Purpose
The purpose of this laboratory is to become familiar with the SM104 Beam Apparatus by
first verifying its sensitivity and accuracy. The second part of the lab will focus on using the
SM104 Beam Apparatus to determine the deflection of point-loaded simply-supported beams
made of steel, brass or aluminum. Using the deflection measurements, an examination of the
relationship between deflection and material properties will be shown along with a comparison
of the materials based on their strengths and deflections, both theoretical and experimental. The
last objective of this laboratory is to verify the theory of pure bending using the SM104 Beam
Apparatus.
Introduction
Engineers use beams to support loads over a span length. These beams are structural
members that are only loaded non-axially causing them to be subjected to bending. “A piece is
said to be in bending if the forces act on a piece of material in such a way that they tend to
induce compressive stresses over one part of a cross section of the piece and tensile stresses over
the remaining part” (Ref. 1). This definition of bending is illustrated below in Figure 1.