What is pure bending.

 Pure bending is a condition in which a structural element, typically a beam, is subjected to a bending moment without any accompanying axial forces or torsion. In pure bending, the internal stresses and deformations in the material are caused solely by bending, and there is no axial stretching or twisting of the beam. This idealized condition is often assumed in the analysis and design of structures to simplify calculations.

In pure bending, the deformation of the beam is characterized by a uniform curvature along its length. The cross-sections of the beam remain plane (they do not warp or twist), and the material experiences tensile stresses on one side and compressive stresses on the other side. The neutral axis, which is a line through the cross-section that experiences neither tension nor compression, remains unchanged in length during pure bending.

The equation governing pure bending is derived from the flexural equation. For a beam in pure bending, the bending moment ($�$), flexural rigidity ($��$), and curvature ($1\mathrm{/}�$) are related by:

Pure bending is a useful concept for understanding and designing structures, and it simplifies the analysis of bending behavior in beams. However, in reality, it's challenging to achieve perfect pure bending because there are often additional loads, such as axial forces or torsion, acting on structures. Engineers use the concept of pure bending as a starting point and then consider other factors and loading conditions to refine their analyses and designs.

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