Simple Beam - Two Unequal Point Loads Unequally Spaced

on . Posted in Structural Engineering

diagram Symbols

  • Bending moment diagram (BMD)  -  Used to determine the bending moment at a given point of a structural element.  The diagram can help determine the type, size, and material of a member in a structure so that a given set of loads can be supported without structural failure.
  • Free body diagram (FBD)  -  Used to visualize the applied forces, moments, and resulting reactions on a structure in a given condition.
  • Shear force diagram (SFD)  -  Used to determine the shear force at a given point of a structural element.  The diagram can help determine the type, size, and material of a member in a structure so that a given set of loads can be supported without structural failure.
  • Uniformly distributed load (UDL)  -  A load that is distributed evenly across the entire length of the support area.

 

sb 11D

Simple Beam - Two Unequal Point Loads Unequally Spaced Formulas

\( R_1 \;=\; V_1 \;=\; [\; P_1 \; (  L \;- \;a ) \;] + (P_2\; b \;/\; L) \) 

\( R_2 \;=\; V_2  \;=\; P_1 \;a +[\; P_2 \; ( L - b ) \;] \;/\; L \) 

\( V_x  \; [\; a < x  < ( L - b ) \;] \;=\; R_1 - P_1  \) 

\( M_1 \; (max.\; when\;  R_1 < P_1 )  \;=\; R_1\; a  \)

\( M_2 \; (max.\; when\;  R_2 < P_2 ) \;=\; R_2\; b \)

\( M_x \; (max.\; when\;  x < a )  \;=\; R_1\; x  \)

\( M_x \; [\; max.\; when\; a < x < \;(  L - b ) \;]  \;=\; R_1\; x  - [\;P_1\; ( x - a ) \;]  \)

Symbol English Metric
\( \Delta \) = deflection or deformation \(in\) \(mm\)
\( x \) = horizontal distance from reaction to point on beam \(in\) \(mm\)
\( a, b \) = length to point load \(in\) \(mm\)
\( M \) = maximum bending moment \(lbf-in\) \(N-mm\)
\( V \) = maximum shear force \(lbf\) \(N\)
\( \lambda  \)   (Greek symbol lambda) = modulus of elasticity \(lbf\;/\;in^2\) \(Pa\)
\( I \) = second moment of area (moment of inertia) \(in^4\) \(mm^4\)
\( R \) = reaction load at bearing point \(lbf\) \(N\)
\( L \) = span length of the bending member \(in\) \(mm\)
\( P \) = total concentrated load \(lbf\) \(N\)

 

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Tags: Beam Support