Force, Stress, and Strength [start reading Chapter 3]

GLG310 Structural Geology

Force, Stress, and Strength[start reading Chapter 3]

April 20, 2023 GLG310 Structural Geology

• Introduction

• Dynamic analysis

• Force

• Tractions

• Stress

• Relationships between stress and strain

• Deformation experiments

Structural Geology

• Introduces the physical side of Geological Sciences and emphasizes – Geometry (shape, orientation, position, size,

etc.)– Motion (beginning and ending positions and

paths of particles and bodies—deformation or change in geometry)

– Mechanics (explanations of why the geometry and motion are how they are)

04/20/23 GLG310 Structural Geology

http://gdavis.web.arizona.edu/node/105

Geometric and kinematic description

http://gdavis.web.arizona.edu/node/105

4 September 2012 GLG310 Structural Geology

Structural Analysis

• Descriptive Analysis– Recognize and describe structures and measure

their locations, geometries and orientations • Scale, Structural Elements

• Kinematic Analysis– Focus on motion of materials

• Dynamic Analysis– Interpret motions in terms of applied forces

Physical Models


Simulate earth processes in a controlled experimentBuild intuition versus actual predictionIdentify controlling processes or conditions

http://www.youtube.com/watch?v=A5hC47RGq0Y

http://www.youtube.com/watch?v=A5hC47RGq0Y


http://www.youtube.com/watch?v=xDQRfNEBR2w

Mechanics

• Develop simple rules to explain behavior

• Can be stated in symbolic or mathematical terms



Isaac Newton

Sir Isaac Newton was an English physicist, mathematician, astronomer, natural philosopher, alchemist and theologian, who has been "considered by many to be the greatest and most influential scientist who ever lived.”

Philosophiæ Naturalis Principia Mathematica, often referred to as simply the Principia, is a work in three books by Sir Isaac Newton, first published 5 July 1687

F=mA

April 20, 2023

Force: Newton’s Laws of Motion

• Law I: Every body continues in its state of rest, or in uniform motion in a straight line, unless it is compelled to change its state by forces impressed upon it.


http://www.poolplayers.com/instruction/terry-bell/2011/04/billiards-master-class-9-approach-and-procedure/ 1:25 cue ball to pool ball force transfer

April 20, 2023


• Law II: The rate of change of momentum is proportional to the impressed force and is made in the direction in which the force is impressed.



April 20, 2023


Dimensional analysis: fundamental units

Mass = amount of material in a bodyWeight = Force due to gravity action on a body1 liter of water has a mass of

on earth it weighson the moon it weighs



What does a Newton feel like?

http://www.youtube.com/watch?v=LOINRpWGrlw

April 20, 2023

What does a Newton feel like?

-Davis and Reynolds (vo. 2), p. 101


Force: Forces as vectors

use the tip-to-tail method to find the resultant force

http://www.hk-phy.org/contextual/

http://www.hk-phy.org/contextual/mechanics/for/add_force/resultant_force_e.html

Block mass is 10000 kgWhat is normal and shear force along base?Dip is 10 degrees.



• Law III: To every action there is always opposed an equal reaction, or the mutual actions of two bodies on each other are always equal in magnitude and opposite in direction http://www.hk-phy.org/contextual/


• Law III: To every action there is always opposed an equal reaction, or the mutual actions of two bodies on each other are always equal in magnitude and opposite in direction

Equilibrium


Driving and resisting forces of plate tectonics

Documents

Force, Stress, and Strength [start reading Chapter 3]