Draft

5.3Shear& Moment Diagrams 101

Thechangein moment between 1 and 2 ,
M 21 , is equalto theareaunder

theshearcurve betweenx 1 andx 2.

57 Notethatwe stillneedto haveV 1 andM 1 in orderto obtainV 2 andM 2 respectively.

58 Fig. 5.12and5.13further illustratesthevariationin internalshearandmoment under

uniformandconcentratedforces/moment.

Figure5.12: ShearandMoment Forcesat Dierent Sectionsof a LoadedBeam

Shear

Moment

Load

Shear

Positive Constant Negative Constant

Positive Constant Negative Constant Negative IncreasingNegative Decreasing

Negative IncreasingNegative Decreasing

Positive Increasing Positive Decreasing

Positive Increasing Positive Decreasing

Figure5.13:Slope RelationsBetweenLoadIntensity andShear,or BetweenShearandMoment