The concerted research between M2i, TNOand the Holst Centre aims at developing the technology for modular ultra lightand ultra thin, flexible, easy-to-wear electronic products such as lighting andsignage devices, reusable and disposable sensor devices, deformable solarpanels and displays. An important aspect of this program is to gain knowledgeabout the mechanical behavior, reliability and durability of these flexibledevices during production and during actual usage. The scientific aim of the project is todevelop tools that enable to understand and predict the life-time of multilayerlaminates taking into account the effect of visco-elastic and/or plasticmaterial behavior during cyclic loading and the environment, in particular relativehumidity, on the development of the mechanical damage. The tools to bedeveloped comprise suitable experimental methods to impose a knownstress/strain state on a chosen multilayer material and to understand theunderlying physical mechanisms. The location is TU Eindhoven.
End procedure:31 January 2010
Glue mortars are used for joiningbuilding materials, e.g. tiles on concrete surfaces. Open time of glue mortarscan be defined as the time in which joining these materials can be achievedwithout a decrease in performance of the joint. The open time will affect therate of application of the tiles and also the final adhesion. Therefore,considerable effort is undertaken by product manufactures to improve the opentime. TNO has worked together with several industrial partners on this topic. However,the exact processes that determine the open time of glue mortars are unclear.To efficiently improve the products knowledge of the processes that determinethe open time and adhesive force is important. Several processes can determinethe open time: chemical reactions (carbonation), water content, watertransport, concentration and transport of additive materials. In this projectthe aim is to measure and model these processes and relate them to the opentime. One of the techniques that will be applied to investigate the transportprocesses is nuclear magnetic resonance (NMR) imaging. With NMR nuclei such asH, F, P, Na can be measured. With NMR it is feasible to measure transportprocesses, chemical changes, pore size distribution and possibly also the flowof additive materials. Next to NMR other measurement techniques will be appliedto investigate chemical and structure changes, such as: optical imageprofiling, SEM, FT-IR, TGA, etc.
PhD researcher on estimation of structure lifetime at M2i
Many structures in civil engineering andin transport such as bridges, trains, ships, and lorries are cyclically loaded.This often results in fatigue cracks which determines the lifetime of thesestructures. State of the art is safe life design which has a number ofdisadvantages among others its conservative estimation of the lifetime of astructure based on test results of standard details. A much better approach is obtained based on damage modelling which is thesubject of this project. Both for new designs as well as for existing structures with this approach,based on crack initiation and crack growth of the metal involved, a much moreprecise estimation of the lifetime is obtained. To arrive at this goal initiation and propagation of cracks will be integratedin a design model. Except for numerical research also experimental research will be carried out toverify the numerical results as well as to validate the design model. The research will be carried out both atTU/e (structural design group of Prof. Soetens) and at TNO (NetherlandsOrganisation for Applied Scientific Research, research carried out for Dutchand international companies and governmental organisations) in
End procedure:31 January 2010
Metal-polymer laminates of electrolyticchromium coated steel plate (ECCS) are increasingly used for packaging of foodand beverages. From a materials point-of-view there are a number of challengessince the polymer coated sheet is subjected to severe loading conditions duringforming, e.g. deep-drawing and redrawing (DRD) and wall ironing (DWI). Damageis introduced during production, but also during the subsequent contentsterilization procedure and it is obvious that this damage may become apparentduring the prolonged shelf-life of the product. The main objective of thisproject is to improve product reliability using insight in micro-scaledeformation mechanisms at the polymer-steel interface and the interplay betweenmicro-deformation and de-adhesion. The microstructural evolution near theinterface and its interrelation with the evolution of the interface geometryand interface bonding is key to understand and model the behaviour of thelaminates. This project aims to clarify the microscopic processes thatdetermine polymer-metal adhesion during forming. Deformation and delaminationprocesses on multiple scales will be studied numerically and experimentally. Tothis purpose, the evolution of the interface structure which is related to bothsubstrate roughening and coating deformation, will be investigated. The projectis organized in two workpackages. Workpackage A concentrates on the small-scaleexperimental work that will be carried out in
End procedure: 31 January 2010
Info about PhD vacancy in Netherland: http://www.academictransfer.com/