Fiberglass composite study in SolidWorks, Help !

[firasf1dream]

Yeah its incredibly tough to get information on it and in all honesty the fea programs for composites are in their infancy. Many companies have their own proprietary data that they will not share.

it looks like you are gong to have to use a linear isotropic solver...which will probably satisfy the academic requirement. But in practice it would not be sufficient. As long as this steering wheel isnt on a moving vehicle you probably have no major safety concerns. That would still be up to you to analyze.

I looked at a few data sheets and it appears your CSM composite will probably be closer to 100 MPa yield strength. thats wayyyy lower than what you have, but still within the margin of your analysis. I dont remember the modulus. The values you are using now are at least 20x greater than what you can really expect from the composite.

As you gain more experience...you will realize there arent many how-to articles on what youre doing...so application of theories becomes paramount.

yes no moving vehicle, the moving vehicle is 1/4 scale it will not have any human factor which means my concerns are less, the only thing that concerns me is to make the floor able to handle the wait of the engine and other components, a good thing is that i will be using aluminium for some parts which give some weight advantage,

about the 100Mpa ! wow ! where did u get it, i mean the datasheet ?! because in all the sources i search on people were saying values from 2000Mpa to 2800 Mpa !!

[sgth0mas]

Yeah its incredibly tough to get information on it and in all honesty the fea programs for composites are in their infancy. Many companies have their own proprietary data that they will not share.

it looks like you are gong to have to use a linear isotropic solver...which will probably satisfy the academic requirement. But in practice it would not be sufficient. As long as this steering wheel isnt on a moving vehicle you probably have no major safety concerns. That would still be up to you to analyze.

I looked at a few data sheets and it appears your CSM composite will probably be closer to 100 MPa yield strength. thats wayyyy lower than what you have, but still within the margin of your analysis. I dont remember the modulus. The values you are using now are at least 20x greater than what you can really expect from the composite.

As you gain more experience...you will realize there arent many how-to articles on what youre doing...so application of theories becomes paramount.

yes no moving vehicle, the moving vehicle is 1/4 scale it will not have any human factor which means my concerns are less, the only thing that concerns me is to make the floor able to handle the wait of the engine and other components, a good thing is that i will be using aluminium for some parts which give some weight advantage,

about the 100Mpa ! wow ! where did u get it, i mean the datasheet ?! because in all the sources i search on people were saying values from 2000Mpa to 2800 Mpa !!

The material properties you read were for the continuous fibers in direct tension. CSM is small discontinuous fibers held together by resin. While your fiber may have a 2000+ MPa tensile strength, your resin only has a 65 MPa tensile strength. With CSM you rely more on the resin than the fibers for strength in many directions.

The data I found was located in the "Concise Encyclopedia of Composite Materials" p. 117. ISBN 0080912656.

It may be higher or lower but its impossible to know without actually testing a sample.

[sgth0mas]

If you were using Ud, a continuous weave or wound filament you would be much closer to fiber strength.

a composite is exceptionally close to fiber strength if its a Ud in the direction of the fiber orientation with a very high fiber content. But it will be very weak in transverse loading.

[firasf1dream]

aha but it's weird because the CSM that i saw is like this like a 1 piece renfort like this https://vikingplastics.ca/wp-content/up ... c3f3aa.jpg
the put it like this layer by layer so you comment please ?

btw if a composite is linear isotropic then what is exactly made from ?! is it layers of Ud fibers or what exactly ?

[sgth0mas]

aha but it's weird because the CSM that i saw is like this like a 1 piece renfort like this https://vikingplastics.ca/wp-content/up ... c3f3aa.jpg
the put it like this layer by layer so you comment please ?

btw if a composite is linear isotropic then what is exactly made from ?! is it layers of Ud fibers or what exactly ?

Yes its a big sheet of CSM, but its made of small lengths of chopped fiber held together losely by a small amount of resin or other binder. Each individual fiber is much shorter than the overall length.

You also have to look at volume fraction. If you have 30% csm and 70% resin, then only 30% of the cross section will even have fibers capable of bearing high tensile loads. The remaining 70% is your 65 MPa resin. And those 30% of fibers will rarely be oriented in the actual loading direction.

No composite that im aware of is truly linear isotropic. Many of us were simply telling you to solve it that way with conservative material properties because you dont have the full material specs, the FEA package, or experience solving nonlinear anisotropic problems for composites (very very few people do actually).

Its been mentioned a few times that CSM can be treated isotropically with in plane loading, but not when loaded in other directions.

[firasf1dream]

ah ok in plane u mean the traction but not shear ?

the problem is the properties ! can't find, do you pdf that i can get the properties from ? i tried few none of them is useful not even the composite handbook

[sgth0mas]

If you google the book isbn i postwd and looked at page 117 in the book preview, you will see the table.

Use US websites if you can

[sgth0mas]

In plans means if youre looking down at the csm while its laying flat on a surface, it only sees loads in the xy plane. Almost as if you had a sheet of paper held directly in front of you and you pulled outwards longways Or heightways.

[firasf1dream]

yes i understand, about the google i tried to google that book i search for hour no way of finding a copy of it to download

[PlatinumZealot]

Since you are using a relatively cheap material (fibreglass) I say just do it the old school way make the thing and test it on a bench. OR even more fun mount it on a hub that is not connected to anything and grip the wheel with both hands, (or jump on it with both feet) and try smashing it as hard as you can. This should simulate the g-forces in a crash. The wheel should be strong enough not break with the impact forces of your upper body weight (or entire body weight if you want). If the material is not strong enough it will crack... this means go back and add in more layers. If it does not crack... this means you can make a new one and use one less layer. etc etc..

[firasf1dream]

Since you are using a relatively cheap material (fibreglass) I say just do it the old school way make the thing and test it on a bench. OR even more fun mount it on a hub that is not connected to anything and grip the wheel with both hands, (or jump on it with both feet) and try smashing it as hard as you can. This should simulate the g-forces in a crash. The wheel should be strong enough not break with the impact forces of your upper body weight (or entire body weight if you want). If the material is not strong enough it will crack... this means go back and add in more layers. If it does not crack... this means you can make a new one and use one less layer. etc etc..

i appreciate your reply but no that doesn't work that way because i need to make a study and simulation of it

[firasf1dream]

Guys,
i would like to know something please in a very simple way:
Solidworks asks for properties of E-Glass Fiber, so these properties should be just for the fiber without resin,
so the simulation is made for the fibers alone, ok so how to do the simulation for the alloy of the resin and the fiber ?
should i just enter the properties for both by applying calculation using the alloy method Ef + Em ?

[sgth0mas]

Does solidworks ask if its chopped or continuous?

[firasf1dream]

Does solidworks ask if its chopped or continuous?

no it doesn't say anything, just E-Glass with the density already in the library of solidworks, and i must enter all the other properties

here is a picture of the properties asked, i must define up top the type: Linear isotropic, non linear etc ...

[Cold Fussion]

I would think that you're going to have to define you're own custom material and the material properties you enter will be of the resin + fibre composite. In introductory material science classes a composite material is often defined a linear mix of both elements, which varies based on the load direction relative to the fibre direction, however this is probably too simplistic for your analysis. Material science was never a strong point for me so I can't help you beyond that.