Within a singly reinforced concrete beam____________?
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Answer: C. Plane sections transverse to the centre line of the beam before bending remain plane after bending
Explanation
Bernoulli's hypothesis forms the kinematic foundation of classical beam bending theory. Plane cross-sections remain plane and perpendicular to the neutral axis after deformation. Strain varies linearly across the depth from the neutral axis. Flexural theory assumes uniform deformation across transverse beam cross-sections. Bending causes longitudinal fibers to elongate or shorten proportionally. This kinematic assumption simplifies the calculation of internal bending stresses.
Structural analysis software and hand calculations rely entirely on this foundational principle. Deviations occur only in deep beams or near concentrated load application points. Validating this assumption ensures predictable structural behavior in concrete frames. Concrete bears most compression, but this statement is not the kinematic bending assumption. Embedded steel does not possess initial stresses unless pre-stressing is applied. Elastic moduli differences describe material properties rather than kinematic cross-section behavior.
- Subject
- Engineering
- Category
- Civil Engineering
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- —
- Difficulty
- medium
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