BCE Structural Analysis 4

Question 1

In matrix stiffness analysis, the element stiffness matrix for a truss member of length L, area A, and modulus E is of size:

Accepted Answer

4×4

Answer

A truss member has 2 DOFs per node (x and y translation) and 2 nodes, giving a 4×4 element stiffness matrix in 2D.

Question 2

The three-moment equation (Clapeyron's theorem) is used to analyze:

Accepted Answer

Continuous beams over multiple spans

Answer

Clapeyron's three-moment theorem relates the moments at three successive supports of a continuous beam, enabling indeterminate analysis span by span.

Question 3

A structure is geometrically unstable if:

Accepted Answer

All reactions are parallel or concurrent even if the reaction count is sufficient

Answer

Even with the correct number of reactions, a structure is geometrically unstable if all reaction lines of action are parallel or pass through a common point.

Question 4

In the stiffness method, the joint equilibrium equation is written as:

Accepted Answer

[K]{d} = {F}

Answer

The stiffness method forms [K]{d} = {F}, where [K] is the global stiffness matrix, {d} the displacement vector, and {F} the load vector.

Question 5

Which of the following correctly defines the flexibility coefficient f_ij?

Accepted Answer

Displacement at i due to a unit force applied at j

Answer

The flexibility coefficient f_ij is the displacement at coordinate i caused by a unit force applied at coordinate j, with all other loads absent.

BCE - Bachelor of Civil Engineering Practice Test

BCE - Bachelor of Civil Engineering Practice Test

BCE Structural Analysis 4