• Conference Object  

      3-D flow of Herschel-Bulkley fluids 

      Burgos, Gilmer R.; Alexandrou, Andreas N. (ASME, 1998)
      The flow of Herschel-Bulkley fluids through a sudden 3-D square with expansion height ratio of 2:1 is studied numerically by solving the mass and momentum conservation equations along with a continuous constitutive relation. ...
    • Article  

      Determination of the rheological parameters of self-compacting concrete matrix using slump flow test 

      Neophytou, Marina K. A.; Pourgouri, S.; Kanellopoulos, A. D.; Petrou, Michael F.; Ioannou, I.; Georgiou, G.; Alexandrou, Andreas N. (2010)
      The classification of a concrete mixture as self-compacting (SCC) is performed by a series of empirical characterization tests that have been designed to assess not only the flowability of the mixture but also its segregation ...
    • Article  

      Flow development in compression of a finite amount of a Bingham plastic 

      Florides, G. C.; Alexandrou, Andreas N.; Georgiou, G. C. (2007)
      The flow and shape evolution during the compression of a finite amount of a Bingham plastic is investigated by means of numerical simulations. The problem relates to the popular compression test used for the rheological ...
    • Article  

      Mathematical and computational modeling of die filling in semisolid metal processing 

      Alexandrou, Andreas N.; Bardinet, F.; Loué, W. (1999)
      A 'Bingham type', or Herschel-Bulkley constitutive relation capable of describing correctly the bulk behavior of the semisolid slurry is introduced. This relation is implemented in a modified version of the casting simulation ...
    • Doctoral Thesis  Open Access

      Numerical and semi-analytical solutions of viscoplastic Poiseuille and Couette flows 

      Chatzimina, Maria K. (Πανεπιστήμιο Κύπρου, Σχολή Θετικών και Εφαρμοσμένων Επιστημών / University of Cyprus, Faculty of Pure and Applied Sciences, 2009-01)
      Η παρούσα διατριβή περιλαμβάνει τις αριθμητικές και ημι-αναλυτικές λύσεις ιξωδοπλαστικών ροών Poiseuille και Couette. Αρχικά επιλύουμε αριθμητικά διάφορες ροές διακοπής ρευστών Bingham χρησιμοποιώντας το ομαλοποιημένο ...
    • Conference Object  

      Numerical simulation of die filling in semisolid metal processing 

      Bardinet, F.; Alexandrou, Andreas N.; Loue, Willem (Affiliation: WPI, Worcester, United StatesCorrespondence Address: Bardinet, FrancoisWPI, Worcester, United States, 1997)
      Semisolid Metal Processing offers distinct advantages over other near-net-shape technologies, such as a more homogeneous microstructure, less porosity and thus excellent mechanical properties. A perfect control of die ...
    • Article  

      On the early breakdown of semisolid suspensions 

      Alexandrou, Andreas N.; Georgiou, G. (2007)
      Semisolid materials are suspensions of metal alloys which are processed while in a mushy state. In this state, the suspensions behave as viscoplastic materials with time-dependent material properties. During processing, ...
    • Article  

      Parameter estimation for semi-solid aluminum alloys using transient experiments 

      Alexandrou, Andreas N.; Georgiou, G.; Tonmukayakul, N.; Apelian, D. (2006)
      A rotating vane-cup rheometer is used to determine the rheological properties of semi-solid slurries, and a procedure is established for characterizing the rheology with emphasis given to the proper and self-consistent ...
    • Conference Object  

      Rheological effects of strusture breakdown in semisolid slurries 

      Alexandrou, Andreas N.; Florides, G. C.; Georgiou, G. C.; Apelian, D. (Affiliation: Department of Mechanical and Industrial Engineering, University Cyprus, P.O.Box 20537, 1678 Nicosia, CyprusAffiliation: Department of Mathematics and Statistics, University of Cyprus, P.O.Box 20537, 1678 Nicosia, CyprusAffiliation: Metal Processing Institute, WPI, Worcester, MA, United StatesCorrespondence Address: Alexandrou, A.N.Department of Mechanical and Industrial Engineering, University Cyprus, P.O.Box 20537, 1678 Nicosia, Cyprus, 2004)
      An essential element for the integration of the semisolid metal (SSM) process in the production of complex commercial components is the availability of accurate mathematical and computational tools that could describe both ...
    • Conference Object  

      Rheology of semisolid suspensions 

      Alexandrou, Andreas N.; Burgos, G. R.; Entov, V. M. (Affiliation: Semisolid Processing Laboratory, Metal Processing Institute, WPI, Worcester, MA 01609, United StatesAffiliation: Polytech. University of Puerto Rico, Mechanical Engineering Department, San Juan 00918, Puerto RicoAffiliation: Institute for Problems in Mechanics, Russian Academy of Science, pr. Vemadskogo, 101, 117526 Moscow, Russian FederationCorrespondence Address: Alexandrou, A.N.Semisolid Processing Laboratory, Metal Processing Institute, WPI, Worcester, MA 01609, United States, 2000)
      The effective use of the semisolid process presumes a good theoretical framework to describe it. The understanding of semisolid behavior should be based upon a combination of basic and empirical knowledge in versatile ...
    • Article  

      Thixotropic rheology of semisolid metal suspensions 

      Burgos, G. R.; Alexandrou, Andreas N.; Entov, V. (2001)
      Understanding the time-dependent flow behavior of semisolid materials (SSM) is essential for the simulation of semisolid processes. During processing, the structure of the material changes with the processing history due ...
    • Conference Object  

      Thixotropy of semisolid metals 

      Alexandrou, Andreas N.; Burgos, G. R.; Entov, V. M. (Materials Research Society, 2000)
      Understanding the time-dependent flow behavior of metal alloys in semisolid state is essential for the further development of the process. In the present investigation, the thixotropic behavior of semisolid slurries is ...
    • Conference Object  

      Three dimensional flow of thixotropic materials in a channel with a sudden expansion using a phenomenological constitutive relation 

      Alexandrou, Andreas N. (Affiliation: WPI, Worcester, United StatesCorrespondence Address: Alexandrou, Andreas N.WPI, Worcester, United States, 1996)
      A constitutive relation is proposed that is capable of predicting a wide range of experimental rheological behavior depending on the proper choice of the parameters. The model represents the otherwise discontinuous Bingham ...
    • Conference Object  

      Time-dependent rheology of semisolid metal suspensions 

      Burgos, Gilmer R.; Alexandrou, Andreas N.; Entov, Vladimir (Affiliation: Metals Processing Inst, Worcester, United StatesCorrespondence Address: Burgos, Gilmer R.Metals Processing Inst, Worcester, United States, 1999)
      Understanding the time-dependent flow behavior of semisolid materials (SSM) is essential for the simulation of semisolid processes. During processing, the structure of the material changes with the processing history due ...
    • Article  

      Yield behavior of commercial Al-Si alloys in the semisolid state 

      Pan, Q. Y.; Apelian, D.; Alexandrou, Andreas N. (2004)
      Systematic experimental work and modeling efforts have been conducted to characterize the yield behavior of commercial aluminum alloys in the semisolid state. In this study, extensive compression experiments were performed ...