Structural Mechanics: First Moment Of Area And The Moment Of Inertia

Introduction

I am required to obtain some information about the following theories; first moment of area and moment of inertia. The most significant part structural analysis is to get an idea about theories related to structures.

First moment of area

The first moment of area amounts the spreading of an area about an axis. This theory is calculated by summing up the product of each area and its distance from the axis. This is used to check if an area is equally distributed around an axis. I understand that when it comes to structural analysis, symmetric has deep effect. This theory is normally used to determine the centroid of an area where the rotating of an object occurs, the rotation react if the mass reactor. The function of this theory called first moment of area, is to measure the distribution of a beam sections area relative to the axis. According to the information I found, I can conclude by saying that the first moment of area can be used when calculating the value of shear stress at a particular position in the cross section.

The moment of inertia

In the linear beam inertia is basically the resistance to acceleration. So when I apply a force to smaller object, it begin to move but if I apply a force to a larger object it going to be difficult to move. Therefore that bigger object has more inertia. I can conclude by saying mass is straight relative to the inertia. Now when we start to spin things in a circle, we have to take another kind of inertia into account, this the moment of inertia. If I take a maybe a straight wood of two metres and hold it in the middle and try to spin it, it’s pretty easy to spin it. The reason why it is because the distance is equally distributed in to two equal distance. Than if I hold this object at the end it will be hard to rotate it. When I take a circle we the pivot at the middle with a large radius and apply a force to make it rotates, it will rotate at a maximum rotation. But if the radius decreases, therefore the speed of the circle also decreases.

The moment of inertia is a degree of how challenging it is to rotate a specific object about a given axis. The bigger the mass concentrated away from the axis, the greater the second moment of area. second moment of area is applied a lot in structural analysis, such as beams, columns and so on. While the moment of inertia is used in analysis of a rotating object e. g. a wheel.

Conclusion

The first moment of area also with the moment of inertia can be applied in many cases that deals with movements. I can conclude by saying inertia depends on the distance of a certain object. Therefore if there is no distance that means there is no moment of inertia.