Advanced Structural Materials
Development and investigation of advanced structural materials (e.g. shape memory alloys) for use in civil infrastructure is our primary mission. The importance of building modern structures and the renovation and conservation of existing infrastructure increases, therefore, advanced structural materials to improve the load-carrying capacity and serviceability of infrastructure and designing new structures are required. Our research aims to make urban living easier, more sustainable, more comfortable, more secure and more functional. Within our research area, new materials and systems are developed and studied in small and large-scale size to show their application feasibility for civil infrastructure. Current research projects include:
- Feasibility study of a fiber reinforced polymer (FRP) composite train wheelset towards reduction in noise and weight
- Mechanical modeling of concrete members strengthened and prestressed by a novel iron-based shape memory alloy reinforcement
- Iron based Shape Memory Alloys as Shear Reinforcement for Civil Structures
- Investigation on the short-term and long-term behavior of the developed iron-based shape memory alloy at Empa
- Thermo-mechanical modeling of structures strengthened by iron-based shape memory alloy elements
To achieve our missions, we are strongly in collaboration with national and international research and industrial partners and experts in the field, including: material scientists, manufactures, acoustic scientists, electrochemistry scientists, engineering scientists and consulting and construction sectors. Our basic research and collaboration with industry result in “technology transfer” and “product development”.
Feasibility study of a fiber reinforced polymer (FRP) composite train wheelset towards reduction in noise and weight
Railway noise is often an important source of annoyance for people near the railways. The constantly increasing market demand in transport leads to a less calm transport system affecting many citizens both during the day and over the night. Within the scope of this project, feasibility of application of FRP composites materials to manufacture a train wheelset which, potentially, will generate less noise is studied. In addition to noise reduction, such FRP wheelsets will lead to weight savings which brings associated benefits of high-speed, reduced power consumption, lower inertia, less track wear and the ability to carry greater pay-loads. 3D finite element models are being developed to analyses the stresses and deflection of the FRP wheelset.
Involved staff: Moslem Shahverdi, Christoph Czaderski, Masoud Motavalli
- BAFU, Ittigen
- PROSE AG, Winterthur
- Carbo-Link, Fehraltorf
- Empa Laboratory Acoustics / Noise Control, Dübendorf
Mechanical modeling of concrete members strengthened and prestressed by a novel iron-based shape memory alloy reinforcement
Involved staff: Bernhard Schranz, Moslem Shahverdi, Christoph Czaderski
- SNSF (financing the project), Bern
- re-fer (material supply), Brunnen
- ETHZ, Zurich
Iron based Shape Memory Alloys as Shear Reinforcement for Civil Structures
Involved staff: Moslem Shahverdi, Christoph Czaderski, Julien Michels
- Swiss Innovation Agency - Innosuisse, financing
- re-fer (industrial partner), Brunnen
Investigation on the short-term and long-term behavior of the developed iron-based shape memory alloy at Empa
A cost-effective iron-based SMA (Fe-SMA) has been developed for application in civil engineering structures. The composition of the developed alloy is Fe–17Mn–5Si–10Cr–4Ni–1(V,C) (mass%). This Fe-SMA exhibits high tensile strength, excellent shape recovery stress (prestress force), and high elastic stiffness. Moreover, its material cost is low and it is easier to manufacture than nickel-titanium (NiTi) alloys. Recently, Fe-SMA strip and bars production has been started at an industrial scale. In this project, the experimentally determined properties of such industrially produced Fe-SMA strips and bars are investigated, and their recovery stress and recovery strain have been measured. The effects of prestraining and maximum heating temperature on the obtained recovery stress have been studied.
Involved staff: Moslem Shahverdi, Julien Michels, Christoph Czaderski, Matteo Breveglieri, Yajiao Yang
Project Partners: re-fer (financing and material supply), Brunnen
Thermo-mechanical modeling of the concrete elements structures by iron-based shape memory alloy elements
The development of new SMAs in the recent years, with the focus in research shifting to new Fe-Mn-Si SMAs, a significant cost reduction can be achieved and will help to broaden the application fields of SMAs.
An important step to extend the application range of the advanced material as iron-based shape memory alloys is having reliable simulation tools. A lot of work has already been done in this respect, but reliable tools to simulate the composite system (SMA bars/strips and the sub-structure) during activation of the SMA are still missing. The activation of iron-based shape memory alloy bars/strips is a process that incorporates four different physical processes: electrical current flow, heat propagation, continuum mechanics and martensitic phase transformation. In this project a macroscopic analysis of the interaction between the individual constituents of iron-base shape memory alloy bars/strips during the activation procedure is intended. While the sub-structures are modeled using elastic-plastic constitutive models, two different phenomenological material models are being employed for the SMAs. The proposed approaches succeed in reproducing experimental observations attributed to the SMA-concrete interaction.
Involved staff: Moslem Shahverdi and Paul-Remo Wagner (now PhD student at ETHZ)