Tensile Test Experiment

UNIVERSITI TENAGA NASIONAL

TENSILE TESTING

MEMB221 – MECHANICS AND MATERIAL LAB

SEMESTER 1 2013/14

GROUP MEMBERS: HARWINDER SINGH GREWAL ME087900 DAVEEN A/L MAHAINDRAN ME087885

SECTION : 01

GROUP : 8

INSTRUCTOR : NOOR ZAIMAH Binti MOHD MOKTHAR

Performed Date Due Date Submitted Date

1 August 2013 19 August 2013 19 August 2013

TABLE OF CONTENTS

Summary 3

Objective 4

Theory 5

Equipment 7

Procedure 10

Data and Observations 11

Results and Analysis 14

Discussions 17

Conclusions 18

References 19

SUMMARY

From this experiment 1 tensile test we have tested two materials

These tests are most commonly conducted for metals at room temperature. There are three principal ways in which the load may be applied: tension, compression and shear.

Tension is one of the most common mechanical stress-strain tests. The stress-strain diagram shows the different behaviour of the individual materials particularly clearly. Each material has a characteristic pattern of stress and strain. A standard specimen is deformed, usually to fracture with a gradually increasing tensile load that is applied uniaxially along the long axis of a specimen. Most of the tension tests for metals are conducted according to the ASTM Standard E 8 and E 8M, “Standard Test Methods for Tension Testing of Metallic Materials”.

HOOKE’S LAW

For most tensile testing of materials, you will notice that in the initial portion of the test, the relationship between the applied force or load and the elongation the specimen exhibits is linear. In this linear region, the line obeys the relationship defined as

Screw down the gripping head with the short bolt and with the pressure pad. Gripping head with long bolt at the top.

Insert the required sample. Length Lo of the sample between two marks is measured and take note. Screw the upper and lower gripping head. Tighten the upper gripping head with hand until the gripping head is tight without slack in the upper cross member.

Dial gauge is fixed It is adjusted and push the dial gauge upper until the tracer pin touches the drive. Set the scale to zero and the maximum force pointer to zero.

Experimental steps

Slowly and constantly loaded by rotating the hand wheel. Application of the force should spread over a time interval of 5-10 minutes. It is important to avoid sudden, jerky force application. Observe the dial gauge and the sample. Read the force from the display every 0.1 mm and make note of it with the corresponding extension. From 1 mm extension the reading interval can be extended to 0.2 mm. Monitor the sample and note when constriction begins. From now on, the force will no longer increase, but instead will tend to