DESIGN OF EXPERIMENTS IN A LABORATORY OF MECHANICS OF ENGINEERING MATERIALS

The design of different experiments to learn mechanics of materials is presented in this work.
Mechanics of materials (or strength of materials) is a discipline that is imparted in the program of Mechanical Engineering. The concepts and procedures that are studied in this subject are the base of the ones that are used to calculate buildings and machines.
For the best understanding of the mechanical behaviour of different types of elements that work in buildings and machines, some experimental sets have been designed for this purpose in our laboratory.
They have been designed for the study of members of the frameworks subjected to axial forces (tension or compression), analysis of the stress distribution in structural members subjected to torsion, design of beams for strength and deflection, and other type of structural components in frames and machines.
In this work, the designed experiments are explained in a detailed way: the device to study beams, the designed frame to study the basic forms of deformation and displacement of solid bodies: tension, compression, twisting and bending. And a pressure vessel to evaluate the variation of stress and strain in its walls.
The experimental technique that is used for the calculation of the deformations that take place in each member is the extensometry, with the application of strain gauges for the determination of strain at a point on the surface of a member.
The number of students that work in the laboratory is around twenty. They are distributed in four groups. While two of the groups are taking measurements, the other two groups are calculating the necessary parameters to evaluate the mechanical behaviour of the components that are being analyzed.
It is interesting to observe that the knowledge of the mechanical behaviour of materials really improves in this subject by using the designed experiments. We continue designing experimental sets for the study of mechanics of materials with simple ideas and concepts that are presented in this article.