Engineered System Material

This report aims to analyse and discuss the results of carrying out tensile tests for two materials, in this case Mild Steel and Nylon. The purpose of this is to use the information generated to calculate Young’s Modulus, Yield Stress, Tensile Strength, and Percentage Elongation. These properties must be known before designing a product using the materials tested, because the anticipated behaviour of the material must be suitable for the design specification, with a margin left for safety.

Experiment Two: Stiffness Report from laboratory work performed on 12 May 2011 as a part of the unit of study CIVL2201 Structural Mechanics

1) Of all the sample materials tested during the lab, the AISI-1020 Cold Rolled Steel was found to be the strongest. Moreover, between the two samples of AISI-1020 Cold Rolled steel, the sample without the neck was found to be stronger. This was observed by calculating the ultimate tensile strength for all the samples used during the experiment. As a result, the higher the ultimate tensile stress the material endured, the stronger the material was. The ultimate tensile stress calculated for the AISI-1020 Cold Rolled was 563 MPa which was the highest of all. Therefore, concluding that the AISI-1020 Cold Rolled without a neck region was the strongest material.

Several mechanical tests have to be applied for measuring static and dynamic properties of materials and most of them involve applying a force to the material and measuring its displacement. Through these tests, measuring the stress applied and the resulting strain, it is possible to calculate material properties such as the Young modulus, the physical parameter corresponding to the material stiffness.

THEORY: Please refer to P5: Plastic Properties of Sheet Metal lab manual for detailed Theory. [1]

All testing was carried out using DMA with a cantilever setup. Two different tests were carried out. For the first test, the HDPE was held at a constant temperature of 31°C and varying stresses were applied for two seconds at a time, during which the strain in the sample was recorded.

Zajac, 1990; Meyer et al., 2002). The reminder of this article is structured as follows:

Over the course of the last few weeks my lab partner and I have conducted tests on different material of metal rods. During this time, we collected data regarding the stress and strain of the given materials and were able to come up with a report including statements about the significance and importance of their designated yield strength.

This test is performed at different temperatures to more closely evaluate the service conditions as most of the properties of the material are temperature dependent such as ductility or yield behavior

From the stress-strain curve of the tensile test, the values which can be found are Modulus of Elasticity, Yield Strength, the Tensile Strength, Percentage of Elongation and the Reduction in Area. Also the Toughness, Resilience, Poisson’s ratio can be found by using the tensile test.

The nine components above can be summarized as below (Dick, W., & Carey, L. (1996);

Comparison using the {110} slip systems or a combination of both {110} and {112} slip systems does not give the same correlation. The rotation of tensile axes can also be explained by the dominance of {112} slip systems at yield [48].

The stress-strain relationship of the material can be determined through this process. And properties like ultimate tensile strain, tensile modulus of elasticity, Poisson’s ratio can be obtained.

Manufacturing process is a process of making a raw material to be finished good or semi-finished good so that the materials will have added value. The product could be made by various ways, such as:

The test for the compressive strength on cubes were measured at 7, 28 and 56 days of curing as per IS : 516 1959[14], and the testing is done for the split tensile strength of cylinder as per IS : 5816 1999[14]at 7, 28and 56 days of curing.