Slope-deflection method is suitable for
- ADeterminate trusses.
- BIndeterminate frames.Correct
- CRolling loads.
- DInfluence lines.
Solution
Concept
Applicability of slope-deflection method to frames
Formula
MAB = MFAB + (2EI/L)·(2θA + θB - 3Δ/L)
Step-by-step solution
1. Slope-deflection method formulates equations with joint displacements (slopes and deflections) as fundamental unknowns. 2. It solves for bending moments at joints of continuous beams and rigid indeterminate frames. 3. Pin-jointed trusses develop only axial forces without flexural slope-deflection behavior. 4. Hence, the method is specifically suitable for analyzing indeterminate frames. Answer: B
Explanation
The slope-deflection method is a classical displacement (stiffness) method developed for the analysis of statically indeterminate beams and rigid-jointed frames. It expresses member end moments in terms of joint rotations and translations.
Why the other options are wrong
A) Determinate trusses are analyzed by method of joints or sections, not slope-deflection. C) Rolling loads are primarily analyzed using influence line diagrams. D) Influence lines represent moving load response, not a structural displacement method.
Shortcut
Slope-deflection = Displacement method for indeterminate beams and rigid frames.
Common mistake
Selecting trusses, which have hinged joints without bending moments, making slope-deflection inapplicable.
Correct answer: B) Indeterminate frames.