I have a project for a class and our goal is to design a beam using 1018 steel to achieve a certain deflection under one load and not fail under an even larger load. The design I have come up with is very similar to a cantilever beam, but is has a variable cross section. I have used the Euler-Bernoulli beam theory to find the proper dimension to minimize the volume and achieve the goals. I then built my design in ANSYS and my deflection values varied GREATLY. With beam theory I was getting about 3.655 inch deflection, ANSYS was giving me about a .031 inch deflection. That is all under a 60 lbf load Is there a more elaborate beam theory or more correct one that I could use? Attached is a pdf of my work in MathCAD and picture of my ANSYS model if that would help.