Prof. Sergei Alexandrov
Beihang University, China; Ton Duc Thang University, Vietnam
Generation of material properties in the vicinity of the interface of two plastically deforming materials.
Narrow fine grain layers of material are often generated in the vicinity of bi-material interfaces in manufacturing processes of composite materials. These layers change properties of the composite. The latter affects the performance of structures and machine parts under service conditions. Therefore, it is of importance to develop a method to connect parameters of manufacturing processes and parameters that characterize properties of fine grain layers generated by these processes. The strain rate intensity factor is the coefficient of the leading singular term in a series expansion of the equivalent strain rate in the vicinity of maximum friction surfaces. Such expansions are available for several material models that are often adopted to describe the response of material in metal forming processes. The objective of the present paper is to develop a general approach to use the strain rate intensity factor for predicting the evolution of material properties within the fine grain layers. The paper includes a conceptual approach, experimental results on upsetting and drawing and a special numerical method for calculating the strain rate intensity factor. The latter is necessary since the strain rate intensity factor appears in singular solutions and conventional finite element methods are not capable of calculating this factor. The method proposed is based on the method of characteristics. Two criteria for the thickness of the fine grain layer are considered.
Plasticity theory, Constitutive Equations, Fracture mechanics, Modeling of Metal Forming Processes, Structural Design
Prof. Sergei Alexandrov is a Visiting Professor at Beihang University (Beijing, China) under the program “Recruitment Program for Global Experts” (“1000 Talent Plan”) and a Research Professor at the Laboratory for Technological Processes of the Institute for Problems in Mechanics of the Russian Academy of Sciences. He received his Ph.D. in Physics and Mathematics in 1990 and D.Sc. in Physics and Mathematics in 1994. He worked as a Professor at Moscow Aviation Technology Technical University (Russia), a Visiting Scientist at ALCOA Technical Center (USA), GKSS Research Centre (Germany) and Seoul National University (South Korea), and was a Visiting Professor at Aveiro University (Portugal), University of Besancon (France) and Technical University of Malaysia (Malaysia). He is a member of the Russian National Committee on Theoretical and Applied Mechanics. Prof. Sergei Alexandrov has published more than 400 papers in journals, books and conference proceedings, including three monographs and around 200 papers in journals indexed in the Web of Science. He has participated in the scientific committee of several international conferences and served as a reviewer in a wide range of international journals. He is on the editorial board of several journals including Continuum Mechanics and Thermodynamics (Springer) and Structural Engineering and Mechanics (Technopress). His research areas are plasticity theory, fracture mechanics, and their applications to metal forming and structural mechanics.