FRAMES AND MACHINES
Learning Objectives
1). To evaluate the unknown reactions at the supports and the
interaction forces at the connection points of a rigid frame in
equilibrium by solving the equations of static equilibrium of the
overall structure and each individual member.
2). To do an engineering estimate of these quantities.
Definitions
Two-Force Member: a structural member that is loaded only at
two pin joints along the member.
Multi-Force Member: a structural member that is loaded at
more than two points along the member.
Truss: a rigid framework of straight, lightweight two-force
members that are joined together at their ends.
Frame: an assembly of rigid members (of which at least one is a
multi – force member) intended to be a stationary
structure for supporting a load.
Machine: an assembly of rigid members designed to do
mechanical work by transmitting a given set of input
loading forces into another set of output forces.
Newton’s Third Law
Newton’s Third Law: For each action there is an action and
opposite reaction
F F
A A
Body1 Body 2
ej
