pressures due to vacuum bag

[tomotomotomo]

Hi,
firstly, i've never used cosmos so please bear with me...
I'm looking to simulate a glass laminate being placed inside a vacuum bag, and being de-aired under vacuum.
so far i've modelled the glass laminate.
How would you guys go about modelling the bag and simulating a vaccum inside that bag on sworks/cosmos?
Is it actually possible, as a person on another forum suggested it isn't?
it's quite frustrating as I don't want to waste my time trying to do something if its not actually possible :s

Thanks
James

 

[ZillionM]

Can you post a pic of your 'glass laminate being'?

 

[vims]

To me it seems "impossible". The easiest way to do simulate teh bag is to apply the pressure directly on the model, but I guess the distribution of the pressure over the surface what you are interested in.

 

[Phreakish]

the vac bag is going to apply a known static pressure to the laminate, so a uniform pressure applied normal to all 'exposed' surfaces should do.

In reality, the bag will put other stresses/loads onto the part due to a 3d volume being inside of a bag that cannot truly conform to the object, will this effect be large enough to consider? Its possible if its a small laminate.

Is the part just laid into a bag? or is it fixtured to a table and a layer of plastic sheet sucked down on it? These all affect how you'll restrain it. If its just stuck in a bag and put under vac, it could be tricky, if fixtured to a table, and then force is applied against an underlying mandrel or mold, it could be easier.