Invitation to the Research Colloquium - Double Colloquium: Lectures by Prof. Dr. Carlos Manuel Lázaro Fernández, Valencia as well as by Martin Fußeder M.Sc., TUM

As part of the research colloquium for thesis, doctoral and postdoctoral students, we cordially invite you to the double colloquium on June 20, 2023 at Mönchebergstr. 7, room 3516.

4.30 pm starts the lecture of

Prof. Dr. Carlos Manuel LázaroFernández, Universidad Politècnica de València and Department of Mechanics of Continuous Media and Theory of Structures, TUM Chair of Statics on the topic Two Lightweight Structures with Steel-Fiber Reinforced Concrete.

 Two different projects of lightweight structures using steel-fibre reinforced concrete will be presented.

The first project is a recreation of Felix Candela's famous "Los Manantiales" hypar shell in Mexico: the Oceanogràfic restaurant roof (Valencia, 2000) is considered to be Candela's last built project, and is one of the first examples of use of steel-fibre reinforced concrete in architectural shell construction. We address the challenges and the solutions to design and build the shell roof according to Candela's philosophy in a context where the knowledge of designing and building thin concrete shells was practically lost.

The second project has a very different character: it is an experimental small footbridge with a bending-active deck of ultra-high performance fiber-reinforced concrete (UHPFRC). We have explored the possibility to pre-bend slender UHPFRC members to improve the shape of the structure. The footbridge prototype follows the bending-active bow-string concept. It has a span length of 5.4 m and is composed of a thin prestressed upper slab, a deviator and lower stainless-steel tensioning cables. The prototype takes advantage of the capacity of UHPFRC to resist traction and bending with microcracking in service conditions. 

17.30 h follows the lecture of 

Martin Fußeder M.Sc. (lecturer) and Prof. Dr. Ing. Kai-Uwe Bletzinger TU-Munich, TUM School of Engineering and Design, Chair of Statics on the subject of

A Computational Engineering Tool for Sensitivity Analysis Based on the Method of Influence Functions.

The method of influence functions is a well-known engineering tool in structural analysis to investigate the consequences of load variations on deflections and stress resultants. Based on its strong relationship with adjoint sensitivity analysis [1,2] the method of influence functions can be generalized [3]. We show the connection of the two approaches and demonstrate in particular how influence functions can be identified as a sub-result of adjoint sensitivity analysis. Based on this knowledge, we propose a concept for the generalization of the method of influence functions as a tool for the computation of sensitivities. The traditional influence function approach can be seen as work balance based on Betti's theorem. In our contribution we show how that work expression can be extended for sensitivity analysis with respect to various parameters. We discuss the significance of the resulting mechanically interpretable sensitivity analysis and its limitations. In that regard, we also specify how the graphical analysis procedure, for which the traditional influence function technique is well-known, can be generalized. The intention is to use those "sensitivity maps" to identify the positions of extreme influences and the individual effects of the partitions to the final sensitivity and its spatial distribution. In this way, structural analysis models of real-world engineering problems can be systematically explored and important model parameters can be identified.