A device developed by engineers at Southwest Research Institute (SwRI) in 1962 that characterizes the dynamic response of materials at high strain rates has been designated a historic mechanical engineering landmark by the American Society of Mechanical Engineers. ASME conferred the honor on the split Hopkinson pressure bar (SHPB) apparatus at a ceremony held Dec. 1 at SwRI, a nonprofit research and development organization based in San Antonio. The honor places the SHPB among 240 other mechanical engineering achievements throughout the world distinguished for their contribution to technological progress and public service. “This designation is a great honor for Southwest Research Institute,” said SwRI President J. Dan Bates. “For nearly 60 years, our staff has developed technology of great significance for both industry and government, and the split Hopkinson pressure bar stands among those achievements.” The design or performance assessment of a component or structure requires accurate knowledge of the elastic and inelastic strength properties of the materials involved. These properties may vary with both temperature and time. The SwRI split Hopkinson pressure bar was developed to characterize materials at high strain rates in the range of 102 s-1 to 5.0 x 103 s-1, typical of many scenarios involving explosives, ballistic impact and crashes of interest for both military and civilian applications. The apparatus, based on devices invented by Bertram Hopkinson and Herbert Kolsky, was developed in 1962 by Ulric Lindholm, who retired from SwRI in 1994. Notable applications include determining the dynamic strength of steel in North Sea offshore platforms subjected to impact, defining the compressive strength of ceramics used in advanced armors, evaluating pipeline and nuclear pressure vessel steels and evaluating the strength of materials on the pressurized hulls of the International Space Station under impact from meteorites or other orbital debris impact. The mechanical engineering landmarks program is administered by the History and Heritage Committee of ASME International. This is the second such honor for Southwest Research Institute. The Southern Gas Association Analog, developed by SwRI in 1955 for the natural gas industry, was named an ASME mechanical engineering landmark in 1990. Other ASME landmarks include the Saturn rocket, Voyager space probes and Edison phonograph. For more information, visit: www.swri.org/