Why bending moment is important

Try our Mobile App. How to Determine the Reactions at the Supports? How to Calculate an Indeterminate Beam? Truss Tutorials What is a Truss? Bending Moment Definition In this tutorial, we will simply answer the question: what is a bending moment? Bending Moment Example To calculate the bending moment about a reference point, we take the magnitude of the force and multiply it by the distance of the force from the point.

Though that sounds confusing, it can be simplified in our example: In the above example, the bending moment at point A is simply the distance multiplied by the force. Was this article helpful to you? Yes No. How can we help?

Free Account Today! Try SkyCiv Mobile! While designing the cantilever shaft or any type of beam and shafts for that matter we normally go ahead drawing the bending moment diagram to find the maximum bending moment value than creating the shear force diagram.

Most of the time we ignore the maximum shear stress value for the shaft for the purpose of the shaft design calculation. Why we care or scare more for the maximum bending stress than the maximum shear stress value?

Maximum bending stress equation for beams with rectangular cross section:. Maximum shear stress equation for beams with rectangular cross section:. Y — Distance of the Area of interest from the neutral axis. I — Area moment of inertial of the area of interest. Now, from the Eq. And, from the Eq. This tries to bend the beam in the plane of the member, and due to transmission of it over a cross-section of the beam, the Developed Bending stress distribution is Linear from the neutral axis of the beam.

Shear Force Diagram is the Graphical representation of the variation of Shear Force Over the cross-section along the length of the beam. With the B. While constructing the Shear Force Diagram [S.

Fixed Support: It can offer three reactions in the plane of the member 1 Horizontal reaction, 1 Vertical reaction, 1 Moment reaction. Pin Support: It can offer two reactions in the plane of the member 1 Horizontal reaction, 1 Vertical reaction. Roller Support: It can offer only one reaction in the plane of the member 1 Vertical reaction. Concentrated or point Load: In this, the entire intensity of load is restricted to a finite area or on a point.

Uniformly Distributed Load [U. Uniformly varying Load [U. Consider the simply supported beam shown in the figure below carrying Point loads only. In a Simply supported beam, one end is pin supported while another end is roller support. The value of the reaction at A and B can be calculated by applying Equilibrium conditions of. Putting the value of R B in [1], we get. According to the Sign convention discussed earlier, if we start calculating Shear Force from the Left side or Left end of the beam, Upward acting force is taken as Positive, and Downward acting Force is taken as Negative.