Axial deformation in composite beam

[gematt7]

I have to calculate the elongation of a pencil under a load.
I know I have to use deflection = PL/AE but since the pencil has 2 materials in it I have to modify that equation.

I know that both materials extend by the same amount.

Could anyone explain to me how to get that equation?

 

[PhanthomJay]

Yes, you have noted that the deformations of each material are the same, assuming no slippage between the component parts. A portion of the applied load is carried by each material. Set up equations for the deformation of each part.

 

[nvn]

gematt7: I agree with the post by PhanthomJay. Hint: P1 is the axial force on material 1; P2 is the axial force on material 2. Set up the equations for the deformation of each part. We are not allowed to set up the equations for you. It appears you deleted the required homework template.