- Email: [email protected]
In honor of Akhtar S. Khan
International Journal of Plasticity 27 (2011) 1457–1458
Contents lists available at ScienceDirect
International Journal of Plasticity journal homepage: www.elsevier.com/locate/ijplas
Editorial
In honor of Akhtar S. Khan
This issue is dedicated to Professor Akhtar Salamat Khan. The papers are taken from a minisymposium organized by us in his honor, as part of celebrating 25 years of International Journal of Plasticity and International Symposium on Plasticity and its Current Applications, in St. Kitts, West Indies, January 3–8, 2010. Twenty-six years ago, Professor Khan had the vision for The International Journal of Plasticity, right after the First International Symposium on Plasticity and its Current Applications in Norman, Oklahoma, that he organized in honor of his mentor, late Professor James F. Bell of the Johns Hopkins University. Since then, Akhtar has coalesced the plasticity research community into a vibrant research family by providing these two platforms for research dissemination. The conference is now organized every year, and is attended by 300–375 plasticity researchers. It is the largest assembly of plasticity researchers each year, featuring presentations of the highest caliber. Among scientists who have participated in this conference series more than once, include late Professors Drucker, Krempl and Boehler, as well as, Professors Atluri, Clifton, Gerbrich, Gurtin, Nemat-Nasser, Nix, Perzyna, and numerous distinguished younger scientists. The journal has grown steadily in prestige and size over these years, its most recent impact factor (in 2010) is over five. The impact factor has been highest among all established Elsevier mechanics and materials science journals for the past several years. Akhtar had a very humble beginning. He was born in the tiny, remote village of Binohni in India, near its boundary with Nepal. His primary education started under a tree, as the village then, did not have a building for school. He moved to a university town, Aligarh, near Delhi, where his father was a professor of English. Then, he was educated at Aligarh Muslim University, Aligarh, UP, India. He received two BS degrees, one in Physics, Mathematics and Chemistry, and the other in Mechanical Engineering, in 1961 and 1965, respectively. He received both degrees with honors and a first rank. He received his Ph.D. in Mechanics and Materials Science from The Johns Hopkins University, in 1972. The same year, Akhtar married Tanveer; she is a great supporter and his lifetime friend. They have one daughter, Meena and one son, Farhan and three grand-daughters from Meena. After a one year Post-Doctoral fellowship at The Johns Hopkins University, he worked at a few industries for five years; Arthur McKee in Cleveland and The Bechtel Power Corp. (Nuclear Division in Gaithersburg), before accepting his first faculty position at the School of Aerospace and Mechanical Engineering, at The University of Oklahoma in 1978, where he received tenure in 1981 and became a full professor in 1984. He was invited to be the first Director/Chairman of the Mechanical Engineering Department, The University of Maryland-Baltimore County (UMBC) in 1992, where he served as the Chairman until 1995. The Army Research Office established a Center of Excellence for Materials Research under his overall coordination, with other colleagues in the Department, as well as in other departments at UMBC in 1995. Professor Khan has been a balanced faculty member, teaching undergraduate and graduate courses, writing textbooks, editing the international journal that he conceived and developed over the years, organizing the conference series that he also conceived and developed over the years, mentoring doctoral students, and writing papers with his students. He is the lead coauthor of ‘‘Continuum Theory of Plasticity’’ published in 1995; it has become the lead reference book for plasticity researchers for past 16 years. It has been used as textbook for graduate courses on plasticity at leading universities of the world, including MIT, Georgia Tech., University of California, Berkley and Texas A&M University. He is also a lead-coauthor of ‘‘Elementary Strain Measurements and Stress Analysis’’, an 0749-6419/$ - see front matter Ó 2011 Published by Elsevier Ltd. doi:10.1016/j.ijplas.2011.07.004
1458
Editorial / International Journal of Plasticity 27 (2011) 1457–1458
undergraduate textbook on experimental techniques. We list some important and/or highly cited papers below, selected from his extensive list of publications, which represent his research interests in the areas of plasticity under non-proportional loading, at high strain rates and temperatures, and from conventional metals to emerging materials including polymers and nanocrystalline metals. In the papers with his former doctoral student, now Professor Xinwei Wang in China [1,3], they first established a need for non-associative constitutive model. The first paper on non-associative constitutive model was published in International Journal of Plasticity in 2002. Since then, there are many research articles on non-associated plastic flow in many journals. In [3], Professors Khan & Wang established that yield surfaces based on any strain definition, 500-2000 micro-strain, had isotropic & kinematic hardening, and distortion. This has been further shown [8] true even for much smaller strain definition of yield. Akhtar and his former doctoral students have contributed Khan-Huang-Liang (KHL) hardening model for high strain rate plastic deformation in metals [2], the model has been further developed [4,5,7] to predict deformation over a very wide strain rate and temperature ranges in metals with different crystalline structures. For more than a decade, his research group has been interested in nanocrystalline metals [6,9], where they have fabricated high quality metals with very high ductility (in excess of 50% strain in compression) for the first time in his laboratory. The KHL model has been modified to Khan-Liang-Farrokh (KLF) model to take into account the dependence of the response of these models (yield stress and work hardening) on grain size. 1. Khan, A.S., Wang, X. On non-proportional infinitesimal plastic deformation after finite plastic prestraining and partial unloading (1988) Journal of the Mechanics and Physics of Solids, 36(5), pp. 519–535. 2. Khan, A.S., Huang, S. Experimental and theoretical study of mechanical behavior of 1100 aluminum in the strain rate range 10-5-104s-1 (1992) International Journal of Plasticity, 8(4), pp. 397–424. 3. Khan, A.S., Wang, X. An experimental study on subsequent yield surface after finite shear prestraining (1993) International Journal of Plasticity, 9 (8), pp. 889–905. 4. Liang, R., Khan, A.S. A critical review of experimental results and constitutive models for BCC and FCC metals over a wide range of strain rates and temperatures (1999) International Journal of Plasticity, 15(9), pp. 963–980. 5. Khan, A.S., Liang, R. Behaviors of three BCC metal over a wide range of strain rates and temperatures: Experiments and modeling (1999) International journal of plasticity, 15(10), pp. 1089–1109. 6. Khan, A.S., Suh, Y.S., Chen, X., Takacs, L., Zhang, H. Nanocrystalline aluminum and iron: Mechanical behavior at quasi-static and high strain rates, and constitutive modeling (2006) International Journal of Plasticity, 22(2), pp. 195–209. 7. Khan, A.S., Kazmi, R., Farrokh, B. Multiaxial and non-proportional loading responses, anisotropy and modeling of Ti–6Al–4V titanium alloy over wide ranges of strain rates and temperatures (2007) International Journal of Plasticity, 23(6), pp. 931–950. 8. Khan, A.S., Kazmi, R., Pandey, A., Stoughton, T. Evolution of subsequent yield surfaces and elastic constants with finite plastic deformation. Part-I: A very low work hardening aluminum alloy (Al6061-T6511) (2009) International Journal of Plasticity, 25(9), pp. 1611–1625. 9. Farrokh, B., Khan, A.S. Grain size, strain rate, and temperature dependence of flow stress in ultra-fine grained and nanocrystalline Cu and Al: Synthesis, experiment, and constitutive modeling (2009) International Journal of Plasticity, 25(5), pp. 715– 732. Professor Khan and his wife, Dr. Tanveer A. Khan, have established the Khan International Award for life-long outstanding contributions to the field of plasticity in 2006, to recognize established stars in the field of plasticity. The award is based on twenty years of contributions prior to the award. The recipients of this award since 2006 are Jean-Louis Chaboche, Lallit Anand, David McDowell, Nobutada Ohno, Hussein Zbib and Robert Wagoner. The recipients receive a small amount of money, but more importantly, a minisymposium is organized in their honor a year after the award. A special issue of the International Journal of Plasticity in their honor will be published approximately one year after the minisymposium. Each recipient then becomes a member of the selection committee for the next five years. The current committee therefore consists of Professors Chaboche, Anand (Chair), McDowell, Ohno & Zbib. Each year, the new recipient will replace the senior- most member of the committee. In order to recognize rising stars in the field of plasticity, Akhtar established another prestigious award, beginning in 2006, the International Journal of Plasticity Award; this award is based on five years of contributions prior to the award year for an outstanding young researcher, preferably within fifteen years (twelve years starting this year) of his/her doctoral degree. Since its inception, the recipients are Professors Frederick Barlat, Yongang Huang, Jeong-Whan Yoon, Peidong Wu, Sean Angew and Mark Horstemeyer. The funds for this award are provided by Elsevier Science, Ltd. Just like other awarded recognized stars in the field, the new recipient each year, replaces the senior most member of the committee. The committee this year includes Drs. Barlat (Chair), Huang, Yoon, Wu & Agnew. The guest-editors and all of the contributing authors are very pleased to dedicate this special issue to Professor Khan for his remarkable vision, and exceptional contributions to the international plasticity research community through the International Journal of Plasticity, and International Symposium on Plasticity and Its Current Applications, as well as his research contributions to the field of plasticity. This issue contains 14 papers in conventional and emerging materials with various length scales ranging from nano to continuum level. Jeong Whan Yoon Swinburne University of Technology, Melbourne, Australia Amit Misra Los Alamos National Laboratory, NM, USA
Contents lists available at ScienceDirect
International Journal of Plasticity journal homepage: www.elsevier.com/locate/ijplas
Editorial
In honor of Akhtar S. Khan
This issue is dedicated to Professor Akhtar Salamat Khan. The papers are taken from a minisymposium organized by us in his honor, as part of celebrating 25 years of International Journal of Plasticity and International Symposium on Plasticity and its Current Applications, in St. Kitts, West Indies, January 3–8, 2010. Twenty-six years ago, Professor Khan had the vision for The International Journal of Plasticity, right after the First International Symposium on Plasticity and its Current Applications in Norman, Oklahoma, that he organized in honor of his mentor, late Professor James F. Bell of the Johns Hopkins University. Since then, Akhtar has coalesced the plasticity research community into a vibrant research family by providing these two platforms for research dissemination. The conference is now organized every year, and is attended by 300–375 plasticity researchers. It is the largest assembly of plasticity researchers each year, featuring presentations of the highest caliber. Among scientists who have participated in this conference series more than once, include late Professors Drucker, Krempl and Boehler, as well as, Professors Atluri, Clifton, Gerbrich, Gurtin, Nemat-Nasser, Nix, Perzyna, and numerous distinguished younger scientists. The journal has grown steadily in prestige and size over these years, its most recent impact factor (in 2010) is over five. The impact factor has been highest among all established Elsevier mechanics and materials science journals for the past several years. Akhtar had a very humble beginning. He was born in the tiny, remote village of Binohni in India, near its boundary with Nepal. His primary education started under a tree, as the village then, did not have a building for school. He moved to a university town, Aligarh, near Delhi, where his father was a professor of English. Then, he was educated at Aligarh Muslim University, Aligarh, UP, India. He received two BS degrees, one in Physics, Mathematics and Chemistry, and the other in Mechanical Engineering, in 1961 and 1965, respectively. He received both degrees with honors and a first rank. He received his Ph.D. in Mechanics and Materials Science from The Johns Hopkins University, in 1972. The same year, Akhtar married Tanveer; she is a great supporter and his lifetime friend. They have one daughter, Meena and one son, Farhan and three grand-daughters from Meena. After a one year Post-Doctoral fellowship at The Johns Hopkins University, he worked at a few industries for five years; Arthur McKee in Cleveland and The Bechtel Power Corp. (Nuclear Division in Gaithersburg), before accepting his first faculty position at the School of Aerospace and Mechanical Engineering, at The University of Oklahoma in 1978, where he received tenure in 1981 and became a full professor in 1984. He was invited to be the first Director/Chairman of the Mechanical Engineering Department, The University of Maryland-Baltimore County (UMBC) in 1992, where he served as the Chairman until 1995. The Army Research Office established a Center of Excellence for Materials Research under his overall coordination, with other colleagues in the Department, as well as in other departments at UMBC in 1995. Professor Khan has been a balanced faculty member, teaching undergraduate and graduate courses, writing textbooks, editing the international journal that he conceived and developed over the years, organizing the conference series that he also conceived and developed over the years, mentoring doctoral students, and writing papers with his students. He is the lead coauthor of ‘‘Continuum Theory of Plasticity’’ published in 1995; it has become the lead reference book for plasticity researchers for past 16 years. It has been used as textbook for graduate courses on plasticity at leading universities of the world, including MIT, Georgia Tech., University of California, Berkley and Texas A&M University. He is also a lead-coauthor of ‘‘Elementary Strain Measurements and Stress Analysis’’, an 0749-6419/$ - see front matter Ó 2011 Published by Elsevier Ltd. doi:10.1016/j.ijplas.2011.07.004
1458
Editorial / International Journal of Plasticity 27 (2011) 1457–1458
undergraduate textbook on experimental techniques. We list some important and/or highly cited papers below, selected from his extensive list of publications, which represent his research interests in the areas of plasticity under non-proportional loading, at high strain rates and temperatures, and from conventional metals to emerging materials including polymers and nanocrystalline metals. In the papers with his former doctoral student, now Professor Xinwei Wang in China [1,3], they first established a need for non-associative constitutive model. The first paper on non-associative constitutive model was published in International Journal of Plasticity in 2002. Since then, there are many research articles on non-associated plastic flow in many journals. In [3], Professors Khan & Wang established that yield surfaces based on any strain definition, 500-2000 micro-strain, had isotropic & kinematic hardening, and distortion. This has been further shown [8] true even for much smaller strain definition of yield. Akhtar and his former doctoral students have contributed Khan-Huang-Liang (KHL) hardening model for high strain rate plastic deformation in metals [2], the model has been further developed [4,5,7] to predict deformation over a very wide strain rate and temperature ranges in metals with different crystalline structures. For more than a decade, his research group has been interested in nanocrystalline metals [6,9], where they have fabricated high quality metals with very high ductility (in excess of 50% strain in compression) for the first time in his laboratory. The KHL model has been modified to Khan-Liang-Farrokh (KLF) model to take into account the dependence of the response of these models (yield stress and work hardening) on grain size. 1. Khan, A.S., Wang, X. On non-proportional infinitesimal plastic deformation after finite plastic prestraining and partial unloading (1988) Journal of the Mechanics and Physics of Solids, 36(5), pp. 519–535. 2. Khan, A.S., Huang, S. Experimental and theoretical study of mechanical behavior of 1100 aluminum in the strain rate range 10-5-104s-1 (1992) International Journal of Plasticity, 8(4), pp. 397–424. 3. Khan, A.S., Wang, X. An experimental study on subsequent yield surface after finite shear prestraining (1993) International Journal of Plasticity, 9 (8), pp. 889–905. 4. Liang, R., Khan, A.S. A critical review of experimental results and constitutive models for BCC and FCC metals over a wide range of strain rates and temperatures (1999) International Journal of Plasticity, 15(9), pp. 963–980. 5. Khan, A.S., Liang, R. Behaviors of three BCC metal over a wide range of strain rates and temperatures: Experiments and modeling (1999) International journal of plasticity, 15(10), pp. 1089–1109. 6. Khan, A.S., Suh, Y.S., Chen, X., Takacs, L., Zhang, H. Nanocrystalline aluminum and iron: Mechanical behavior at quasi-static and high strain rates, and constitutive modeling (2006) International Journal of Plasticity, 22(2), pp. 195–209. 7. Khan, A.S., Kazmi, R., Farrokh, B. Multiaxial and non-proportional loading responses, anisotropy and modeling of Ti–6Al–4V titanium alloy over wide ranges of strain rates and temperatures (2007) International Journal of Plasticity, 23(6), pp. 931–950. 8. Khan, A.S., Kazmi, R., Pandey, A., Stoughton, T. Evolution of subsequent yield surfaces and elastic constants with finite plastic deformation. Part-I: A very low work hardening aluminum alloy (Al6061-T6511) (2009) International Journal of Plasticity, 25(9), pp. 1611–1625. 9. Farrokh, B., Khan, A.S. Grain size, strain rate, and temperature dependence of flow stress in ultra-fine grained and nanocrystalline Cu and Al: Synthesis, experiment, and constitutive modeling (2009) International Journal of Plasticity, 25(5), pp. 715– 732. Professor Khan and his wife, Dr. Tanveer A. Khan, have established the Khan International Award for life-long outstanding contributions to the field of plasticity in 2006, to recognize established stars in the field of plasticity. The award is based on twenty years of contributions prior to the award. The recipients of this award since 2006 are Jean-Louis Chaboche, Lallit Anand, David McDowell, Nobutada Ohno, Hussein Zbib and Robert Wagoner. The recipients receive a small amount of money, but more importantly, a minisymposium is organized in their honor a year after the award. A special issue of the International Journal of Plasticity in their honor will be published approximately one year after the minisymposium. Each recipient then becomes a member of the selection committee for the next five years. The current committee therefore consists of Professors Chaboche, Anand (Chair), McDowell, Ohno & Zbib. Each year, the new recipient will replace the senior- most member of the committee. In order to recognize rising stars in the field of plasticity, Akhtar established another prestigious award, beginning in 2006, the International Journal of Plasticity Award; this award is based on five years of contributions prior to the award year for an outstanding young researcher, preferably within fifteen years (twelve years starting this year) of his/her doctoral degree. Since its inception, the recipients are Professors Frederick Barlat, Yongang Huang, Jeong-Whan Yoon, Peidong Wu, Sean Angew and Mark Horstemeyer. The funds for this award are provided by Elsevier Science, Ltd. Just like other awarded recognized stars in the field, the new recipient each year, replaces the senior most member of the committee. The committee this year includes Drs. Barlat (Chair), Huang, Yoon, Wu & Agnew. The guest-editors and all of the contributing authors are very pleased to dedicate this special issue to Professor Khan for his remarkable vision, and exceptional contributions to the international plasticity research community through the International Journal of Plasticity, and International Symposium on Plasticity and Its Current Applications, as well as his research contributions to the field of plasticity. This issue contains 14 papers in conventional and emerging materials with various length scales ranging from nano to continuum level. Jeong Whan Yoon Swinburne University of Technology, Melbourne, Australia Amit Misra Los Alamos National Laboratory, NM, USA