Aisc connections teaching toolkit

Connections Teaching Toolkit

Perry S. Green, Ph.D. Thomas Sputo, Ph.D., P.E. Patrick Veltri

A Teaching Guide for Structural Steel Connections

PREFACE

This connection design tool kit for students is based on the original steel sculpture designed by Duane S. Ellifritt, P.E., Ph.D., Professor Emeritus of Civil Engineering at the University of Florida. The tool kit includes this teachingguide, a 3D CAD file of the steel sculpture, and a shear connection calculator tool. The teaching guide contains drawings and photographs of each connection depicted on the steel sculpture, the CAD file is a 3D AutoCAD® model of the steel sculpture with complete dimensions and details, and the calculator tool is a series of MathCAD® worksheets that enables the user to perform a comprehensivecheck of all required limit states. The tool kit is intended as a supplement to, not a replacement for, the information and data presented in the American Institute of Steel Construction’s Manual of Steel Construction, Load & Resistance Factor Design, Third Edition, hereafter, referred to as the AISC Manual. The goal of the tool kit is to assist students and educators in both learning and teachingbasic structural steel connection design by visualization tools and software application. All information and data presented in any and all parts of the teaching tool kit are for educational purposes only. Although the steel sculpture depicts numerous connections, it is by no means all-inclusive. There are many ways to connect structural steel members together. In teaching engineering students in anintroductory course in steel design, often the topic of connections is put off until the end of the course if covered at all. Then with the crush of all the other pressures leading up to the end of the semester, even these few weeks get squeezed until connections are lucky to be addressed for two or three lectures. One reason for slighting connections in beginning steel design, other than timeconstraints, is that they are sometimes viewed as a “detailing problem” best left to the fabricator. Or, the mistaken view is taken that connections get standardized, especially shear connections, so there is little creativity needed in their design and engineers view it as a poor use of their time. The AISC Manual has tables and detailing information on many standard types of connections, so theprocess is simplified to selecting a tabulated connection that will carry the design load. Many times, the engineer will simply indicate the load to be transmitted on the design drawings and the fabricator will select an appropriate connection. Yet connections are the glue that holds the structure together and, standardized and routine as many of them may seem, it is very important for a structuralengineer to understand their behavior and design. Historically, most major structural failures have been due to some kind of connection

failure. Connections are always designed as planar, twodimensional elements, even though they have definite threedimensional behavior. Students who have never been around construction sites to see steel being erected have a difficult time visualizing thisthree-dimensional character. Try explaining to a student the behavior of a shop-welded, field-bolted double-angle shear connection, where the outstanding legs are made purposely to flex under load and approximate a true pinned connection. Textbooks generally show orthogonal views of such connections, but still many students have trouble in “seeing” the real connection. In the summer of 1985, afterseeing the inability of many students to visualize even simple connections, Dr. Ellifritt began to search for a way to make connections more real for them. Field trips were one alternative, but the availability of these is intermittent and with all the problems of liability, some construction managers are not too anxious to have a group of students around the jobsite. Thought was given to building...