Ansys and Composite Material (Density/Ply

[rociogp]

Hi all

My name is Rocío and I need some
help with composite material and Ansys program. I have done a model of part of
a bus' structure using shell 99 and I have a problem. I need to know the weight
of the models but I'm not sure where I must to introduce the density properties.
I have the density of the skin according to the volume fibre/matrix. If I
introduce it’s in the material proprieties, and apply to each ply, the model is
very heavy and if I introduce it in the real constant (in ADMUSA, dividing the
total density by the total ply numbers???) the model is very light. Where can I introduce the density material and
how?

Thank for all.

 

[cbrn]

Hi,
I suspect you're having some problem with the dimensionality of the "density" measure unit. You have to be very careful to be consistent with your units system: for example, it is not so obvious that, if force is in [N], length is in [mm] and time is in , then the mass unit is in [ton], not [kg], and so the density is in [ton/mm^3].
I don't know if you built your FE model by direct input of nodes and elements, or if you have meshed surfaces. In the second case, you can set the "area properties" of all your areas to have a certain density. Then, do *ASUM and then list your areas' properties: it will give you the "mass" of each, based on a unit-length thickness.

Regards