DISCUSSION THREAD
Hints:
Use the four-step plan:
1. Equilibrium - FBD of BCD and writing down the equilibrium equations.
2. Load/deflection/thermal - Write down the load/deflection equation for each of the two elements: e = FL/EA + αΔTL.
3. Compatibility - Use geometry to relate the member elongations to the displacements of B and D. Focus on using the correct signs in these equations.
4. Solve - Count the number of equations and the number of unknowns. If you have sufficient equations, solve for the axial forces in the members, and from those calculate the stresses. If not, go back to Steps 1-3 to see what you are missing.
Any questions? Ask (and answer) questions here.
We are asked to leave our answers in terms of alpha, deltaT, A, and b, but not in terms of the applied force P; just want to make sure that this is not a typo.
Yes, typo. I will fix the statement. Thanks for pointing out this.