Govt Exams
For continuous beams with equal spans and uniform loading, the middle span typically experiences larger negative moments at supports and larger positive moments due to symmetry considerations.
Fixed-end moment for a fixed-fixed beam with central point load = ±WL/8. This is a standard formula used in slope-deflection equations.
DKI = 3n - r, where n = number of joints = 8, r = reaction components = 9 (3 fixed supports × 3). DKI = 3(8) - 9 = 24 - 9 = 15.
For a simply supported beam with UDL, maximum deflection occurs at 0.577L from either support, not at midspan. This is approximately √(1/3) × L.
Portal frames under lateral load experience combined bending and axial forces in columns and beams, not simple bending.
For fixed-fixed beam with UDL, FEM = wL²/12 at both ends (opposite in direction for equilibrium).
Release means removing redundant constraints/reactions to convert indeterminate structure into determinate one for analysis.
Three-hinged arch has 4 reaction components (2 at each support). Three hinges provide 3 moment equations. Total 4 independent equations.
For symmetric loading and equal spans, interior support moments are equal due to symmetry of structure and loading.
Propped cantilever has: fixed end (3 reactions: vertical, horizontal, moment) + prop reaction (1) = 4 total reactions.