Flashcards in Material definitions Deck (20):

1

## Plastic

### When deformed doesn't return to original position

2

## Elastic

### After deformation the material returns to its original position when the force is removed.

3

## Viscous drag

### The frictional force produced by a flowing fluid

4

## Turbulent flow

### Flow lines arent parallel, layers mixand contains eddies

5

## Tensile strain + equation

###
Extension per unit length

Strain = extension/original length

6

## Tensile stress

###
Forceper unit area

Nm-2

Stress =force / cross sectional area

7

## Terminal velocity

###
The constant velocity reached when weight equals upthrust + drag

Forces in equilibrium

8

## Ductile

### Undergoes lots of plastic deformation under tensile force

9

## Brittle

### Shows little plastic deformation before breaking

10

## Yield point

### A large increase in strain is seen for a small increase in stress

11

## Malleable

### Undergoes lots of plastic deformation under compressive force

12

## Upthrust

###
The upward force equal to the weight of fluid displaced.

Or the upward force due to fluid pressure

13

## Elastic limit

### Where it stops behaving elastically

14

## Hard

### Resistant to cutting , indentation and abrasion

15

## Tough

### Can absorb a lot of energy before it breaks

16

## Laminar flow

###
A flow pattern where all the flow elements flow in the same direction

Streamlines run parallel

17

## Young's modulus

###
Measure of stiffness

Units = Nm-2 =Pa

Young's modulus = stress / strain

18

## Limit of proportionality

###
Stops obeying hooke's law

Stops being a straight line

19

## Strong

### High ultimate tensile stress

20