 Welcome back Mechanicaleer. Did you know that the approach to determine deflection of beams appears to have been first developed by Klebs? In 1862, this makes us wonder, what is deflection of a beam? Before we jump in, check the previous part of this series to learn about what impact load is. Now, deflection is a degree to which a structural element is displaced under a load. It may refer to an angle or a distance. The deflection distance of a member under a load is directly related to the slope of the deflected shape or the member under that load and can be calculated by integrating the function that mathematically describes the slope of the member under that load. Macaulay's double integration method is a technique used in structural analysis to determine the deflection of Euler-Bannoulli beams. Use of Macaulay's technique is very convenient for cases of discontinuous and or discrete loading. Typically, partially uniformly distributed loads, UDLs and uniformly varying loads, UVLs over the span and a number of concentrated loads are conveniently handled using this technique. The differential equation is the product of EI and second differential of Y with respect to X equal to moment M. Hence, we first saw what deflection of beams are and then went on to see what Macaulay's method is. So, like, subscribe and comment with your feedback to help us make better videos. Thanks for watching. Also, thanks a lot for those constructive comments. You help the channel grow. So, here are the top mechanical EIs of our last videos. In the next episode of Mechanical EI, find out what cylindrical and spherical shells are.