Over 100 Years of Design by Advanced Analysis

A Warren Distinguished Lecture 
and Dexter Memorial Lecture
with Ron Ziemian

Civil Engineering
Bucknell University

Abstract

Many engineers in the 1930s considered the new plastic design method unsafe because of a frustrating paradox, and elastic theory continued to prevail despite early experiments by Gábor von Kazinczy and others showing that steel beams and frames can reach their full potential by forming plastic hinges and collapse mechanisms. That paradox was eventually resolved.

In this talk, Ron Ziemian follows John Baker's work to establish plastic design in the UK, its arrival in the United States through the US Navy and Lehigh University, and Lynn Beedle's work to bring it into mainstream steel design. Along the way, Ziemian stops at a school in Norfolk, England, and an apartment building in Binghamton, New York, both of which used plastic design to real advantage. From the 1970s through the 1990s, better computing and second-order inelastic formulations helped move practice from hand-derived mechanisms to incremental-iterative analysis. Despite slow adoption of LRFD in U.S. practice, that work ultimately shaped the AISC provisions for design by inelastic analysis, illustrated through comparisons between plastic-hinge methods and shell-element FEA, along with frame examples and some successful projects. He closes with where advanced analysis is headed and a question to ponder: if computers suddenly ran 1,000 times faster, would we keep considering more load cases or use that power for more sophisticated analyses? Either way, judgment is essential, and a design is only as good as the engineer's grasp of steel behavior and nonlinear analysis.

Speaker

Ron Ziemian is a structural engineer and Professor of Civil Engineering at Bucknell University, with expertise in the analysis and design of steel and aluminum structures. He has authored more than 100 papers, co-authored Matrix Structural Analysis, developed the educational analysis software MASTAN2, and edited the sixth edition of the Guide to Stability Design Criteria for Metal Structures. A registered professional engineer, he serves as a technical consultant to the Aluminum Association and the Rack Manufacturers Institute, and he has held leadership roles on AISC, AISI, and Aluminum Association specification committees, including chairing AISC TC3 – Loads, Analysis and Stability and previously chaired the Structural Stability Research Council. He has delivered keynote lectures at structural engineering conferences around the world and received numerous major honors, including the ASCE Norman Medal, AISC T.R. Higgins Award, SSRC Lynn S. Beedle Award, and AISC Lifetime Achievement Award. At Bucknell, he is recognized for excellence in teaching, having received the Presidential Award for Teaching Excellence and a Presidential Professorship.