Structural elements calculators
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Find shear and moment for simply-supported beam

Jonathan Ochshorn


Directions: Enter values for loads and their positions along the beam, using any consistent units. To eliminate a load, set its magnitude to zero. Refer to the diagram for variable names. For example, use ft for distances; use either lb/ft and lb units, or kips/ft and kip units for loads; the reactions will be in either lb or kips; the shear will be in either lb or kips; and the moment will be in either ft-lb or ft-kips, depending on your choice. Loads are assumed to act in a downward direction, with reactions acting in an upward direction. Upward-acting loads should be entered as negative numbers; a negative reaction indicates that its direction is actually downward-acting rather than upward-acting. Positive moments are those corresponding to tension at the bottom of the beam; negative to tension at the top. Positive shear corresponds to a downward-acting force on the right side of a free-body diagram cut where the shear force is being measured; negative to an upward-acting force.

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More detailed explanations and examples can be found in my text.

beam dimensions and load magnitudes
Fig. 1. Beam geometry (lengths) and magnitude of loads