Influence Lines and Moving Loads - Intro to Structural Analysis

This video defines the concept of an influence line for a moving loads across a structure. This is a very useful technique in bridge engineering.

If you want to follow along with the statics (which are skipped in interest of brevity), the full calculations can be downloaded here:
https://drive.google.com/file/d/19rEG...

An influence line plots a specific action (for example, a reaction force or the shear or moment at a specific point) for a unit load at position x, moving along the structure. These can be used to find the extreme loading events for a specific demand.

This video covers how to solve for an influence line using statics. The Muller-Breslau principle, which can be used to find influence lines using geometry, is described here:    • Muller-Breslau Principle for Influenc...  

What can you do with influence lines? Check out this video on how to use influence lines to position live load and get the worst case demands (i.e., to find the design envelopes):    • Design Envelopes for Worst-Case Deman...