Unit 2.3- Material Testing

Question 1

Axial Stress

Answer 1

A force with its resultant passing through the centroid of a particular section and being perpendicular to the plane of the section. A force in a direction parallel to the long axis of the structure.

Question 2

Breaking Stress

Answer 2

The stress required to fracture a material whether by compression, tension, or shear.

Question 3

Compression

Answer 3

When a material is reduced in volume by the application of pressure; the reciprocal of the bulk modulus.

Question 4

Deformation

Answer 4

Any alteration of shape or dimensions of a body caused by stresses, thermal expansion or contraction, chemical or metallurgical transformations, or shrinkage and expansions due to moisture change.

Question 5

Destructive Testing

Answer 5

Test methods used to examine an object, material, or system causing permanent damage to its usefulness.

Question 6

Elastic Limit

Answer 6

Maximum stress that a material will withstand without permanent deformation.

Question 7

Elongation

Answer 7

The fractional increase in a material’s length due to stress in tension or thermal expansion.

Question 8

Factor of Safety

Answer 8

The ratio of actual strength to required strength.

Question 9

Failure Point

Answer 9

Condition caused by collapse, break, or bending, so that a structure or structural element can no longer fulfill its purpose.

Question 10

Fatigue

Answer 10

The loss of the load-bearing ability of a material under repeated load application, as opposed to a single load.

Question 11

Hooke’s Law

Answer 11

The law stating that the stress of a solid is directly proportional to the strain applied to it.

Question 12

Modulus of Elasticity

Answer 12

The ratio of the increment of some specified form of stress to the increment of some specified form of strain, such as Young’s modulus, the bulk modulus, or the shear modulus. Also known as coefficient of elasticity, elasticity modulus, elastic modulus.

Question 13

Nondestructive Testing

Answer 13

Test methods used to examine an object, material, or system without impairing its future usefulness.

Question 14

Problem Solving

Answer 14

The ability to get answers to questions through a conscious, organized process. The answers are usually, but not necessarily, quantitative.

Question 15

Proportional Limit

Answer 15

point at which the deformation is no longer directly proportional to the applied force. Hooke’s Law no longer applies.

Question 16

Quality Control

Answer 16

Operational techniques necessary to satisfy all quality requirements; includes process monitoring and the elimination of root causes of unsatisfactory product or service quality performance.

Question 17

Reliability

Answer 17

The probability that a component part, equipment, or system will satisfactorily perform its intended function under given circumstances, such as environmental conditions, limitations as to operating time, and frequency and thoroughness of maintenance for a specified period of time.

Question 18

Resilience

Answer 18

A mechanical property of a material that shows how effective the material is absorbing mechanical energy without sustaining any permanent damage.

Question 19

Rupture Strength

Answer 19

Nominal stress developed in a material at rupture. Not necessarily equal to ultimate strength. Since necking is not taken into account in determining rupture strength, seldom indicates true stress at rupture.

Question 20

Shear Stress

Answer 20

A measure of how easily a material can be twisted.

Question 21

Standard Deviation

Answer 21

A statistical measurement of variability.

Question 22

Statistics

Answer 22

The collection and analysis of numerical data in large quantities.

Question 23

Strain

Answer 23

Change in the length of an object in some direction per unit.

Question 24

Stress

Answer 24

The force acting across a unit area in a solid material resisting the separation, compacting, or sliding that tends to be induced by external forces.

Question 25

Stress Strain Curve

Answer 25

Graphical representation of a material’s mechanical properties.

Question 26

Tension

Answer 26

The condition of a string, wire, or rod that is stretched between two points.

Question 27

Toughness

Answer 27

Mechanical property of a material that indicates the ability of the material to handle overloading before it fractures.

Question 28

Ultimate Stress

Answer 28

Sometimes referred to as tensile strength; determined by measuring the maximum load a material specimen can carry when in the shape of a rectangular bar or cylindrical can.

Question 29

Variance

Answer 29

The average of the squared differences from the mean.

Question 30

Pretensioning

Answer 30

A method of prestressing concrete whereby the tendons are elongated, anchored while the concrete in the member is cast, and released when the concrete is strong enough to receive the stresses from the tendon through bond.

Question 31

Prestressing

Answer 31

Refers to reinforcing concrete in which internal stresses have been introduced to reduce potential tensile stresses in the concrete resulting from loads.

Question 32

Force

Answer 32

An influence on a body which causes the body to accelerate; quantitatively, it is a vector, equal to the body’s time rate of change in momentum.