Sanklchand Patel College of Engineering Visnagar Structural Analysis II

 Prepared by  Patel Avni Bhailalbhai Guidance By:- Prof. Jayraj Rajput Bending Deformation, Strain and Stress in Beams

Key Points: 1Bending moment causes beam to deform. 2X = longitudinal axis 3Y = axis of symmetry 4Neutral surface – does not undergo a change in length 6.2 Bending Deformation and Strain

Key Points: 1Internal bending moment causes beam to deform. 2For this case, top fibers in compression, bottom in tension.

Key Points: 1Neutral surface – no change in length. 2All cross-sections remain plane and perpendicular to longitudinal axis. 3Neglect deformation of cros section within its own plane.

Radius of curvature Length = constant Length decreases

Says normal strain is linear Maximum at outer surface (where y = c)

6.2 Bending Stress – The Flexure Formula What about Stress???? Recall from section 6.1: Therefore, it follows that

Sum moments about cut: This is the moment of inertia, I

The Flexure Formula: Or in general: Max bending stress, psi Internal bending moment, lb-in Distance from NA to outer fiber, in Moment of inertia, in4

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