Merkle accepted an award of merit, along with the accompanying title of Fellow of the Society, at ASTM's National Symposium on Fatigue and Fracture Mechanics in Williamsburg, Va.
Merkle, an ASTM member since 1971, was honored for his work in developing fracture and fatigue mechanical standards for massive steel pressure vessels that contain the heat-generating reactors and their coolants in nuclear power plants.
ASTM is a not-for-profit organization that provides a forum for producers, users, consumers, government and academia to meet on common ground and write standards for materials, products, systems and services. The committee that Merkle serves on is concerned with developing standards for ensuring that structural materials have the ability to resist fracture even in the presence of flaws. The standards developed by his committee are used by the Nuclear Regulatory Commission (NRC) to ensure that reactor vessels can withstand maximum predetermined levels of water heat and pressure without rupturing.
Merkle's engineering specialty, fatigue and fracture mechanics, concerns the progressive development of damage and weakness in materials due to flaws and cyclic loading. A common example of fatigue occurs when one tries to destroy a credit card by simply bending it back and forth.
Instead of the plastic breaking the first time it is bent, the card will usually withstand many bends until the material eventually becomes so fatigued that it breaks. Using fatigue and fracture mechanics, engineers can apply the same principles demonstrated by the credit card to characterize breaking points of large structures and vessels.
Merkle earned both bachelor's and master's degrees in civil engineering from Cornell University in 1957 and 1962, respectively. He was an officer in the Civil Engineering Corps of the U.S. Navy from 1957 to 1960 and joined ORNL as a civil engineering designer in 1962. Now a senior research specialist in the Engineering Technology Division at ORNL, Merkle has been involved with ORNL's Heavy Section Steel Technology Program since its inception in 1967. He has been involved with developing and implementing standards for nuclear reactor vessels at Turkey Point in Florida, Zion in Chicago and Nine Mile Point in New York.
Merkle is a native of Darien, Conn. He and his wife, Marilyn, have four grown children. They live in Knoxville, where Merkle has been active with Boy Scout troop 350.
ORNL, one of DOE's multiprogram national research and development facilities, is managed by Lockheed Martin Energy Research Corp.