PDF 3

Question 1

Fill the blank.
_____ = mechanical properties that are desirable to
the designer, such as high strength, usually make
manufacturing more difficult

Answer 1

Dilemma

Question 2

Three types of static stresses to which materials can
be subjected:
1.Stretching the material (___)
2.Squeezing the material(___)
3.causing adjacent portions of the material
to slide against each other(___)

Answer 2

1 ==> Tensile
2 ==> Compressive
3 ==> Shear

Question 3

Fill the blank.
___ basic relationship that describes
mechanical properties for all three types

Answer 3

Stress-strain curve

Question 4

Determien the type of the test.
 Most common test for studying 
stress-strain relationship, 
especially metals 
 In the test, a force pulls the 
material, elongating it and 
reducing its diameter
 (left) Tensile force applied and 
(right) resulting elongation of 
material

Answer 4

Tensile Test

Question 5

What is engineering stress ?

Answer 5

S = F/Ao
S =Engineering Stress
F =Applied force
Ao = orginal area of test specimen.

Question 6

What is engineering strain ?

Answer 6

e = (L - Lo)/ (Lo)
e= Engineering Strain
L = length at any point during elongation.
Lo= orginal gage length.

Question 7

What happend in elastic reigon, when you remove the stress to the material ?

Answer 7

It’s returns orginal length.

Question 8

Fill the blank.
As stress increases, a point in the linear relationship
is finally reached when the material begins to yield
___ ___ Y can be identified by the change in
slope at the upper end of the linear region

Answer 8

Yield Point

Question 9

What is the other names of Yield Point ?

Answer 9

Yield Strength
Yield Stress
Elastic Limits

Question 10

What is this ?

== > Ability of a material to platstically strain without fracture.

Answer 10

Ductility

EL = (Lf - Lo ) / (Lo)

Question 11

What is the difference between Engineering Stress and True Stress ?

Answer 11

In engineering stress we use the original area but in True stress we use instantaneous area resisting the load.

Question 12

Fill the blank.
Note that true stress increases continuously in the
plastic region until necking
In the engineering stress-strain curve, the
significance of this was lost because stress was
based on the original area value
It means that the metal is becoming stronger as strain
increases
This is the property called _____

Answer 12

Strain hardening.

Question 13

Determien the type of the test.
-Applies a load that 
squeezes the ends of a 
cylindrical specimen 
between two platens

Answer 13

Compression Test

Question 14

Fill the blank

• Brittle materials do not ___

- They deform elastically until ___

Answer 14

Flex

Fracture

Question 15

Fill the blank.
- ____ common with ceramics
and metals at low temperatures, in which
separation rather than slip occurs along certain
crystallographic planes

Answer 15

cleavage

Question 16

What is hardness ?

Answer 16

Resistance to permanent indentation(girinti)

Question 17

Determien the type of the test.
Commonly used for assessing material properties
because they are quick and convenient
Variety of testing methods are appropriate due to
differences in hardness among different materials

Answer 17

Hardness Tests

Question 18

Fill the blank.

Most well-known hardness tests are ____ and ____

Answer 18

Brinell and Rockwell.

Question 19

Determien the type of the test.
- Widely used for 
testing metals and 
nonmetals of low to 
medium hardness

Answer 19

Brinell Hardness Test

Question 20

Determien the type of the test.
A cone shaped indenter is pressed into specimen
using a minor load of 10 kg, thus seating indenter in
material
Then, a major load of 150 kg is applied, causing
indenter to penetrate beyond its initial position

Answer 20

Rockwell Hardness Test

Question 21

Fill the blank.
____ is a measure of the internal friction when
velocity gradients are present in the fluid

Answer 21

Viscosity