COE2001 Exam 1 Terms - Equilibrium

what are the equations of 2D equilibrium for concurrent systems?

sum of Fx = 0 and sum of Fy = 0

what are the equations of 2D equilibrium for non-concurrent systems?

sum of Fx = 0, sum of Fy = 0, and M_any pt = 0

Newton’s First Law

An object remains at rest if there is no unbalanced force acting on it.

The four required items for a free-body diagram

body is isolated from surroundings, coordinate axis system, reactions and applied forces, and dimensions and labels

the five steps to solving an equilibrium problem?

FBD, classify system, determine unknowns, apply equilibrium

What is a centroid?

geometric center of a line, an area, or some volume

List the characteristics of a centroid:

same as center of mass for homogenous material, not necessarily on the shape, always located on axis (axes) of symmetry (if they exist)

What type of support condition is this?

Roller

Roller support condition prevents forces in what direction?

y-direction

What type of support condition is this?

Pin

Pin support condition prevents forces in what direction(s)?

x- and y- directions

What type of support condition is this?

Fixed

Fixed support condition prevents forces in what direction(s)?

x-, y-, and z-directions

What type of support condition is this?

Cable

Cable support condition prevents forces in what direction(s)?

parallel directions

What support condition does this represent?

Frictionless Slot

Frictionless slots support prevents forces in what direction?

y-direction

Two-Force Members

member with forces applied only at the ends

Characteristics of two-force members:

neglect self-weight, no applied moments or couples, frictionless pins at ends

What attributes do two-force members have?

equal, opposite, and collinear