L14_ PureBending- fall 10-1

# L14_ PureBending- fall 10-1 - EAS 209-Fall 2010 Instructors...

This preview shows pages 1–4. Sign up to view the full content.

EAS 209-Fall 2010 Instructors: Christine Human 9/17/2010 1 Lecture 14– Beams: Pure Bending Lecture 14 Pure Bending Structural members and loads Axial Loads (bars and cables) CHAPTERS 2 Torsional Loads (shafts and tubes) CHAPTER 3 Bending Loads (beams) CHAPTERS 4,5,6,8,9 Todays’s Objective Define pure bending Develop elastic flexure formula I My x = σ Today’s Homework Relationship between normal stress and applied moment EAS 209-Fall 2010 Instructors: Christine Human 9/17/2010 2 Lecture 14– Beams: Pure Bending Classification of Beams Typical Beams For now, analyze only statically determinate beams Supports and reactions Roller - vertical reaction Pinned - vertical and horizontal reaction Fixed - vertical, horizontal and moment reaction

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
EAS 209-Fall 2010 Instructors: Christine Human 9/17/2010 3 Lecture 14– Beams: Pure Bending Internal Forces Sign Convention M M’ M’ Hogging Sagging +ve moment Compression in top Tension in bottom -ve moment Tension in top Compression in bottom Transverse Loading : Concentrated or distributed transverse load produces internal forces equivalent to a shear force V and a bending moment M Internal forces V and M can be determined from equilibrium = = = = Px M M P V F B y 0 0 EAS 209-Fall 2010 Instructors: Christine Human 9/17/2010 4 Lecture 14– Beams: Pure Bending We will start our analysis of beams by looking at a prismatic member subjected to pure bending . Consider the beam below (which represents a barbell held overhead by a weightlifter) Within the central portion of the beam M =constant, V =0. The center section is in Pure Bending Shear force diagram 80 lb 80x12=960 lb.in Bending moment diagram Note how the beam will deform – center portion in pure bending will form a circular arc
EAS 209-Fall 2010 Instructors: Christine Human 9/17/2010 5 Lecture 14– Beams: Pure Bending Symmetric Member in Pure Bending The three equations are in terms of the normal stress, σ x . But the stress distribution is statically indeterminate, so we need to consider deformations. Consider a prismatic

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 8

L14_ PureBending- fall 10-1 - EAS 209-Fall 2010 Instructors...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online