Question

In 3D truss element, the nodal displacement vector in global co-ordinates is  _____

(a) q^‘= [q1,q2]

(b) q^‘= [q1,q2,q3]

(c) q^‘= [q1,q2,q3,q4,q5,q6]

(d) Undefined

I had been asked this question during an online interview.

My query is from Three Dimensional Trusses in portion Trusses of Finite Element Method

Answer 1

Right choice is (c) q^‘= [q1,q2,q3,q4,q5,q6]

Easy explanation: Nodes will have nodal displacements or degrees of freedom which may include translations, rotations, and for special applications, higher order derivatives of displacements.