what is the second moment of area and its uses?

Question

i want to know about second moment of area

Answer 1

how technical do you want to be?
in breif the second moment of area is a property that indicates how well a cross sectional shape will resist bending. for example a steel rod will be easier to bend than a steel pipe, even if they have the same cross-sectional area.

It turns out that the further away the mass of the beam is from center, the better it resists bending. This is why the common steel piece used in construction is an I beam. the center of the i holds the top and bottom apart. the top and bottom 'wings' carry the majority of the load.

to use it for example imagine a rectangular beam is used as a bridge across a stream and a person steps out onto it. the stress at point in the beam is a function of the moment (bending load) and is opposed by the second moment of area. so the larger the second moment the less stress, and the beam is less likely to break.

You can find formulas for different shapes on the internet.

Answer 2

Second moment of area From Wikipedia, the free encyclopedia This article is about the moment of inertia as related to the bending of a plane. For the moment of inertia dealing with rotation of an object, see Moment of inertia. The second moment of area, also known as the area moment of inertia and less precisely as the moment of inertia, is a property of a shape that is used to predict its resistance to bending and deflection. It is analogous to the polar moment of inertia, which characterizes an object's ability to resist torsion. The second moment of area is not the same thing as the moment of inertia, which is used to calculate angular acceleration. Many engineers refer to the second moment of area as the moment of inertia and use the same symbol I for both, which may be confusing. Which inertia is meant (accelerational or bending) is usually clear from the context and obvious from the units. See also moment (physics).