Stress

Question 1

T or F
Stress can be applied in all directions.

Answer 1

T

Question 2

4 main practical applications of studying stress.

Answer 2

Earthquakes, Oil Well Blowouts, Plate Tectonics, and Landslides, etc.

Question 3

Type of stress that occurs from forces acting perpendicular (or normal) to a material’s surface, resulting in tension or compression.

Answer 3

Normal Stress

Question 4

Type of stress that comes from forces acting parallel to the surface, causing sliding or twisting action.

Answer 4

Shear Stress

Question 5

The distribution of internal forces within a body.

Answer 5

Stress

Question 6

Magnitude of forces within a body.

Answer 6

Stress

Question 7

Two types of Stress?

Answer 7

Normal and Shear

Question 8

When a force acts perppendicular to a surface, it exerts ______ stress.

Answer 8

Normal

Question 9

Kind of stress that starts from inside, then exerts outwardly.

Answer 9

Tensile Stress

Question 10

Kind of stress that starts from outside, then exerts inwardly.

Answer 10

Compressive Stress

Question 11

In geology, tensile stress is represented by a __________ sign.

Answer 11

Negative

Question 12

In geology, compressive stress is represented by a __________ sign.

Answer 12

Positive

Question 13

When a force acts parallel to a surface, it exerts ________ stress.

Answer 13

Shear

Question 14

T or F
Stress allows us to predict when an object will fail.

Answer 14

T

Question 15

Formula of stress.

Answer 15

Force / Area

Question 16

Changes the velocity of a body.

Answer 16

Force

Question 17

Formula for force.

Answer 17

Mass * Acceleration

Question 18

Type of force exerted to the surface of the body.

Answer 18

Surface Force

Question 19

Type of force exerted throughout the body.

Answer 19

Body Force

Question 20

Relationship between stress and strain; describes how maerials will deform.

Answer 20

Young’s Modulus

Question 21

Formula of Young’s Modulus

Answer 21

Rise / Run (Slope)

Question 22

A structure formed by brittle deformation and compressive stress.

Answer 22

Reverse Fault

Question 23

A structure formed by brittle deformation and tensile stress.

Answer 23

Normal Fault

Question 24

A structure formed by brittle deformation and shear stress.

Answer 24

Reverse Fault

Question 25

A structure formed by ductile deformation and compressive stress.

Answer 25

Folds

Question 26

A structure formed by ductile deformation and tensile stress.

Answer 26

Boudins

Question 27

A structure formed by ductile deformation and shear stress.

Answer 27

Ductile Shear Zone

Question 28

Response of a body to stress.

Answer 28

Deformation

Question 29

Formula of Strain.

Answer 29

Change in Volume / Volume

Question 30

Sign attributed to stresses plotted clockwise from the z axis.

Answer 30

Negative

Question 31

Sign attributed to stresses plotted counterclockwise from the z axis.

Answer 31

Positive

Question 32

Defines the state of stresses at a point inside a material in its deformed state.

Answer 32

Stress Tensor

Question 33

Represents the internal distribution of internal stresses.

Answer 33

Stress Tensor

Question 34

Non-hydrostatic component which produces distortion.

Answer 34

Deviatoric Stress

Question 35

Assumes the potential for distortion.

Answer 35

Differential Stress

Question 36

Hydrostatic component which produces dilation.

Answer 36

Mean Stress

Question 37

An isotropic component, which is a type of deformation mechanism and dilation. (Change in Volume) e.g. Lithostatic Pressure

Answer 37

Mean Stress

Question 38

The greater the ___________ ___________ is, the greater the potential for distortion.

Answer 38

Differential Stress

Question 39

An anisotropic component, which produces the distortion of a body. (Change in Shape) e.g. Hydrostatic Stress or Pressure

Answer 39

Deviatoric Stress

Question 40

_________ _________ defines an ellipse; ellipticity depends on the state of the stress.

Answer 40

Stress Vectors

Question 41

It tells about the state of stress at a given point in a rock.

Answer 41

Stress Ellipsoid

Question 42

Only 1 non-zero principal stress.

Answer 42

Uniaxial Stress

Question 43

1 principal stress is = 0, the other 2 are not.

Answer 43

Biaxial Stress

Question 44

3 non-zero principal stresses.

Answer 44

Triaxial Stress

Question 45

2 of the principal stresses are equal.

Answer 45

Axial Stress

Question 46

The weight overlying column of rock.

Answer 46

Lithostatic Pressure

Question 47

The weight of a column of fluid in the interconnected pore spaces ina rock.

Answer 47

Hydrostatic Pressure

Question 48

T or F Fluids at rest can support shear stress.

Answer 48

False, they cannot.

Question 49

Stress Measurement: Forces related to plate tectonics, and stress regimes expected from these forces.

Answer 49

World Stress Maps

Question 50

Stress Measurement: The change in shape reflects the compressive stresses that have been released but also depends on the rock's elasticity. The stress is calculated from the elastic properties of the rock.

Answer 50

Overcoring

Question 51

Stress Measurement: Neotectonic Stress a. Zones of failure in a wall. b. Irregular and typically elongated shape. c. Elongated direction is parallel to minimum horizontal stress. d. Measured using dipmeter or well imaging tools.

Answer 51

Borehole Breakout

Question 52

Stress Measurement: Tectonic Stress

Answer 52

Anderson's Model of Faulting

Question 53

Aluminosilicate polymorph characterized by the prssure and temperature regimes of; T: 400-850 C P: 3.2 - 10 kb

Answer 53

Kyanite

Question 54

Aluminosilicate polymorph characterized by the prssure and temperature regimes of; T: 400-850 C P: 0-3.2 kb

Answer 54

Andalusite

Question 55

Aluminosilicate polymorph characterized by the prssure and temperature regimes of; T: 850-900 C P: 0-10 kb

Answer 55

Sillimanite

Question 56

A mechanism that synchronously forms a subduction zone and a strike-slip fault. The normal stress is accomodated by the subduction/trench system. The shear stress is accomodated by a strike-slip fault.

Answer 56

Shear Partitioning

Question 57

The _____________ __________ is a product of the oblique convergence between the Philippine Sea Plate and the Philippine Mobile Belt.

Answer 57

Philippine Fault