Tension and compression in axially loaded members

[influx]

The question tells us that a tensile force of 80kN acts upon the thin rod and hence we know there will be an equal but opposite force on the other side. However, I don't understand why there are compressive forces on the tube? We aren't told about this in the question.

Thanks

 

[SteamKing]

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The question tells us that a tensile force of 80kN acts upon the thin rod and hence we know there will be an equal but opposite force on the other side. However, I don't understand why there are compressive forces on the tube? We aren't told about this in the question.

Thanks

When you pull on the rod at point C, the tensile force is transmitted back to the plate and nut at point B. You cannot have a tension in the tube with this arrangement of parts.

Remember, the tube supplies a reaction to the rod so that it remains in equilibrium when the tensile force is applied.

You weren't told this in the question because it should be rather obvious.