Structural Analysis Flashcards
7 cards from real BCE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Structural Analysis flashcards as text
In plastic analysis, the collapse load of a fixed-fixed beam of span L carrying a central point load P is:
Answer: 8M_p/L
Three plastic hinges form (two at fixed ends, one at midspan); virtual work gives P_collapse = 8M_p/L.
The conjugate beam method converts the real M/EI diagram into an equivalent:
Answer: Load on a fictitious beam, with slopes and deflections found as shears and moments
In the conjugate beam method, the M/EI diagram becomes the load on a fictitious beam; the resulting shear and moment equal the real slope and deflection.
Which loading condition produces the maximum positive bending moment at a section due to a moving distributed load?
Answer: Load placed only on the portions of the span where the influence line ordinate is positive
To maximize a response, load all regions where the influence line is positive for positive response and negative regions for minimum (negative) response.
Betti's reciprocal theorem states that for a linearly elastic structure:
Answer: Deflection at A due to load at B equals deflection at B due to load at A (for identical loads)
Betti's theorem states that the work done by system 1 forces through system 2 displacements equals the work done by system 2 forces through system 1 displacements.
In a portal frame analysis by the cantilever method (approximate), the assumption made about column axial forces is:
Answer: Column axial forces are proportional to their distances from the centroid of the column group
The cantilever method assumes the frame behaves like a vertical cantilever, so column axial forces are proportional to distance from the centroid of the column cross-sectional area group.
The stiffness of a prismatic beam member (far end pinned) used in the moment distribution method is:
Answer: 3EI/L
When the far end is pinned (free to rotate), the effective stiffness reduces to 3EI/L, and the carry-over factor becomes zero.
An arch is said to be 'efficient' when subjected to its funicular load because:
Answer: No bending moments develop — only axial compression
Under its funicular (pressure-line matching) load, an arch carries load purely in compression with zero bending moment throughout, making full use of material strength.