On the morning of May 20, 2024, Professor Xiao Rui from the Department of Engineering Mechanics, School of Aeronautics and Astronautics at Zhejiang University, visited DGUT at the invitation of the university and delivered an engaging academic report titled "A Nonequilibrium Constitutive Theory for Polymers" at the Interdisciplinary Science Research Center. The exchange session was chaired by Dean Wang Biao of the School of Materials Science and Engineering and was conducted in a hybrid format combining online and in-person participation, drawing active involvement from dozens of faculty members and students from the School of Materials Science and Engineering and other relevant units.
In his report, Professor Xiao Rui focused on the complex stress-strain response characteristics of glassy polymers. Glassy polymers exhibit elastic behavior at small strains, strain softening at moderate strains, and strain hardening at large strains. These nonlinear mechanical behaviors hold significant implications for the application of polymers in engineering structures. To accurately describe such complex mechanical behaviors, Professor Xiao Rui's team developed a nonequilibrium thermodynamic theoretical framework based on the concept of equivalent temperature. This framework successfully predicts the effects of temperature, loading rate, physical aging, and pre-deformation on the stress response and deformation localization behavior of glassy polymers. Furthermore, the team introduced the equivalent temperature concept into the shear transformation zone model, establishing a novel micromechanical model that successfully predicts the anomalous stress relaxation behavior and the Bauschinger effect in glassy polymers. These research efforts provide new theoretical tools for understanding and predicting the mechanical behavior of glassy polymers. By accurately describing the stress-strain responses of glassy polymers under various conditions, this work not only contributes new perspectives to theoretical research in materials science, but also offers important references for the application of glassy polymers in fields such as aerospace, automotive manufacturing, and high-performance composite materials.
The report was rich in content and presented in an accessible manner, broadening the academic horizons of faculty and students alike, while also providing new ideas and impetus for the future development directions of the school, enabling it to better serve the needs of societal development and strive for further breakthroughs in the field of polymer mechanical behavior.
Biography:
Xiao Rui is a professor in the Department of Engineering Mechanics, School of Aeronautics and Astronautics at Zhejiang University. His research interests primarily include constitutive relations, soft matter mechanics, and mechanics of smart materials and structures. He has published over 70 SCI papers as first author or corresponding author in journals such as Journal of the Mechanics and Physics of Solids and International Journal of Plasticity. He has received honors including the National Natural Science Foundation's Excellent Young Scientists Fund, the Chinese Rheology Youth Award, the Wang Ren Youth Science and Technology Award, and the Humboldt Research Fellowship.
Written by: Zhang Chenxu
First Review: Liu Zhao / Second Review: Li Runxia / Third Review: Wang Biao
