Question

In a truss element, element temperature load is ___

(a) θ^e=EeAe

(b) θ^e=EeAeε0

(c) θ^e=EeAeε0\(\begin{Bmatrix}l \\ m \end{Bmatrix}\)

(d) θ^e=EeAeε0\(\begin{Bmatrix}-l \\  -m \\l\\m\end{Bmatrix}\)

This question was posed to me in final exam.

This interesting question is from Plane Trusses in chapter Trusses of Finite Element Method

Answer 1

Correct option is (d) θ^e=EeAeε0\(\begin{Bmatrix}-l \\  -m \\l\\m\end{Bmatrix}\)

To explain I would say: In a truss, temperature effect is arised then thermal stress problem is considered here. Since the element is simply a one dimensional element when viewed in local co-ordinate system, the element temperature load in the local co-ordinate system.