Event
【GIR Open Seminar】Dr. Frédéric Barlat / Pohang University of Science and Technology (Republic of Korea)・University of South Brittany (France)
| Date | 2025.2.14 (15：30 - 16：45) |
|---|---|
| Venue |
Lecture RoomL1341, 4F, Building 13, Koganei Campus, TUAT Meeting ID:842 2865 5225 Passcode:025207 |
| Google Classroom Code | sge4d2k |
| Speaker | Dr. Frédéric Barlat |
| Affiliation | Pohang University of Science and Technology / University of South Brittany (Republic of Korea / France) |
| Title | "DISTORTIONAL PLASTICITY AND CONTINUUM THERMODYNAMICS" ＜Abstract＞ A concise review of recent distortional plasticity models is provided in this presentation. Such models are efficient for the description of the plastic behavior of metals subjected to strain path changes. These changes are common during the forming operations of complex parts and must be accounted for in numerical simulations. This review underlines that the yield surface evolution can be described effectively with distortional plasticity. However, this comes at the expense of a number of state variables with their evolution equations. Compared with isotropic hardening, distortional plasticity models are more difficult to apply in practical problems. One of the main impediment comes from the complex optimization tools required for the identification of the model coefficients. However, one of such models, HEXAH, was designed to simplify this identification procedure. In fact, applications of HEXAH to advanced high strength steels, TRIP and DP, are given for illustration purpose in this presentation. It is shown that the determination of the model coefficients does not require complex optimization tools but just an old fashion trial-and-error method. Then, the classical continuum thermodynamics concepts applied to the constitutive models of plasticity are briefly discussed and illustrated with a simple example. It is shown that, within the framework of classical thermodynamics, it is very difficult to develop distortional plasticity models that lead to an accurate description of the material behavior. For this reason, a recently proposed unconventional thermodynamics approach that circumvent the drawbacks of the conventional approach is described in this presentation. It is shown that, if carefully developed, distortional plasticity models such as HEXAH provide an accurate description of the material behavior and are consistent with the requirement of thermodynamics. |
| Language | English |
| Intended for | Everyone is welcome to join. |
| Co-Organized by | Institute of Global Innovation Research "ENERGY" Pongsathorn Raksincharoensak Team Excellent Leader Development for Super Smart Society by New Industry Creation and Diversity |
| Contact | Institute of Global Innovation Research, Institute of Engineering Prof. Toshihiko Kuwabara e-mail: kuwabara（at）cc.tuat.ac.jp |
| Remarks | This seminar will be held both face-to-face and online concurrently. |
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