Examples On Determining Centroids Of Areas

EXAMPLES ON DETERMINING CENTROIDS OF AREAS

1. Find the centroid of the following built-up section

From the AISC ( American Institute of Stee Cosntruction ) Construction Manual

Area of WF18x71 = 20.8 in2

Area of C10x30 = 8.82 in2

From Symmetry

2. Determine the location of the centroid of the following shape:

1. Assume the shape to be made of two areas. The (Positive) 10”x10” square and (Negative) 3”x3” square ( negative since it is cut from the original shape).

2. The distance of the centroid of the small square from the X and Y axes is shown in the figure.

3. The centroid of the larger square is 5” from either axis. While the centroid of the small square is as shown

3. Find the location of the centroid of the following channel. The thickness of the channel is 0.5” all around.

1. The channel has a horizontal axis of symmetry. Therefore the centroid has to lie on this axis.

2. To find the location of the centroid. Divide the channel into three areas as shown.