\[\begin{aligned}
R_A&=\frac{Pb}{L}\\
R_B&=\frac{Pa}{L}\\
L&=a+b
\end{aligned}\]
Variables
Raleft support reaction force (N)
Rbright support reaction force (N)
Papplied point load (N)
adistance from left support to load (m)
bdistance from load to right support (m)
Lbeam length (m)
Description
What is this formula?
This formula calculates the support reaction forces of a simply supported beam subjected to a single point load.
When to use it
Use this formula when determining support loads in beams and structures subjected to concentrated forces.
Example
Data:
P=1000 N
a=2 m
b=3 m
Formula:
Ra=(P*b)/L
Rb=(P*a)/L
Substitution:
L=2+3=5
Ra=(1000*3)/5
Rb=(1000*2)/5
Result:
Ra=600 N
Rb=400 N
Applications
Structural engineering
Beam design
Machine structures
Civil engineering