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9.5:

Centroid for the Paraboloid of Revolution

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Mechanical Engineering
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JoVE Core Mechanical Engineering
Centroid for the Paraboloid of Revolution

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A paraboloid of revolution is an axially symmetric surface generated by rotating a parabola around its axis. This shape has several applications in engineering, such as for designing submarines that have reduced drag, self-supporting domes that do not need extra support, and dish antennas that focus electromagnetic waves toward the receiver at its focal point. For calculating an object's weight-bearing capacity and stress absorption, knowing the centroid is crucial and helps engineers design more robust support systems. Consider an appropriate coordinate system for locating the centroid of the paraboloid of revolution. A differential element in the shape of a thin disk is chosen that intersects the generating curve at an arbitrary point and defines its radius in terms of the given coordinate. The volume and moment arm are calculated for the differential element. These values are then substituted into the centroid equation. Finally, the limits are set up from two extreme locations, and the integration is solved to obtain the location of the centroid.

9.5:

Centroid for the Paraboloid of Revolution

The paraboloid of revolution is an axially symmetric surface generated by rotating a parabola around its axis. This shape has several applications in mechanical engineering due to its advantageous structural properties, such as strength against stress concentration points and rotational symmetry.

The centroid for the paraboloid of revolution is the point where all the mass of the paraboloid is concentrated. This centroid is important for engineering applications, as it determines how forces are distributed across a surface. Knowing this centroid can also help when constructing equipment that needs to be reliable under stress and pressure.

One major application of the paraboloid is in satellite dish antennas. The shape of a paraboloid can be used to reflect and focus electromagnetic waves to a single point. Another application of the paraboloid in optics is to create parabolic mirrors, lenses, and reflectors, where the exact focusing of light waves is necessary. The paraboloid is also used in architecture for creating domes and pavilions. This shape can create a self-supporting structure that requires no additional support. The paraboloid shape is also used extensively in civil engineering for constructing water tanks and storage vessels.

It is also worth noting that the centroid for a paraboloid of revolution does not always have to be located at the center of the surface. In some cases, the centroid can be offset from the center point due to various factors, such as the size and shape of the paraboloid. This means that engineers should always be aware of the location of the centroid before building any equipment that requires a paraboloid shape.

Suggested Reading

  1. Hibbeler, R.C. (2016). Engineering Mechanics: Statics. Fourteenth Edition, New Jersey: Pearson. Section 9.1, Pp. 477.