/oai:scholarworks.iupui.edu:1805/19976 |
| Date | 08 1900 |
| Creators | Deshpande, Archit M. |
| Contributors | Dalir, Hamid, Agarwal, Mangilal, Tovar, Andres |
| Source Sets | Indiana University-Purdue University Indianapolis |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
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