Modelling and Meshing Aluminium Honeycomb in CAD

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Modelling and Meshing Aluminium Honeycomb in CAD

Author	Message
NigelGroom	NigelGroom posted 10 Years Ago HOT Topic Details
Group: Forum Members Posts: 10, Visits: 43	I have designed an impact attenuator for a formula student car in Solidworks but I am having trouble meshing and analysing the assembly due to the high number of elements and the complicated structure of the honeycomb. I have attempted this with the solid accurate model, and with a model made from shell elements (where the foil thickness is taken into account for calculations but not modelled). Even on the best computers at my university the analysis fails in both solidworks and in Autodesk mechanical Algor, due to Jacobian errors, which I believe is due to too many elements. Does anybody have any experience modelling and testing honeycomb like this? The honeycomb used is the 19.1mm from easy composites. Another idea I have had is to forget the honeycomb pattern, and create the assembly from solid blocks with the properties of the aluminium honeycomb, however this requires me to input value for the youngs modulus and poissons ratio etc which I am having difficulty obtaining. Any advice or feedback on this issue would be greatly appreciated. I can attatch an image of the attenuator so it is easier to understand. Many thanks Nigel Groom Attachments Atten3TITLE.PNG (1.2K views, 67.00 KB) atten2.png (2.8K views, 344.00 KB) Tags aluminium honeycomb autodesk honeycomb impact attenuator solidworks
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Warren (Staff)	Warren (Staff) posted 10 Years Ago HOT Post Details
Group: Administrators Posts: 2.5K, Visits: 8.5K	You may well struggle to model individual cell behaviour on that scale. A solid material may well be a better modelling approach as long as you accept the constraints and limitations that will impose on your results. You could of course model only a few cells as a comparative test then use the data to compare to the solid model to see if it is representative. The mechanical data we hold on the honeycomb can be downloaded here: http://www.easycomposites.co.uk/downloads/TDS/EC-TDS-Aluminium-Honeycomb.pdf Warren Penalver Easy Composites / Carbon Mods - Technical Support Assistant
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redeye	redeye posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 52, Visits: 559	I'm a little rusty on this as most materials I use are solid, but I am quite sure you could model a small part out of honeycomb and then apply loads and contraints, check the deflections in the loads axis and the deflection transverse to the loads axis and thereby calculate poisons ratio of the honeycomb. You could also calculate E/Youngs modulus. Then model the final part as a large solid and apply those properties. Shooting a bit from the hip here, busy as heck, but worth a try and I hope it helps.
	Reply Like 8
NigelGroom	NigelGroom posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 10, Visits: 43	Yes I think I probably will have to do that, thank you both for your advice. I am also working on a back up attenuator currently made from Polystyrene, similar to some of the off-the-shelf attenuators.
	Reply Like 10
NigelGroom	NigelGroom posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 10, Visits: 43	The difficulty there is selecting the correct material when conducting the analysis, the specific aluminium of the sheet, which I am unable to find. I know it is of the 3003 variation from the data sheet but that is all.
	Reply Like 8
redeye	redeye posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 52, Visits: 559	Oh, that would be an issue. Where's the honeycomb from? Looks like you need the suppliers input here or to do some lab testing.
	Reply Like 9
NigelGroom	NigelGroom posted 10 Years Ago HOT Post Details
Group: Forum Members Posts: 10, Visits: 43	It's the 19.1mm Aluminium Honeycomb from easycomposites https://www.easycomposites.co.uk/19mm-aluminium-honeycomb It says Alloy 3003, in Algor there are 4 different Aluminium 3003 materials but all have the same E and Poissons ratio so this may not actually be an issue.
	Reply Like 9