To determine the reaction of a beam under various loadings

To determine the reaction of a beam under various loadings

Apparatus

Frame fitted with vertical spring balance holding a ground a graduated horizontal beam, stirrups, spirit level weights

Procedure

Attach a few stirrups to various points of the beam, make it horizontal by means of sprit level and thumb nuts, and note the reading in the balances. These are the zero readings. Now attach various loads W₁, W_2, W_3, W₄ to the stirrups again make the beam horizontal. The perpendicular distance d₁, d_2, d_3, d₄ of these vertical loads from C & D respectively R₁ and R₂. Then neglecting the weight of stirrups and beam and taking the moment about point C, the sum of clockwise moment must be equal to the sum of anticlockwise moment. From this we get R_2. Further R₁+ R₂= W₁+ W₂ + W₃ + W₄ AND hence R₁ can also be found. Compare these values of R₁ and R₂ with the balance readings and enter the table: 

Observation and calculations

Reaction R2
By calculation moment about C							By Cal R2	By EXP R2	By Cal R1	By EXP R1
	Forward			Backward
	Force (N)	Distance (m)	Moments (N-m)	Force (N)	D     (m)	M  N-m
1
2
3
4
5