# General Bending Theory Explained PTU Notes

0
16
(Last Updated On: February 15, 2016)

If you have have keen interest in the structures than this post ‘General bending theory Explained PTU Notes‘ is going to help u a lot.Basic knowledge of structure starts with understanding of such basic theory.Let us start with this article General bending theory Explained PTU Notes.

## General bending theory Explained:-

### Moment Of Inertia:-

Very basic term of General bending theory Explained PTU Notes article is Moment of inertia. It is the mass property of a rigid body. It is basically the measure of  torque  needed for getting a  angular acceleration about an axis of rotation. It depends on the shape and size of the body.Moment of inertia can be different around different axes. if there is larger moment of inertia around a  axis it means that it requires more torque to increase or stop the rotation  the rotation, of a body about that axis. ## MUST READ:-elements of spacecraft engineering lecture notes for ptu

### General Bending Theory:-

The second basic thing of General bending theory Explained PTU Notes post is general bending theory.The ideal beam is basically a beam  with the least cross-sectional area. Thus it  require the least material. least cross-sectional area is needed to achieve a given section modulus. Since the section modulus depends on the value of the Moment of Inertia.A beam is efficient beam if it  have most of its material located as far from the neutral axis as possible. The more far  a given amount of material is from the neutral axis, the greater  is the section modulus. Hence at last  larger bending moment can be resisted by the member.

When designing beam to resist stresses due to bending the usual starting point is the required section modulus. If the allowable stress is ?max and the maximum expected bending moment is Mmax. , then the required section modulus is given by

S = Maximum bending moment/maximum stress  = I/c

where is I the moment of inertia of the beam cross-section and is c the distance of the top of the beam from the neutral axis