Moment of force

University of Babylon
College of Engineering
Department of Architectural Engineering
Lectures of
Structure I
? Instructor: Dr. Majid Mohammed Ali
? E-mail :eng.majid.mohammed@uobabylon.edu.iq
? 2 hours per week
? Conduct
Quizzes, homework and project Mid-term exam Final exam
10% 30% 60%

? Content of the term
General introduction about forces, their kinds and affects 1 week
Resultant of forces 3 weeks
The couple 1 week
Equilibrium 4 weeks
Analysis of truss 3 weeks
Drawings of axial, shear forces ,and bending moments 3 weeks


? References:
Higdon, and W. Stiles ," Engineering Mechanics", 3rd edition, prentice Hall of India, New Delhi ,1974
Hibbeler," Engineering Mechanics-Static", 12rd edition, Mc Grew Hill ,2008
Meriam, J. L., Kraige, L. G. " Engineering Mechanics-Static", 2008

Moment of force
It is ability of a force to turning or twisting a body about any axis.
Magnitude of moment

Where: d is the perpendicular distance from the axis of moment to the line of acting of the force.
Units
The basic units of moment according to SI units are newton-meters N.m, kN.m, N.mm…etc
Sign convention
According to the right hand rule
Couple
The couple can be defined as two forces which have equal magnitude and parallel lines of action but they should be opposite in direction.
Magnitude

Units
The basic units of couple according to SI units are newton-meters N.m, kN.m, N.mm…etc
Determine the coordinates of the point on the x and y axes about which the moment of F is zero?