dukefool

A structural member is fabricated from a solid round bar of steel with a diameter d=50mm. If the member is 6 ft long, determine the maximum axial force that can be applied if the axial stress is not to exceed 175 MPa and the total elongation is not to exceed 0.14% of its length.

This is what I got:

Axial stress = Axial Force/Area of the bar crosssection => Axial Force/pi*(0.025m)^2

Total Elongation = ((Final Length - Initial Length)/Initial Length)*100%

I'm not sure how to piece the two together to find the maximum axial force.

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My shot in this is to multiply the axial force to the original length of the rod then divide it by the area of the cross section of the original rod and the change in length of the rod which is the axial deformation length.