Composite Tube bending properties
Composite Tube bending properties
(OP)
I want to find the Young's Modulus of a composite tube (Concentric) made out of three tubes of different material glued together. Once the pipe is manufactured it will bend perpendicular to the axis. Can someone tell me where I can find the relevent equations.
Also I want to to find the poisson ratio for the composite tube. Is there an equation for this?
Thanks in advance.
Also I want to to find the poisson ratio for the composite tube. Is there an equation for this?
Thanks in advance.





RE: Composite Tube bending properties
If so The trick is that M/I=s/y=E/R, or more usefully s/(yE)=1/R
R is the same for all three tubes, the strain (s/E) is the same for each at a given y.
Now you know that you can easily derive an expression for the total EI of the assembly.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Composite Tube bending properties
Are the three different materials fibre reinforced composite? Are the fibres directions different for the three tubes? In order to be of any help I think some more info would be necessary.
RE: Composite Tube bending properties
If I'm correct, and if I recall correctly the theory of reinf.concrete, you should do this:
-call E1 the elastic modulus of one of the three materials
-for the remaining two materials define n2=E2/E1 and n3=E3/E1
-now Ic=I1+n2I2+n3I3 and
σ1=My/Ic
σ2=n2My/Ic
σ3=n3My/Ic
Concerning the Poisson's ratio, I don't know how to combine them, and I suspect this would depend on the type of induced stress (if you are dealing with simple bending, what ere you doing with Poisson?). Anyway I would average the ratii on the area of the cross sections of the tubes.
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RE: Composite Tube bending properties
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?