The author is a Professor Emeritus at the Norwegian University of Science and Technology (NTNU). His major field of interest is continuum mechanics.
He obtained an M.Sc. degree in Theoretical and Applied Mechanics from Iowa State University in 1960, and completed a degree in Civil Engineering, majoring in Structural Engineering at NTNU in (1960) He started his academic carrier as an Assistant and Associate Professor in Mechanics at NTNU in 1963 and was appointed Professor in Solid Mechanics at NTNU in 2003. He has been a Visiting Professor at the University of Connecticut and University of Colorado.
He has been involved in a variety of projects in which fluids and fluid-like materials have been modeled as non-Newtonian fluids, such as avalanching snow, granular materials in landslides, extrusion of aluminium, modeling of biomaterials as bone, and viscoplastic modeling of paper to simulate the calendaring process. He is author or coauthor of 26 papers and 11 conference presentations on mechanics and biomechanics.
He has published the following textbooks in the Norwegian language: Statics, 7 editions; Strength of Materials, 7 editions; Dynamics, 4 editions; Continuum Mechanics; and Tensor Analysis. In 2008 his book Continuum Mechanics was published by Springer Verlag. In 2014 his book Rheology and Non-Newtonian Fluids was published by Springer Verlag.
At NTNU he has lectured on elementary and advanced topics in the entire field of theoretical and applied mechanics: engineering mechanic, dynamics, fluid mechanics, biomechanics, rheology, continuum mechanics and tensor analysis. For NTNU he has developed new courses in Continuum Mechanics, Tensor Analysis, Rheology and Non-Newtonian Fluids, and Biomechanics.