What does a microscopic diatom have to do with an automotive
wheel? Give up? Workers at the German polar and oceanographic
research organisation, AWIBremerhaven (www.awi-bremerhaven.de)
have been investigating the functional morphology of naturally
occurring forms such as the intricate silica cell wall structure
of the tiny marine diatom, Arachnoidiscus japonicus. The intention
is to scale up this organism’s symmetrical, circular shape,
with its radial stringers and concentric supports, and use it as
the basis of a new automotive wheel that can be made from fibre
reinforced plastics (FRPs), rather that the heavier metal alloys
in use today.
Hitherto, FRPs have not been considered suitable
for this type of application because special geometries are needed
to cope with the dynamic forces imposed. However, the structure
of the diatom A. japonicus is optimised for radial strength and
it proved a good candidate for further investigation. The morphology
was analysed and drawn into a CAD program, and a finite element
analysis undertaken to analyse the loadings and optimise the structure. At present, the prototype FRP wheels
are undergoing roadworthiness tests.
While this might be one of
the more exotic examples of ‘reverse engineering’, there’s
a lot of off-the-shelf software out there to help you bridge the
gap between the physical and virtual worlds as you go about your
product development projects. The freeform sculptured surface forms
the basis of most product designs, from mobile ‘phones to some
of the latest car concepts. Reverse engineering can help capture
the 3D CAD image of a physical concept or a part that is destined
for the design and manufacturing process.
Delcam’s CopyCAD (www.delcam.com/copycad) is a useful set
of tools for freeform surface creation, supporting just about everything
from concept model to the production tooling. The software creates
high quality engineering surfaces over point cloud data, captured
from scans of the physical object, and its advanced triangulation
functions enable “watertight” STL file creation for
rapid prototyping and tooling. CopyCAD features a ‘3D paintbrush’ that
allows users to smooth and sculpt a triangle model interactively
in real time.
3DReshaper software from Technodigit (www.technodigit.com) can
be used for 3D reverse engineering or 3D surface reconstruction.
The 3D point clouds used in the modelling process can be derived
from any technique - 3D scanner, digitiser, CMM, laser triangulation
system, time-of-flight laser and so on - and you can enter literally
millions of points, without limit, to create meshed models in “seconds” according
to Technodigit. The software has some interesting features that
allow you to produce high quality 3D surface cloud files. Generated
models can be used directly for rapid prototyping, tool path generation
or finite element analysis.
Pro/Engineer users might be interested to learn that they are
now able to digitise directly in their CAD environment using reverse
engineering software from HighRES (www.reverse-it.com). The company
specialises in the development of tool sets that easily translate
raw digitised data fromportable coordinate measuring machines (CMMs),
as native CAD/CAM entities, thus avoiding those data translation
issues that can slow up your reverse engineering projects.
Revware’s
(www.revworks.com) software provides a link between your modelling
software and the 3D digitisers and portable CMMs you use to obtain
point cloud data. Its key product, RevWorks (now available for
SolidWorks users) allows you to collect data in real time from
these 3D measurement devices. It also features an ‘Alignment
Manager’, which allows you to create leap sets - very useful
when moving your digitiser between stations surrounding a large
object.
Finally, once you have your CAD model and want to visualise it
in a particular way, or wish to do a bit of post-processing following
an FEA analysis, there’s always Tecplot (http://tecplot.adeptscience.co.uk).
Tecplot’s
interface makes it easy to pan, zoom and rotate 3D objects, and
easily switch from one view of the data to another. Light-source
colour and shading options bring an extra dimension of realism
to presentations, while users can explore 3D volumetric data by
interactively slicing along X-, Y-, or Z- planes or arbitrary cutting
angles.
Dr Know's recommended download is Tecplot 10.4 Windows Demo - download yours today.