Faculty of Applied Science and Technology
ENGI23413 Mechanics of Materials
Lab Report #: 2
Title of Experiment:Shear Strength
Group Members present (with Initials):
1:Gurpreet Singh (….) 2:Jaskirt Singh Na (….) 3: Amninderjeet Singh(….) 4:Rajbir Singh(….) 5:Gurtej Singh(….) 6:Shiv Kumar(….)
Date of Experiment: . 12/09/2012
Date of Submission: 26/09/2012; Time: ……….
Declaration: I/we hereby declare that the work presented in this report is mine/ours and not plagiarized or copied except where indicated and referenced : signatures: 1...................; 2......................; 3…………………; 4………………; 5……………..;6………………..
TITLE- SHEAR STRENGTH EXECUTIVE SUMMARY
The purpose of this lab was to find the shear strength of three materials i. e. Steel ,Brass and Aluminum. The values of the shear strength from the table indicate that the steel has maximum shear strength whereas aluminum has least shear strength. OBJECTIVE
The objective was to know how important is the shear strength while making designs by testing shear strength of three materials. THEORY
According to H.W. Morrow and Robert P. Kokernak, Statics and Strength of Materials, eighth Edition:
Shear stress is a type of stress which is caused by two forces acting parallel to the cross sectional area and these forces are acting in opposite directions.
Shear strength is the maximum force divided by cross sectional area, where the forces are parallel to the area and both are in opposite direction.
The relation between shear strength and tensile strength is that shear strength is about three-fourths of tensile strength.
EQUIPMENT AND MATERIALS
Figure 1: Vega Hydraulic Shear Machine and Materialsvernier caliper 1)Vega Hydraulic Shear Machine
2)Double Shear fixture
3)Aluminum, Brass and Cold Rolled Sample
4)Vernier-Caliper(in fig. 2)
The Vega shear machine is used in materials testing and can apply loads in tension and compression. In our application a round stock was loaded into a double shear fixture and a compressive force was applied to the fixture which created a double shear force on the material. The machines dial indicates the applied load and maximum load that is applied to the specimen.
1)Each of the testing material was measured and recorded using the vernier caliper. 2)A demonstration regarding the safe operation of the Vega testing machine was provided by a trained Technologist. 3)The steel sample test sample was inserted into the double shear fixture. It was slightly protruded at one end of the fixture so the specimen could be reused. 4)The loaded double shear fixture was loaded into the centre of the machine table. 5)The machine guard was closed.
6)Both needles on the analog scales were set to zero.
7)Loading of the fixture was done gradually by pumping the hydraulic lever until the sample completely sheared. 8)The maximum force applied was recorded from the analog scale. 9)Load was continued to be applied to the fixture until the sheared slug passed to the bottom relief area of the fixture. 10)The hydraulic pressure was released from the machine allowing the fixture to be unloaded. 11)The double shear fixture was taken apart by sliding the movable part away from the holder and discarding the sheared slugs. 12)Steps 3-11 were repeated on the same sample to obtain two sets of results. 13)Steps 3-12 were repeated on the two samples of brass and aluminum
Table # 1 Readings observed during experiment
Material| Diameter(INCHES)| Maximum TEST 1|...