This study documents numerical modelling of different types
of polygon structures. To reduce computation costs, planar and extruded
Ti6Al4V(ELI) hexagonal shell structures were used to predict stresses in the
out-of-plane and in-plane directions. Numerical modeling is especially useful
for complex behavior analysis of structures. It is employed to forecast a
structure's mechanical characteristics. Conversely, analytical modeling is
based on mathematical equations that may not accurately reflect the geometry of
the model, which limits its ability to anticipate behavior, especially that of
structures. In such cases, numerical
modelling is used for predicting structural bending, axial deformation, and
buckling behaviour. In the present work,
the hexagonal polygon was subjected to out-of-plane and in-plane uniaxial
compression loads. This was done to compare the bending and buckling behaviour
of finite element (FE) models to analytical models. The numerical and
analytical results were then compared to determine how the ratio (t/L) of the
wall thickness (t) and length of the polygon members (L) influenced the
effective stiffness of the hexagonal polygon. Emphasis was placed on the
analysis of buckling failure in the present work as it was shown here that for
direct compression loading along the z-axis, lattice wall structures were more
likely to fail under buckling than in direct deformation. Non-linear numerical
analysis of buckling was adopted for use in the present work instead of linear
numerical analysis in recognition of the fact that the latter method only
identifies buckling modes, while the former also avails information about
deformation. This then allows the investigation of possible failure of thin
structures in buckling. The simulation for nonlinear analysis of buckling was
run using the Johnson-Cook Model that is built into ABAQUS/CAE. The triangular
polygon was seen to have the greatest load-bearing capacity and stiffness of
all polygons that were modelled. The hexagonal model was observed to generate
deformations due to compression, similar to those reported in the literature.
The critical buckling loads for the analytical honeycomb (HC) models were found
to be below the yield stress for (1-, 1.125-, and 1.25-mm wall thicknesses) and
above the yield stress for all FE HC models, respectively. The effective
stiffness of the HC models was observed to increase with the increasing (t/L)
ratio, for both the numerical and analytical models. Future research should
focus on experimentation for all of the different polygon structures
computationally modelled in this work in order to confirm the obtained results.
Author(s) Details
M. I. Chibinyani
Department of Mechanical and Mechatronics Engineering,
Central University of Technology, Free State, South Africa.
T. C. Dzogbewu
Department of Mechanical and Mechatronics Engineering,
Central University of Technology, Free State, South Africa.
M. Maringa
Department of Mechanical and Mechatronics Engineering,
Central University of Technology, Free State, South Africa.
A. M. Muiruri
Department of Mechanical and Mechatronics Engineering,
Central University of Technology, Free State, South Africa and Department of
Mechanical and Manufacturing Engineering, Southern Eastern University of Kenya,
Kitui, Kenya.
Please see the book here:- https://doi.org/10.9734/bpi/cmsdi/v4/8584E
