Civil Engineering PE Civil Engineering Theory of Structure 5

Question 1

For a cable carrying a uniformly distributed horizontal load w over span L with a central sag d, the horizontal tension H at the supports is:

Accepted Answer

wL²/8d

Answer

wL²/4d

Answer

wL/2d

Answer

wL²/2d

Question 2

The upper bound (kinematic) theorem of plasticity states that a load computed by:

Accepted Answer

Assuming a valid mechanism is an upper bound on collapse load

Answer

Satisfying equilibrium only is a lower bound on collapse load

Answer

Satisfying both equilibrium and yield is the true collapse load

Answer

Maximizing internal work is the true collapse load

Question 3

For a beam-column subjected to combined axial load P and moment M, the interaction equation used in design checks the condition that:

Accepted Answer

P/P_n + M/M_n ≤ 1.0

Answer

P/P_n − M/M_n ≤ 1.0

Answer

P·M ≤ P_n·M_n

Answer

P + M ≤ 1.0

Question 4

The theorem of three moments assumes that the slope of the elastic curve is continuous at:

Accepted Answer

Each intermediate support

Answer

Midspan of each bay

Answer

The points of inflection

Answer

The free ends of the beam

Question 5

Which of the following correctly describes the stiffness of a member with a pin at the far end versus a fixed far end?

Accepted Answer

Far-end pinned stiffness = (3/4) × far-end fixed stiffness

Answer

Far-end pinned stiffness = (4/3) × far-end fixed stiffness

Answer

Both have the same stiffness

Answer

Far-end pinned stiffness = (1/2) × far-end fixed stiffness

Question 6

A propped cantilever of span L with UDL w has its prop removed. The released structure is a cantilever. Using compatibility, the prop reaction R is found to satisfy:

Accepted Answer

Deflection at prop due to R plus deflection at prop due to w equals zero

Answer

Deflection at prop due to R equals deflection at prop due to w alone

Answer

Slope at fixed end equals zero

Answer

Moment at free end equals zero

Question 7

In a space truss, the condition for static determinacy is:

Accepted Answer

m + r = 3j

Answer

m + r = 2j

Answer

m + r = 6j

Answer

m = 2j − 3