Wind engineering pioneer Jon A. Peterka died May 21 in Fort Collins, Colo. Born on May 26, 1941, he was five days shy of his 78th birthday.
“The wind and structural engineering community has lost a giant,” says Donald R. Scott, a vice president of structural engineer PCS Solutions.
Peterka is known for his contributions to and influence on the wind load provisions of the Minimum Design Loads and Associated Criteria for Buildings and Other Structures, called ASCE 7, published by the American Society of Civil Engineers. He chaired the writing of the first wind tunnel testing standard, ASCE 49-12, and was one of the reviewers for the Journal of Wind Engineering and Industrial Aerodynamics. His knowledge and experience in the field will be greatly missed, says Scott.
Pivotal in Commercializing Wind Engineering
In 2014, after his retirement from CPP Wind Engineering Consultants--which he co-founded in 1981 with his former professor Jack Cermak--Peterka mostly served as an expert witness.
With Cermak, Peterka was pivotal in commercializing the professional practice of wind engineering and wind tunnel testing, taking it out of the academic realm and into a business environment, according to CPP. This involved using academic experience to design and build a more capable wind tunnel. It also involved developing the instrumentation and software needed.
“As well as being one of the founders and leaders of CPP, Jon was a globally recognized figurehead, a brilliant engineer and mentor to many of us,” says Roy O. Denoon, a vice president of CPP, which was formerly known as Cermak, Peterka, Petersen. “He was far more globally recognized than I think even he knew.”
The first generation of wind engineers who had exposure to all parts of the field and first-hand knowledge of the reasoning behind much of industry practice is getting much thinner. “With Jon’s passing we have lost the last of the U.S. originals,” says Denoon. Two others are Cermak and the late Alan G. Davenport.
Peterka’s career in wind engineering started in 1964, during his third year as an undergraduate at Colorado State University, when he began working in Cermak’s laboratory. Peterka earned bachelor’s (1964) and master’s (1965) degrees in civil engineering from CSU before attending Brown University for doctoral studies in fluid mechanics and thermodynamics.
After earning his Ph.D. in 1968, Peterka served for three years at the Army Missile Command in Huntsville, Ala. There, according to CPP, the seed was planted for what would later prove to be one of the most notable aspects of his career: forensic engineering.
Series of Detonations
Peterka arrived in Huntsville six months after a series of detonations on the launch pad had puzzled engineers working on the MGM52 Lance missile. By applying numerical techniques by hand, he successfully predicted the detonation behavior to within 0.01 seconds.
From 1971 until 1993, Peterka taught civil engineering at CSU. Working alongside Cermak, Peterka reignited his career in wind engineering.
According to CPP, the first wind load study he supervised took a team of students and professors--working two shifts a day, six days a week--six weeks to gather data. That same exercise can be done in less than an hour today, thanks to computers.
In 1981, the pair co-founded Cermak, Peterka and Associates. It took about two years for the firm to get on its feet, says CPP. From software and analysis procedures to data collection equipment and the wind tunnels themselves, all aspects of the new business were designed and built from scratch.
In 1984, Ron Petersen joined Cermak and Peterka, and the company was renamed Cermak Peterka Petersen.
Shift to Peak Wind Gust
For ASCE 7, Peterka was instrumental in the decision to shift the basis of the wind code from what is known as a fastest mile wind speed to a peak gust wind speed. Designers around the world now use the peak wind gust when they estimate wind loads on buildings and structures.
In 1995, Peterka’s contributions heavily influenced the development of the wind map for regions of the U.S. that are not in hurricane zones. The map greatly simplified how engineers determine design wind speeds for locations around the nation and consequently reduced confusion and improved code compliance, says CPP. The national wind map remains largely unchanged to this day.
Denoon says Peterka was “great at pushing us and making us think outside the box. He will be sadly missed for his insight, guidance, good humor and willingness to enjoy a long lunch on occasion.”