WIAS PhD Group
Apes together strong.
To the website of the group of PhD students at the Weierstrass-Institute for Applied Analysis and Stochastics!
| Date | Contribution |
|---|---|
| 21.10.2024 Main building, room 406! | Moritz Gau (WG 3) Dimension Reduction of a Thermo-visco-elastic Problem at Small Strains Abstract: The derivation of dimension-reduced models is a classical problem in continuum mechanics. In this talk, we consider a thermodynamically consistent nonlinear thermo-visco-elastic model at small strains for thin domains. The system of PDEs consists of the linear momentum equation (without inertia terms) for the displacement, coupled to the heat equation for the temperature. We discuss the rigorous derivation of an effective two-dimensional model for isotropic materials as the thickness of the plate tends to zero, extending results by Blanchard-Francfort 1987 and Licht 2013, who considered only linearised thermo-elasticity and visco-elasticity, respectively. By rescaling the domain to a fixed thickness, we prove suitable a priori estimates to ex- tract converging subsequences and pass to the limit. Since the viscous dissipation in the heat equation is only L1-integrable, the derivation of a priori estimates utilises appropriate nonlinear tests as invented by Boccardo-Gallou ̈et 1989. In the limit, the temperature becomes constant in the vertical direction and the displacement is of Kirchhoff–Love type, so that, in a certain sense, the limits only depend on the two-dimensional cross-section of the plate. The limiting model consists of three equations: the heat equation, and the mechanical equation splits into a membrane and a fourth-order flexural equation. Due to the viscous effects, the out-of-plane parts of the rescaled linearised strains (κbij) become solutions of ODEs in the limit. Especially κb33 obtains a more complex structure compared to elastic and thermo-elastic models, and it appears as in additional coupling in all three equations. This is a joint work with Matthias Liero (WIAS). |
| 25.11.2024 Main building, room 406! | Marwa Zainelabdeen (RG 3) tba Abstract: tba |
The PhD lunch is still alive and happening regularly! 🌮
Every Tuesday at 12:30, you are happily invited to join us for lunch! We meet in front of the entry to the main building! 🥪
As a result of the employee survey (Mitarbeiterbefragung MAB), a committee was set in place to develop appropriate measures for improving the working conditions at the institute.
One outgrowth of that was to institute a buddy group of volunteers who meet up monthly to offer a platform for discussing challenges and filling general gaps for newcomers to the WIAS.
See also:
the MAB committee's webpage (only reachable from within the WIAS via e.g. VPN)
You may have heard through the grapevine that the infamous WissZeitVG is currently in the process of being reformed.
While some suggestions seem to actually constitute an improvement - such as the plan to mandate (within limits) three-year contracts for newly hired PhDs - other parts of it have caused quite a stir in the German academic world. Most notably, the plan is to limit the maximum post-doc employment period under fixed-term contracts to only 3 years.
This has been met with severe criticism by labor unions, some research organizations and even professors who regard this development as significant in impacting the working conditions in academia in a negative fashion.
If you are interested in reading more about the general background and recent developments, especially from an English-speaking point of view, check out the following links:
Leibniz PostDoc Network: a network of postdoc scientists within the Leibniz Association engaging in information gathering, communcation, and advocacy.
#ProfsFürHanna: an alliance of professors who have co-signed an open letter calling for the revision of the proposed amendments to the WissZeitVG.
GEW [German]: Educators' and Scientists' Labor Union providing some details on the proposed amendments and reactions to them in German.
NGA - Network for Decent Labor in Academia [mostly German]: a network of mid-level academics in Germany engaged in information-gathering and advocacy for better working conditions in academia.
For German sources, we warmly recommend running bits of text through the DeepL Translator.
