4.20 : Distributed Loads: Problem Solving

Beams are structural elements commonly employed in engineering applications requiring different load-carrying capacities. The first step in analyzing a beam under a distributed load is to simplify the problem by dividing the load into smaller regions, which allows one to consider each region separately and calculate the magnitude of the equivalent resultant load acting on each portion of the beam. The magnitude of the equivalent resultant load for each region can be determined by calculating the area of the respective regions, which represents the force exerted by the load in each region.

Next, locate the position of each resultant load on the beam. This can be done by finding the centroids of the regions, which are the points where the mass of the regions can be considered concentrated. The individual resultant loads act at these centroids, exerting their force at specific points along the beam.

The equivalent resultant load for the entire beam can be calculated with the magnitudes and positions of the determined individual resultant loads. This involves adding the individual resultant loads of the different regions to obtain the overall equivalent resultant load acting on the beam.

The next step is to determine the moment about a specific point, usually the fixed end of the beam. The moment measures the rotational effect of the force acting on the beam. The resultant moment can be determined by adding the individual moments acting due to each load. The moment of each load is equal to the product of the force and its distance from the specified point.

By recalling the moment principle, the moment of the equivalent resultant load about the specified point equals the product of the equivalent resultant load and the distance from that point.

By rearranging the equation and substituting the terms, the location of the equivalent resultant load along the beam can be determined.