The objectives of this experiment are to determine the failure strain of a strand of spaghetti and test the validity of Euler’s theory for the large deflections of an elastic lamina. The educational objectives are to introduce the concept of uncertainty in measurement and to learn something about strain in bending.
In this experiment, students will verify the consequences of static equilibrium for a weight suspended from a cable. In a second part, they will determine the force/deflection relationship for a redundant structure built up with two cables under pretension. In contrast to the first part, the theory for the second experiment will not be provided until later in the course.
The objective of this experiment is to measure the Elastic Modulus of steel. The experiment comes in two parts. In the first part of the experiment, students will subject an ordinary steel reinforcing rod to a tension test using a testing machine designed specifically for that purpose. The BLH machine dates from the 1950s but its mechanical subsystems still function well enough for our purposes.
In the second part, students will do a tension test of a stainless steel rod, loading the specimen using the dead weights available in the lab but measuring displacement using the LVDT, Linearly Variable Differential Transformer.
Truss Deflection (PDF)
Students will load a truss structure vertically at various pairs of joints (symmetrically disposed with respect to the length) and measure the vertical displacements of two or three joints. The objective is to compare the results obtained from analyses which model the structure as a truss (i.e., with friction-less pinned joints), with experiment.
Students will conduct a compressive test on a cylinder of concrete to observe its force/deformation behavior and determine its strength. A second test gives, indirectly, the tensile strength.
Beam Deflection and Stresses (PDF)
The objective is to verify the predictions of engineering beam theory in so far as that theory defines the centerline deflection and extreme values of the normal stress. Students will determine the relative stiffness of two aluminum beam test specimens of equal cross sectional area but different cross-sectional shape and see how they conform to theory.
Elastic Buckling (PDF)
The objective is to demonstrate local elastic buckling within a truss structure and to compare experimental results with Euler buckling theory.