Reference no: EM132866830

Aim & Objectives

The aim of this lab is to develop an appreciation of the principles of mechanical testing, in particular uniaxial tensile testing of metals and polymers, and how it is used to measure mechanical properties of materials.

Upon successful completion of this lab, you will be able to:
• Undertake tensile testing to measure mechanical properties associated with elastic and plastic deformation;
• Describe and explain qualitative aspects of mechanical properties and mechanical testing
• Record and present experimental data
• Plot graphs, and extract values.
• Improve technical reporting skills.

The technical objective of this lab is to determine the tensile deformation behaviour of two metal samples and two polymer samples (steel, aluminium, polypropylene and Perspex acrylic) using an Instron tensile tester, and compare the mechanical properties measured with "text-book" values.

Background
Tensile Test is a common, standard mechanical test in Engineering. The tensile strength of a material is essentially its ability to withstand tensile loads without failure. It provides essential details about a material and its related properties (strength and ductility under axial tensile stress), which help analyze and design different engineering structures. These properties are obtained by cautiously carrying out designed lab experiments that imitate the material's term of service as precisely as possible. In the real world, many factors affect the nature in which forces are applied to a material. When designing machines and other equipment, it is crucial to consider these mechanical properties. Although uncontrolled factors such as temperature, weather, and time constraints affect the design process, it is necessary to know these properties.

2. Objective
The experiment aimed to determine the tensile deformation behaviour of two metal samples (mild steel and aluminum alloy) and two polymer samples (polypropylene and Perspex acrylic) when force is applied. Moreover, to obtain the following mechanical properties from the stress-strain graphs: Modulus of Elasticity, yield stress, strain at failure, and the ultimate tensile strength.

3 Theory
Robert Hooke suggested a linear relationship between an applied force (F) and the resulting extension (ΔL) in a material. Under these conditions, the object returns to its original shape and size upon removal of the load.

Attachment:- Structural Materials.rar