Chapter 6: Mechanical Properties Of Metals

Question 1

What mechanical behavior is used…
A load that is static or changes relatively slowly with time and is applied evenly over a cross section or surface of a member

Answer 1

Simple stress-strain

Question 2

An applied tensile load produces what?

Answer 2

An elongation and positive linear strain in a material

Question 3

An applied compressive load produces what?

Answer 3

A contraction and negative linear strain in a material

Question 4

An applied shear load is defined by what

Answer 4

The angle (theta)

Question 5

An applied shear load is applied where?

Answer 5

Parallel to the material’s surface in opposite directions on opposite sides of

Question 6

Torsional forces produce what?

Answer 6

A rotational motion in opposite ends of a material

Question 7

Torsional strain is defined by what?

Answer 7

The angle of twist

Question 8

What is gauge length used for

Answer 8

Ductility calculations

Question 9

What is the equation for engineering stress?

Answer 9

Engineering Stress =F/A0

Where:
UNITS: megapascals, MPa (SI)
1 MPa = 10^6 N/m^2
F= the instantaneous load applied perpendicular top the specimen
A0=the original area before adding the load (m^2 or in^2)

Question 10

What is the equation for engineering strain?

Answer 10

Engineering Strain= (li-lo)/lo
=change in l/lo

Where:
l0= original length before adding the load
li=instantaneous length
UNITS: unit less

Question 11

During a tensile test, a dog bone shaped specimen is used because——.

• deformation is confined to the narrow center region, and the shape reduces the likelihood of fracture at the specimen’s ends.
• the shape reduces the likelihood of of fracture at the specimen’s ends
• deformation is confined to the narrow center region

Answer 11

Deformation is confined to the narrow center region, and the shape reduces the likelihood of fracture at the specimen’s ends

Question 12

For a tensile test specimen, gauge length is the specimen’s——.

• initial length between the testing apparatus’s grips
• measured instantaneous length actively observed during the test
• reduced section including the tapering regions
• an initial length slightly shorter than the initial reduced specimen length

Answer 12

An initial length slightly shorter than the initial reduced specimen length

Question 13

What does the engineering stress equation used for?

Answer 13

Tension and compression

Question 14

What is the engineering strain equation used for?

Answer 14

Tension and compression

Question 15

A tensile load F is applied to two specimens, where A1 is less than A2. The stress on A1 is——the stress on A2.

• greater than
• the same as
• less than

Answer 15

Greater than

Question 16

Stress is measured in——, and strain is——.

• Megapascals, unitless
• newtons, unitless
• megapascals, meters

Answer 16

Megapascals, unitless

Question 17

A material specimen has an initial length l0=0.052m. After applying a load, the specimen’s length is li= 0.053m. The strain is =——.

• 0.019
• 0.001
• -0.019

Answer 17

0.019