Lecture 19 Stresses (1)
Lecture 19 Stresses (1)
F orce Force is a kind of mechanical action between different objects it tends to change the shape, volume or movement state of the object with a force upon it Force is a vector quantity, and thus possesses both magnitude and direction; it can be represented by an arrow whose length specifies the magnitude and whose orientation specifies the orientation of the force Force mass X acceleration (kg m s-2)INewtonIINI Unit. Newton Newton=I kilogram meter per second squared scalar (on ly magnitude vector
Force Force is a kind of mechanical action between different objects, it tends to change the shape, volume or movement state of the object with a force upon it. Force = mass × acceleration (kg m s-2 ) [Newton][N] Force is a vector quantity, and thus possesses both magnitude and direction; it can be represented by an arrow whose length specifies the magnitude and whose orientation specifies the orientation of the force. F Unit: Newton 1 Newton = 1 kilogram meter per second squared vector scalar (only magnitude)
F A B Resolution and resultant of forces A Force F resolved into two components F, and F B Two forces F and F2 represented by resultant F
Resolution and resultant of forces A Force F resolved into two components F1 and F2 . B Two forces F1 and F2 represented by resultant F F1 F2 F F1 F2 F A B
Surface forces and body forces Surface forces: the forces acting on the contact surface between adjacent parts of rock system, between adjacent blocks or adjacent lithosphere plates. The contact surface may be or may be not a visible material boundary It can be a imaginary surface inside the object considered
Surface Forces and Body Forces Surface forces: the forces acting on the contact surface between adjacent parts of rock system, between adjacent blocks or adjacent lithosphere plates. The contact surface may be or may be not a visible material boundary. It can be a imaginary surface inside the object considered
Body forces Body forces: the forces can work at a distance and depend on the amount of material affected, so, we can call body forces distant forces. Gravitational force is an example of body forces. The gravitational force on a rock body of mass m is F=m where g is the acceleration of gravity. g varies with depth in the earth and with position on the earths surface, but for the purpose of structural geology, it is a constant 9.8m/sec2
Body forces: the forces can work at a distance and depend on the amount of material affected, so, we can call body forces distant forces. Gravitational force is an example of body forces. The gravitational force on a rock body of mass m is F = mg where g is the acceleration of gravity. g varies with depth in the earth and with position on the earth’s surface, but for the purpose of structural geology, it is a constant 9.8m/sec2 . Body forces