Civil Engineering PE Civil Engineering Theory of Structure 3

Question 1

A truss is statically determinate if m + r = 2j, where m = members, r = reactions, j = joints. A truss has 9 members, 3 reactions, and 6 joints. It is:

Accepted Answer

Statically determinate

Answer

Statically indeterminate

Answer

A mechanism

Answer

Unstable

Question 2

In the slope-deflection method, the slope-deflection equation for a near-end moment M_AB is written in terms of:

Accepted Answer

θ_A, θ_B, chord rotation ψ, and fixed-end moments

Answer

Only the near-end rotation θ_A

Answer

Only the applied load and span length

Answer

Member stiffness and shear force only

Question 3

Virtual work principle states that for a deformable body in equilibrium, for any virtual displacement:

Accepted Answer

Virtual external work equals virtual internal strain energy

Answer

Virtual strain equals virtual stress

Answer

Displacement is proportional to load

Answer

Bending moment equals curvature times EI

Question 4

The plastic section modulus Z for a rectangular cross-section (width b, depth d) is:

Accepted Answer

bd²/4

Answer

bd²/6

Answer

bd²/3

Answer

bd³/12

Question 5

When analyzing a frame using the portal method for lateral loads, interior columns are assumed to carry:

Accepted Answer

Twice the shear of exterior columns

Answer

The same shear as exterior columns

Answer

Half the shear of exterior columns

Answer

Zero shear

Question 6

The conjugate beam method uses the M/EI diagram as the:

Accepted Answer

Load diagram of the conjugate beam

Answer

Shear diagram of the conjugate beam

Answer

Deflection curve of the real beam

Answer

Moment diagram of the conjugate beam

Question 7

A beam with EI = 20,000 kN·m² spans 8 m simply supported. A central point load of 100 kN produces a maximum deflection of approximately:

Accepted Answer

13.3 mm

Answer

26.7 mm

Answer

53.3 mm

Answer

6.7 mm