Webinar: Pier Cap Design Utilizing the Strut-and-Tie Provisions of AASHTO LRFD and MIDAS Civil Software

In this Midas Webinar Session, our Top Expert Engineer Daniel Baxter and Shayla Olson from Michael Baker International shared their knowledge present on pier cap designs using the strut-and-tie method and explain how to use the moving load tracer function in MIDAS and how to write nodal load definitions to the MCT program text file.

Expert Tip: Suspension Bridge Analysis Using Trigonometric Methods

There are a couple of ways to analyze suspension bridges. As previously discussed (Uniqueness and Difficulties of Suspension Bridge Analysis), the deflection theory proposed by Melan and solved by Moisseiff is one of the first. The second one may be trigonometric methods proposed by Timoshenko (Theory of suspension bridges, Journal of the Franklin Institute, Volume 235, Issue 4, April 1943, Pages 327-349). In this article, a brief explanation of trigonometric methods and related excel, and the example bridge dimensions will be provided.

Expert Tip: Why Not Solving Dynamic Problems Using Excel?

What is the Equilibrium Equation for Dynamic Problems?  The equilibrium equation for any dynamic problem can be expressed as Eq (1). Eq (1) is just an extension of a more familiar equilibrium equation for a static problem. Figure 1. Representation of a simple static spring system.  In Eq (2), F is the applied force, k is the stiffness, and y is the displacement. We know F and K, so we can calculate y. In other words, we have only one unknown y, so we can calculate y. In Eq (1), F(t) is the applied force, k is the stiffness, and y(t) is the displacement just like in Eq (2). y(t) varies along time t because applied load F(t) varies along time t.