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Dusan Krajcinovic: A biographical sketch
International Journal of Plasticity 23 (2007) 1637–1640 www.elsevier.com/locate/ijplas
Guest Editorial
Dusan Krajcinovic: A biographical sketch
Dusan was awarded a B.Sc. (Golden Index as first in class) and a M.Sc. in Civil Engineering from University of Belgrade in 1958 and 1966 respectively. Dusan afterwards, he moved to USA to pursue his Ph.D. in Civil Engineering at Northwestern University, in Evanston, Illinois, which was completed in 1968 under the guidance of Professor George Hermann. He then began a brilliant and successful career in the characterization of material behavior, and the analysis and design of structures. He worked at Ingersoll Rand Research Inc. in 1969 and following that he moved to Argonne National Laboratory in the Theoretical and Applied Mechanics Group. In 1973, he left Argonne to go back to academia, although he would still be a staff member there until 1979. From 1973 to 1989 he was Professor of Civil Engineering at University of Illinois, Chicago, Illinois. He then moved to Arizona State University (ASU), Tempe, Arizona, in the Mechanical and Aerospace Engineering Department, where he stayed until he retired. Dusan has been a Professor Emeritus at ASU since 2004. During his long and fruitful career he gained the admiration of his peers. He was always invited and a main contributor to numerous National and International workshops, 0749-6419/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.ijplas.2007.03.002
1638
Guest Editorial / International Journal of Plasticity 23 (2007) 1637–1640
scientific meetings, symposia, conferences, etc. To name a few of these scientific gatherings were the 1989 NATO Advanced Study Institute on Disorder and Fracture (J.C. Charmet, C. Roux and E. Guyon), and the 1992 Institute of Theoretical Physics at the University of California, Santa Barbara (J. Langer and J.R. Rice). His career is multifaceted and reflects Dusan’s personality, ability and versatility. His record of professional and academic achievements is vast and impressive. As a professional engineer he was involved in the design of major concrete structures. A notable example is the 90 m high concrete arch dam in Glazanj, where he was in charge of the structural analysis. He was an active consultant also in the areas of fracture and damage mechanics. The list of consulting companies and institutions that he worked for is long and encompasses prestigious international names, such as Energoprojekt, Argonne National Laboratory, the US Department of Interior (member of a panel of USA experts in the USA–USSR U-25 test series in Moscow), Procedyne Corp., Conselho de Gestao, Gabinete da Area de Sines (Portugal), Sargent and Lundy Engineers, The World Bank, Lufthans, Enrico Fermi National Accelerator Laboratory, Paslode Co.,The University of Michigan, Wiss, Janney, Elstner Associates Inc., Sandia National Laboratories, Allied Signal, Arizona Power, Ad Tech, and SelectTech Services Corporation. Technical contributions, such as ‘‘Structural Failures, Attorney’s Guide to Engineering (with P. Popovic)’’ or ‘‘Selected Topics in Dynamic Stability (with R. Plaut, G. Simitses and S.S. Chen)’’, Ch. 19 in ‘‘Guide to Stability Design Criteria for Metal Structures’’ clearly demonstrate his attention towards the industry and non-academic community. In this specially dedicated volume, however, we wish to honor the memory of the academician for his scientific merit and dedication. His research has had a profound impact on the development of damage mechanics of brittle materials. His opinion has been extremely influential and highly regarded in the scientific community. Dusan has been a prolific researcher and co-authored over 200 publications, including refereed journals, proceedings, contributed chapters, co-edited books and his own book on damage mechanics. His is a well known authority in the field of damage mechanics. He has been for many years organizer of a number of short courses and symposia in damage mechanics worldwide. Dusan has received a number of awards, such as the October Prize for Mathematical, Physical and Engineering Science (Belgrade, Yugoslavia 1990), the Gold Medal for achievements in Science and Technology (Crete 1999) and Laurea Honoris Causa (Milan Italy, 2001). He was a member of many editorial boards of scientific journals, e.g. Applied Mechanics Reviews and Mechanics of Materials, and still is one of the chief editors of the International Journal of Damage Mechanics. Dusan was constantly involved with professional societies, such as ASME (fellow and president of AMD executive committee 2001–2002), American Academy of Mechanics (fellow and president 1999–2001), Stability Research Council, International Association for Structural Engineering in Reactor Technology and ASCE (non-member advisor of the Committee for Inelastic Behavior of Materials). Within the ASME he was also a Medal Committee member for the Timoshenko, Koiter, and Drucker Medals and organized international conferences such as MECMAT 03 in Scottsdale, AZ. We briefly review some landmark publications to depict a chronological outline of Dusan’s body of work. The first publications trace back to Dusan’s collaboration with Professor N. Hajdin between 1962 and 1965 when still in Belgrade. The first journal paper on thin-walled structures (Int. J. Sol. Struct. 1969) was published soon after his doctorate. In the best structural engineering tradition, thin walls structures, beams, shells and plates
Guest Editorial / International Journal of Plasticity 23 (2007) 1637–1640
1639
theory was to be the core of his research for another decade. Dusan analyzed problems related to dynamic response, stability and vibrations of these structures, often in combination with plasticity. His papers on dynamic response of circular rigid-plastic plates and beams (1975) are representative examples of that period. In a time when novel computer methods were coming to the fore, Dusan was a strong supporter of the computer revolution and promoter of structural matrix methods, as one can appreciate from his papers from the 70s. During that period, a few of his papers on nuclear technology also appeared, such as ‘‘Fluid–Solid Interaction of Reactor Components: A Preliminary Analysis’’ (with J. Carey 1974). Probably inspired by Budianski and O’Connel’s work (1976), Dusan published ‘‘Distributed Damage Theory of Beams in Pure Bending’’ in 1979, which marks a smooth transition into a brand new field of investigation. He was amongst the first scientists to research in damage mechanics and, from that moment, he would dedicate himself almost entirely to it (setting aside few occasional papers on plasticity). In 1981, he published ‘‘The Continuous Damage Theory of Brittle Materials, Part I & II: Uniaxial and Plane Response Modes’’ (with G.U. Fonseka), where a family of vectors is used to represent microscale damage in an elastic brittle solid, typically concrete. The theory offered a simple approach to treat unilateral conditions and to rationally derive a damage measure based on the microstructure but independently of the applied load. Limitations of this simple approach under complex strain states were pointed out, for example, by Chaboche. Hovewer, this often cited work contributed to highlighting the controversial mathematical nature of the damage variable. Damage models based on fracture mechanics and micromechanics would be distinctive of Dusan’s work in the 80s. In 1982, Dusan explored the relation between strength theory and damage and published the work on ‘‘Statistical Aspects of the Continuous Damage Theory (with Silva)’’ featuring a rational model in closed form for the parallel bars system (PBS). This paper was a precursor to his later interest in statistical damage mechanics of lattice models. In those years other important papers were also published (with few excurses on spall fracture). In 1984, the Applied Mechanics Review invited Dusan to present the paper on ‘‘Continuous Damage Mechanics’’. Perhaps this was the first occasion to survey the work done on damage theory and depict the state of the art of the damage theory at that time. In 1987, a paper with R. Ilankamban discusses the kinetics of damage evolution and points out the effect of loading onto the failure envelope and stiffness tensor. In the same year he also published a biomechanics paper containing a damage model for Cortical Bone. Many of his papers on continuum models (also on plasticity) continued to appear also in the 90s, with a tensor representation of the damage parameter. At the beginning of the 90s, Dusan had clear in his mind the limitations of the micromechanics models for large damage densities as well as the size effects associated to failure of concrete. He was looking for other approaches, alternative to both the RVE models and phenomenological models of continuum damage mechanics available at that point, to address these issues associated with the occurrence of the homogeneous–heterogeneous transition and damage localization. Like other researchers, on the wake of increasing feasibility of large simulations, Dusan started working on ‘‘statistical damage mechanics’’, employing discrete models similar to the PBS from 1982, such as spring networks. The goal was (and is) the development of a methodology to bridge the macroscale behavior and the microscale properties and predict the onset of failure. Along with discrete models, the mathematical framework of fractals seemed promising. ‘‘Fundamental Aspects of
1640
Guest Editorial / International Journal of Plasticity 23 (2007) 1637–1640
Brittle Cooperative Phenomena – Local Load Sharing Rules’’ and ‘‘Scaling Law for the Blue Cheese Model of Damage’’ from 1993 are emblematic. By the mid 90s, damage mechanics had become a widespread discipline and Dusan, always an attentive observer, set out to reorganize the material and the expertise accumulated so far. This culminated in his 1996 book ‘‘Damage Mechanics’’, which represents a milestone. It is a compendium (over 700 pages) of continuum and discrete theories that renders a broad perspective of damage mechanics and still is one of only two or three comprehensive references on the subject available to the scientific community. In the late 90s, the effort towards network models and scaling laws increased. By using molecular dynamics to study lattice structures in the time domain, he investigated dynamic damage, e.g. fragmentation processes and strain rate effect, of network structures. Representative papers are ‘‘Statistical Models of Brittle Deformation’’ in IJP (1999) and ‘‘High Velocity Expansion of a Cavity Within a Brittle Material’’ (with Mastilovic 1999). With the strenuous discipline and passion typical of an athlete (few know that Dusan in his youth was indeed a professional soccer player in the major league of former Yugoslavia) he relentlessly continues to pursue and inspire research. The papers ‘‘The Statistical Damage Mechanics – Part I & II’’ (05–06 with Rinaldi, Mastilovic) are a clear example in this respect and contain constitutive relations inspired by the fractal framework. The novel formulation, although still a partial result, finally yields scaling relations valid in both hardening and softening phase. Dusan always acknowledged his two mentors Dr. Nikola Hadjin and George Hermann. Dr. Hadjin is with the University of Belgrade and Serbian Academy of Sciences and Arts. Dusan, however, always took time to acknowledge the encouragement, understanding and patience of his lifetime partner and wife Tanya, as well as his daughters Ivan and Maya. This special volume is dedicated in memory to our friend and mentor Dusan Krajcinovic. We would like to end this dedication with one of his favorite quotes: He who does not expect the unexpected will not detect it. Democritus George Z. Voyiadjis Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA, United States Tel.: +1 225 578 8668; fax: +1 225 578 9176 E-mail address: [email protected] Antonio Rinaldi Department of Chemical Science and Technology, University ‘‘Tor Vergata’’, Rome, Italy Tel.: +39 480 965 8656 E-mail address: [email protected] Available online 12 March 2007
Guest Editorial
Dusan Krajcinovic: A biographical sketch
Dusan was awarded a B.Sc. (Golden Index as first in class) and a M.Sc. in Civil Engineering from University of Belgrade in 1958 and 1966 respectively. Dusan afterwards, he moved to USA to pursue his Ph.D. in Civil Engineering at Northwestern University, in Evanston, Illinois, which was completed in 1968 under the guidance of Professor George Hermann. He then began a brilliant and successful career in the characterization of material behavior, and the analysis and design of structures. He worked at Ingersoll Rand Research Inc. in 1969 and following that he moved to Argonne National Laboratory in the Theoretical and Applied Mechanics Group. In 1973, he left Argonne to go back to academia, although he would still be a staff member there until 1979. From 1973 to 1989 he was Professor of Civil Engineering at University of Illinois, Chicago, Illinois. He then moved to Arizona State University (ASU), Tempe, Arizona, in the Mechanical and Aerospace Engineering Department, where he stayed until he retired. Dusan has been a Professor Emeritus at ASU since 2004. During his long and fruitful career he gained the admiration of his peers. He was always invited and a main contributor to numerous National and International workshops, 0749-6419/$ - see front matter Ó 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.ijplas.2007.03.002
1638
Guest Editorial / International Journal of Plasticity 23 (2007) 1637–1640
scientific meetings, symposia, conferences, etc. To name a few of these scientific gatherings were the 1989 NATO Advanced Study Institute on Disorder and Fracture (J.C. Charmet, C. Roux and E. Guyon), and the 1992 Institute of Theoretical Physics at the University of California, Santa Barbara (J. Langer and J.R. Rice). His career is multifaceted and reflects Dusan’s personality, ability and versatility. His record of professional and academic achievements is vast and impressive. As a professional engineer he was involved in the design of major concrete structures. A notable example is the 90 m high concrete arch dam in Glazanj, where he was in charge of the structural analysis. He was an active consultant also in the areas of fracture and damage mechanics. The list of consulting companies and institutions that he worked for is long and encompasses prestigious international names, such as Energoprojekt, Argonne National Laboratory, the US Department of Interior (member of a panel of USA experts in the USA–USSR U-25 test series in Moscow), Procedyne Corp., Conselho de Gestao, Gabinete da Area de Sines (Portugal), Sargent and Lundy Engineers, The World Bank, Lufthans, Enrico Fermi National Accelerator Laboratory, Paslode Co.,The University of Michigan, Wiss, Janney, Elstner Associates Inc., Sandia National Laboratories, Allied Signal, Arizona Power, Ad Tech, and SelectTech Services Corporation. Technical contributions, such as ‘‘Structural Failures, Attorney’s Guide to Engineering (with P. Popovic)’’ or ‘‘Selected Topics in Dynamic Stability (with R. Plaut, G. Simitses and S.S. Chen)’’, Ch. 19 in ‘‘Guide to Stability Design Criteria for Metal Structures’’ clearly demonstrate his attention towards the industry and non-academic community. In this specially dedicated volume, however, we wish to honor the memory of the academician for his scientific merit and dedication. His research has had a profound impact on the development of damage mechanics of brittle materials. His opinion has been extremely influential and highly regarded in the scientific community. Dusan has been a prolific researcher and co-authored over 200 publications, including refereed journals, proceedings, contributed chapters, co-edited books and his own book on damage mechanics. His is a well known authority in the field of damage mechanics. He has been for many years organizer of a number of short courses and symposia in damage mechanics worldwide. Dusan has received a number of awards, such as the October Prize for Mathematical, Physical and Engineering Science (Belgrade, Yugoslavia 1990), the Gold Medal for achievements in Science and Technology (Crete 1999) and Laurea Honoris Causa (Milan Italy, 2001). He was a member of many editorial boards of scientific journals, e.g. Applied Mechanics Reviews and Mechanics of Materials, and still is one of the chief editors of the International Journal of Damage Mechanics. Dusan was constantly involved with professional societies, such as ASME (fellow and president of AMD executive committee 2001–2002), American Academy of Mechanics (fellow and president 1999–2001), Stability Research Council, International Association for Structural Engineering in Reactor Technology and ASCE (non-member advisor of the Committee for Inelastic Behavior of Materials). Within the ASME he was also a Medal Committee member for the Timoshenko, Koiter, and Drucker Medals and organized international conferences such as MECMAT 03 in Scottsdale, AZ. We briefly review some landmark publications to depict a chronological outline of Dusan’s body of work. The first publications trace back to Dusan’s collaboration with Professor N. Hajdin between 1962 and 1965 when still in Belgrade. The first journal paper on thin-walled structures (Int. J. Sol. Struct. 1969) was published soon after his doctorate. In the best structural engineering tradition, thin walls structures, beams, shells and plates
Guest Editorial / International Journal of Plasticity 23 (2007) 1637–1640
1639
theory was to be the core of his research for another decade. Dusan analyzed problems related to dynamic response, stability and vibrations of these structures, often in combination with plasticity. His papers on dynamic response of circular rigid-plastic plates and beams (1975) are representative examples of that period. In a time when novel computer methods were coming to the fore, Dusan was a strong supporter of the computer revolution and promoter of structural matrix methods, as one can appreciate from his papers from the 70s. During that period, a few of his papers on nuclear technology also appeared, such as ‘‘Fluid–Solid Interaction of Reactor Components: A Preliminary Analysis’’ (with J. Carey 1974). Probably inspired by Budianski and O’Connel’s work (1976), Dusan published ‘‘Distributed Damage Theory of Beams in Pure Bending’’ in 1979, which marks a smooth transition into a brand new field of investigation. He was amongst the first scientists to research in damage mechanics and, from that moment, he would dedicate himself almost entirely to it (setting aside few occasional papers on plasticity). In 1981, he published ‘‘The Continuous Damage Theory of Brittle Materials, Part I & II: Uniaxial and Plane Response Modes’’ (with G.U. Fonseka), where a family of vectors is used to represent microscale damage in an elastic brittle solid, typically concrete. The theory offered a simple approach to treat unilateral conditions and to rationally derive a damage measure based on the microstructure but independently of the applied load. Limitations of this simple approach under complex strain states were pointed out, for example, by Chaboche. Hovewer, this often cited work contributed to highlighting the controversial mathematical nature of the damage variable. Damage models based on fracture mechanics and micromechanics would be distinctive of Dusan’s work in the 80s. In 1982, Dusan explored the relation between strength theory and damage and published the work on ‘‘Statistical Aspects of the Continuous Damage Theory (with Silva)’’ featuring a rational model in closed form for the parallel bars system (PBS). This paper was a precursor to his later interest in statistical damage mechanics of lattice models. In those years other important papers were also published (with few excurses on spall fracture). In 1984, the Applied Mechanics Review invited Dusan to present the paper on ‘‘Continuous Damage Mechanics’’. Perhaps this was the first occasion to survey the work done on damage theory and depict the state of the art of the damage theory at that time. In 1987, a paper with R. Ilankamban discusses the kinetics of damage evolution and points out the effect of loading onto the failure envelope and stiffness tensor. In the same year he also published a biomechanics paper containing a damage model for Cortical Bone. Many of his papers on continuum models (also on plasticity) continued to appear also in the 90s, with a tensor representation of the damage parameter. At the beginning of the 90s, Dusan had clear in his mind the limitations of the micromechanics models for large damage densities as well as the size effects associated to failure of concrete. He was looking for other approaches, alternative to both the RVE models and phenomenological models of continuum damage mechanics available at that point, to address these issues associated with the occurrence of the homogeneous–heterogeneous transition and damage localization. Like other researchers, on the wake of increasing feasibility of large simulations, Dusan started working on ‘‘statistical damage mechanics’’, employing discrete models similar to the PBS from 1982, such as spring networks. The goal was (and is) the development of a methodology to bridge the macroscale behavior and the microscale properties and predict the onset of failure. Along with discrete models, the mathematical framework of fractals seemed promising. ‘‘Fundamental Aspects of
1640
Guest Editorial / International Journal of Plasticity 23 (2007) 1637–1640
Brittle Cooperative Phenomena – Local Load Sharing Rules’’ and ‘‘Scaling Law for the Blue Cheese Model of Damage’’ from 1993 are emblematic. By the mid 90s, damage mechanics had become a widespread discipline and Dusan, always an attentive observer, set out to reorganize the material and the expertise accumulated so far. This culminated in his 1996 book ‘‘Damage Mechanics’’, which represents a milestone. It is a compendium (over 700 pages) of continuum and discrete theories that renders a broad perspective of damage mechanics and still is one of only two or three comprehensive references on the subject available to the scientific community. In the late 90s, the effort towards network models and scaling laws increased. By using molecular dynamics to study lattice structures in the time domain, he investigated dynamic damage, e.g. fragmentation processes and strain rate effect, of network structures. Representative papers are ‘‘Statistical Models of Brittle Deformation’’ in IJP (1999) and ‘‘High Velocity Expansion of a Cavity Within a Brittle Material’’ (with Mastilovic 1999). With the strenuous discipline and passion typical of an athlete (few know that Dusan in his youth was indeed a professional soccer player in the major league of former Yugoslavia) he relentlessly continues to pursue and inspire research. The papers ‘‘The Statistical Damage Mechanics – Part I & II’’ (05–06 with Rinaldi, Mastilovic) are a clear example in this respect and contain constitutive relations inspired by the fractal framework. The novel formulation, although still a partial result, finally yields scaling relations valid in both hardening and softening phase. Dusan always acknowledged his two mentors Dr. Nikola Hadjin and George Hermann. Dr. Hadjin is with the University of Belgrade and Serbian Academy of Sciences and Arts. Dusan, however, always took time to acknowledge the encouragement, understanding and patience of his lifetime partner and wife Tanya, as well as his daughters Ivan and Maya. This special volume is dedicated in memory to our friend and mentor Dusan Krajcinovic. We would like to end this dedication with one of his favorite quotes: He who does not expect the unexpected will not detect it. Democritus George Z. Voyiadjis Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA, United States Tel.: +1 225 578 8668; fax: +1 225 578 9176 E-mail address: [email protected] Antonio Rinaldi Department of Chemical Science and Technology, University ‘‘Tor Vergata’’, Rome, Italy Tel.: +39 480 965 8656 E-mail address: [email protected] Available online 12 March 2007