The STR4 assembly is aimed to investigate and visualize the deflection of simple beams and cantilevers. In this experiment, hanger and masses are applied on the beam and the deflection at a specific point of the beam is measured by a transducer and displayed on a digital dial test indicator.
One experment that we conducted using the STR4 was on simple beam deflections. Specifically, this experiment aims:
- To determine the maximum deflection of a simple beam with length, L, due to a concentrated load P with varying magnitude applied at mid span.
- To find the relationship between the maximum deflection and a point loading, P, applied at mid span.
- To compare the maximum deflections of two types of beams with different materials and cross-section properties and determine the effect of these properties on beam deflection.
Each group was assigned a specific length of the beam and two types of materials to test. There were three types of materials available for testing: Aluminum. Brass and Steel.
The maximum or midspan deflection were measured for varying midpsan load. Graphs showing both the experimental and theoretical deflections were drawn and compared. The figures below show a comparison of the deflections for the three types of materials. The steel beam has the least deflection while the Aluminum beam has the largest deflection. The theory of elastic deflection of beams was confirmed through the experiment.