Full Member of the Academy of Athens, the most prestigious academic institute in Greece with 40 members in all its three sections, in the chair of Theoretical and Experimental Mechanics (2016). Diploma in Civil Engineering of the National Technical University of Athens (NTUA) (1971), Ph.D. of NTUA (1973). Instructor in the Chair of Theoretical and Applied Mechanics of NTUA (1974-1977). Professor (with no tenure) (1977-1980), Chair Professor (1980-1982) and Professor (1980-2015) of Applied Mechanics of the Democritus University of Thrace (DUTH). Director of the Laboratory of Applied Mechanics (1977-1015), Director of the Section of Design & Construction of Structures (1983-1986 & 1993-1998), Director of the Section of Mechanics (2002 – 2010), Chairman of the Department of Civil Engineering (1987-1989) and Vice Chairman of the Research Committee (1994-1997) of DUTH. Chair of the Division of Natural Sciences of the Academy of Athens (2019). Visiting Professor of the universities of Toledo, Lehigh, Michigan Technological University, University of California at Santa Barbara & Davis, Northwestern University and Clark Millikan Distinguished Visiting Professor of the California Institute of Technology of USA. Corresponding member of the Academy of Athens (2007), member of the European Academy of Sciences and Arts (2001), European Academy of Sciences (2008), Academia Europaea (2008), International Academy of Engineering (2010), Fellow of the American Academy of Mechanics (2007) & the New York Academy of Sciences (2001), Foreign Fellow of the Russian Academy of Engineering (2009), Bulgarian Academy of Sciences (2010), Russian Academy of Sciences (2016) & Ukrainian Academy of Sciences (2021). Honorary member of the Italian Society of Fracture Mechanics (2004), Polish (2009) & Serbian (2011) Societies of Theoretical and Applied Mechanics, Doctorate Honoris Causa of the University of Nis of Serbia (2013), the Russian Academy of Sciences (2010) & DUTH (2019). Fellow of the American Society of Mechanical Engineers (1993), the Society for Experimental Mechanics (2004), the European Structural Integrity Society (2008), the European Society for Experimental Mechanics (2010), the International Congress on Fracture (2009) American Association for the Advancement of Science (2012). Honorary member of the Literary Society “Parnassos” (2020). President of the Society of Experimental Mechanics (2013-2014), the European Structural Integrity Society (2006-2010), the European Society for Experimental Mechanics (2004-2007) and Vice-President of the International Congress on Fracture (2013-2017). Recipient of the awards: “Award of Merit” (2008), “Griffith Medal” (2010) of the European Structural Integrity Society, “Theocaris Award” (2009), “Lazan Award” (2009), “Tatnall Award” (2010) “Zandman Award” (2011) of the Society of Experimental Mechanics, Medal and Diploma of the “International Academic Rating of Popularity Golden Fortune” (2009), “Paton Medal” of the Ukrainian Academy of Sciences (2009), “Jubilee Medal XV Year IAE” of the International Academy of Engineering (2009), “Award of Merit” (2010), “Theocaris Award” (2012) of the European Society for Experimental Mechanics, “Golden Sign” of the Russian Academy of Engineering (2011), SAGE Best Paper Award (2012), “Panetti-Ferrari Prize” of the Turin Academy of Sciences (2012), “Colonnetti Gold Medal” of the Italian Research Institute of Metrology (2012), “Blaise Pascal Medal in Engineering 2018,” of the European Academy of Sciences “Yokobori Medal” of the International Congress of Fracture (2017), “Timoshenko Mechanics Lecture Award”, Louisiana State University (2020), “Award of the Rotary Club of Mytilini”, Greece for “his invaluable contributions in engineering mechanics and higher education” (2019) “Archon, Teacher of the Nation” of the Patriarchate of Alexandria and Africa (2018). President of the Hellenic Society of Linguistic Heritage (2018-now) and the Theocaris Foundation (2018-now). President of many national and international conferences. Published more than 130 papers in international scientific journals and more than 180 in conference proceedings. Author of 9 books in Greek, 7 books in English published by international publishers (Springer, Elsevier, Kluwer Academic Publishers, Martinus Nijhoff Publishers), editor of 25 books published by the above publishers. His book “Fracture Mechanics – An Introduction” accompanied by “Solutions Manual” is used as a textbook by many universities worldwide. Editor-in-chief of “Strain – An International Journal of Experimental Mechanics,” (2007-2010), guest editor of special issues of international journals, associate editor and member of the editorial board of 12 international scientific journals. Editor of the series of “Springerbriefs in Structural Mechanics” of Springer. He presented more than 80 plenary/invited lectures in conferences/universities. His research interest include problems of the theory of elasticity, use of complex functions for the solution of problems of mechanics, fracture mechanics, experimental mechanics (with emphasis in the optical methods), mechanics of composite materials, sandwich structures and nanotechnology (composite nanomaterials). In 2015 the journal Meccanica devoted a special issue in his honor. He is honorary citizen of the municipality of Lesvos (Greece), (2012).