Prof. Dr. Di Song

Age: 35

My research areas: Solid mechanics: damage evolution and fatigue failure

Name of my University: University of Electronic Science and Technology of China

Research period at the TU Darmstadt: : 01.11.2020 to 30.04.2022 (Humboldt Research Fellowship for postdoctoral researchers)

Prof. Dr. Di Song

My field of research is fascinating. The best way to explain it to non-specialists in a comprehensible manner is:

My work is to clarify the effect of complex mechanisms on damage evolution and fatigue failure, and to find an efficient way to accurately predict the fatigue life of the metals and structures. Meanwhile, I also focus on the physical evolution law of both damage extent and microstructure variations during the cyclic loadings, especially for the metals which present various types of inelastic deformation mechanisms. These studies combined the theories of solid mechanics and material science, which is highly challenging for the researchers in the related disciplines.

What research questions are you currently working on?

I am currently working on the damage evolution and fatigue failure mechanism of high-strength steels, new models based on continuum damage mechanics and considering the evolution of the microstructures are greatly required, since the interactions between the micro-structures significantly complicate the mechanical behavior of the steels. The studies will provide a solid foundation for the structural design, life evaluation, and reliability analysis of the automotive components, and promote the development of multiscale solid mechanics.

I’ve chosen the TU Darmstadt because …

it is one of the top universities in Germany and famous for its engineering disciplines, the first-rate academic level and experimental installations makes this university as an ideal place for doing research. Meanwhile, my Humboldt host Prof. Dr.-Ing Vormwald is a well-known scientist in fatigue analysis of steels, and provides challenging topics for furthering my study. This research experience will greatly expand my research field, and improve my practicality of the investigations.

Prof. Dr. Di Song with her host Professor Dr.-Ing. Michael Vormwald (from the left).

My most important success in research to date is…

I gave the significant physical definitions for the unique mechanical behaviors of NiTi shape memory alloys, performed systematic non-proportional multiaxial fatigue simulations, and revealed their multiscale coupling mechanism in both macroscopic and microscopic fields. I am also the first to establish the damage evolution law, and propose the damage-based life prediction model for NiTi SMAs, which solved the problem of the large prediction error in complex loadings, and is regarded as the most accurate prediction model for NiTi SMAs up to now.

I became a researcher because …

I was fascinated in the principles of the machine operations since I was a little girl, so I studied hard at physics and selected mechanics as my major and research field since undergraduate stage. Meanwhile, the interests only cause you start the research, and the education that you receive will make you insist your research. I am very appreciated to all my supervisors since they are the guides in my academic road, they taught me the way of thinking and practice, and motivated me to solve the complex scientific issues. Their instruction makes me gradually grow into a researcher in these years.

What reputation does German research enjoy in your home country?

German research is famous for its high level and preciseness all over the world, and the scholar who has the German research experience is greatly approbatory in the Chinese academia, especially for the Humboldt Research Fellowship. There are many Chinese Humboldt researchers who have become the mainstays in their respective fields, and my doctoral supervisor Prof. Kang is one of them. He always encourages us to seek the chance of studying in Germany, and also apply for the Humboldt Research Fellowship. It is a potent support for broadening our academic vision in the German research.

Questionnaire for the host

Guest of: Professor Dr.-Ing. Michael Vormwald

Department: Civil and Environmental Engineering

What would you say you appreciate most about your guest or what made the most favourable impression on you…

Professor Song has worked extensively on the topic of fatigue of shape memory alloys. The modeling of the mechanical behavior of these materials poses extreme challenges to the researchers. Professor Song's contributions are characterized by the highest quality and originality.

Professor Dr.-Ing. Michael Vormwald

You, your team and the TU Darmstadt benefit from your guest’s…

Questions concerning the fatigue strength of components made of ultra-high-strength steels are burning issues. Professor Song has entered this area of research with her offer to complement our research with her contribution to multi-scale simulation of deformation and damage. This fits perfectly. The focus of our and her research has always been on the applicability of simulation algorithms in practice.