Engineering & design · University
Support reaction for a simply supported beam
One downward point load W acts a distance a from left support A; beam self-weight is neglected.
Method and conditions
One downward point load W acts a distance a from left support A; beam self-weight is neglected.
RB L = W a
Worked examples
A simply supported beam of span 17 m carries 5000 N downward at 1 m from support A. Neglect self-weight. Find upward reaction at support B. Round the final result to 4 decimal places if needed. Answer in N.
Take moments about A: RB(17)=5000(1).
294.1176 N
A simply supported beam of span 5 m carries 100 N downward at 4 m from support A. Neglect self-weight. Find upward reaction at support B. Round the final result to 4 decimal places if needed. Answer in N.
Take moments about A: RB(5)=100(4).
80 N
Try it
A simply supported beam of span 14 m carries 5700 N downward at 9 m from support A. Neglect self-weight. Find upward reaction at support B. Round the final result to 4 decimal places if needed. Answer in N.
A simply supported beam of span 9 m carries 900 N downward at 5 m from support A. Neglect self-weight. Find upward reaction at support B. Round the final result to 4 decimal places if needed. Answer in N.
Check your work
Answers and marking notes
- 3664.2857 N
Take moments about A: RB(14)=5700(9).
- 500 N
Take moments about A: RB(9)=900(5).
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