CE 201- Statics
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Transcript of CE 201- Statics
CE 201- Statics
Chapter 9 – Lecture 2
COMPOSITE BODIES Composite body consists of simpler bodies
connected together (triangle, rectangle, ….) Composite body can be sectioned into its composite
parts Center of gravity of the composite body can be
determined without integration, if weight and center of gravity of each part is known
Each part can be treated a discrete particle and use:x = ( x W) / WR
y = ( y W) / WR
z = ( z W) / WR
COMPOSITE BODIES When the body has a constant density or specific weight, the center of
gravity coincides with the centroid of the body The centroid of line, area, and volume can be found by replacing W
with L, A, and V (respectively) in the equations above:x = ( x L) / Ly = ( y L) / Lz = ( z L) / L
x = ( x A) / Ay = ( y A) / Az = ( z A) / A
x = ( x V) / Vy = ( y V) / Vz = ( z V) / V
Procedure for Analysis
Divide composite body into simpler shapes If the body has a hole or geometric region having
no weight, then consider the body without the hole and the hole as an additional composite part having negative weight or size.
Determine x, y, and z of the center of gravity or centroid of each part
Determine x, y, and z of the whole body