Introduction Into Engineering Mechanics II

University of Babylon
College of Engineering
Department of Environmental Engineering
Engineering Analysis I (ENAN 103)







Engineering Mechanics II

Undergraduate Level, 1st Stage



Mr. Waleed Ali Tameemi
College of Engineering/ Babylon University
M.Sc. Civil Engineering/ the University of Kansas/ USA



2016-2017

– Introduction
Force Types
Concentrated force/point load.


Distributed force.


Force Sign Convention











Moments and Couples Sign Convention
Positive sign (+ve), if the couple is rotating counter clockwise.






Negative sign (-ve), if the couple is rotating clockwise.





?
Equilibrium
the external forces equal to the internal forces
??F_x =0
??F_y =0
??M_z =0 at any point
Free-Body Diagram
Type Force Representation Case F.B.D
Body with weight (w) A vertical force equal to the body weight pass through the center of gravity


Roller – Wheel A reaction normal to the surface that the roller move on


Hinge Two perpendicular reactions, one is
normal to the surface and the other parallel to it



Pin
Two perpendicular reactions



Fixed Two perpendicular reactions and a moment


Cord – Cable - Rope Can be replaced by a force along the cable



Smooth Surface A reaction normal to the surface that the roller moves on



Rough Surface Two reactions (normal and parallel) to the surface that the roller move on