Dr. Johnson specializes in solid mechanics, biomechanics, and finite element analysis (FEA). He has extensive experience in the development of novel constitutive models for finite element analysis of biological materials, as well as the translation of medical image data into finite element meshes. As a Research Assistant at the Massachusetts Institute of Technology (MIT), he applied his expertise in these fields to experimental and numerical characterization of the pre-failure, rate-dependent properties of both cortical and trabecular bone. He also has significant experience in various low impedance split-Hopkinson (Kolsky) pressure bar techniques and has employed them in the high strain rate characterization of both biological and polymeric materials.
Prior to joining Exponent, Dr. Johnson worked as a consultant in the investment banking industry where he developed automated trading algorithms to capitalize on arbitrage opportunities within the foreign exchange spot market. In addition, Dr. Johnson has worked as a technical consultant for an international manufacturing firm, where he provided product performance reviews and researched expansion opportunities for the company into the US marketplace.
Johnson TPM, Socrate S, Boyce MC. A viscoelastic, viscoplastic model of cortical bone valid at low and high strain rates. Acta Biomaterialia 2010; 6(10):4073–4080. DOI: 10.1016/J.ACTBIO.2010.04.017.
Johnson TPM, Sarva SS, Socrate S. Comparison of low impedance split-Hopkinson pressure bar techniques in the characterization of polyurea. Experimental Mechanics 2009; 50(7):931–940. DOI: 10.1007/S11340-009-9305-Y.
Presentations
Johnson TPM, Socrate S, Boyce MC. Micromechanics of the rate dependent elastic-plastic behavior of trabecular bone. Proceedings, 16th US National Congress of Theoretical and Applied Mechanics, State College, PA, 2010.
Johnson TPM, Socrate S, Boyce MC. A viscoelastic, viscoplastic model of cortical bone. Proceedings, SEM Annual Conference and Exposition of Experimental and Applied Mechanics, Albuquerque, NM, 2009.
Johnson TPM, Sarva SS, Socrate S. A comparative study of low impedance split-Hopkinson pressure bar techniques. Proceedings, SEM XI International Congress and Exposition of Experimental and Applied Mechanics, Orlando, FL, 2008.