Internal Loadings in Structural Members: Problem Solving

Consider a beam OC of 5 kilonewton, inclined at an angle and supported at both ends. Determine the internal loadings at point A.

The joints supporting the beam experience reaction forces. By using the moment equation about point O and substituting the values, the reaction force at point C can be determined.

The weight of the beam acts at the center and can be resolved in its components.

Now, consider an imaginary line passing through point A, dividing the beam into two sections. Next, draw a free-body diagram of the segment with the minimum unknown forces.

By recalling the equilibrium equation and substituting the values of forces along the horizontal direction, the normal force in the section can be determined.

The negative sign indicates the opposite direction of the normal force acting on the cross-section.

Similarly, by using the equilibrium equation and substituting the values of the vertical forces, the shear force in the section can be determined.

Finally, using the moment equation, the magnitude of the moment at point A can be determined.