The purpose of the experiment was to determine the values of the ultimate tensile strength, yield point, Young’s modulus and ductility of types of steel, aluminium, PMMA and nylon. Stress-strain graphs were also plotted in order to view the general behaviour of the materials. The various regions (elastic to plastic, then necking to fracture) and gradients were analysed to determine that the steel had the greatest strength in tension, while nylon was the most ductile material.
The period of straight lines indicates when the materials were behaving elastically (and so shows the yield at the right hand end of the line for the first four). After that point (shown only by the first four), the material behaves plastically, until it breaks at the ultimate tensile strength point, when the graph stops/suddenly drops. Note on (c) the upper and lower yield point phenomena.
Due to the lab being repeated for other years, the full report has not been uploaded. It is however available on request, using the contact details available.