TY - JOUR A1 - Guerra, E. S. S. A1 - Silva, B. L. A1 - Melo, J. D. D. A1 - Kalinka, Gerhard A1 - Barbosa, A. P. C. T1 - Microscale evaluation of epoxy matrix composites containing thermoplastic healing agent N2 - Among the strategies to produce healable thermosetting systems is their modification by the addition of thermoplastic particles. This work investigates the influence of poly(ethylene-co-methacrylic acid) (EMAA) on fibermatrix interfacial properties of a glass fiber reinforced epoxy matrix composite. Epoxy-EMAA interactions were evaluated using differential scanning calorimetry (DSC) and infrared spectroscopy. The effects of EMAA on the epoxy network formation were evidenced by changes in glass transition temperature, cure kinetics and alteration of chemical groups during cure. Interfacial shear strength (IFSS) measurements obtained by single fiber pull-out tests indicate similar interfacial properties for pure and EMAA modified epoxy. Additionally, the potential for self-healing ability of an EMAA modified epoxy was demonstrated. However, IFSS after a healing cycle for the EMAA modified epoxy was lower as compared to the pure epoxy, because of the lower fiber-EMAA interfacial shear strength. So, thermoplastic healing agents has not only to fill cracks in the matrix material, but also have to be optimized regarding its interface properties to the reinforcing fibers. KW - Interfacial strength KW - Fiber/matrix bond KW - Self-healing KW - Polymer-matrix composites (PMC) PY - 2022 DO - https://doi.org/10.1016/j.compscitech.2022.109843 SN - 0266-3538 VL - 232 SP - 1 EP - 9 PB - Elsevier Ltd. CY - Niederlande AN - OPUS4-56379 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Miccoli, Lorenzo A1 - Müller, U. A1 - Silva, B. A1 - Da Porto, F. A1 - Hracov, S. A1 - Pospisil, S. A1 - Adami, C.-E. A1 - Vintzileou, E. A1 - Vasconcelos, G. A1 - Poletti, E. ED - Jasienko, J. T1 - Overview of different strengthening techniques applied on walls used in historical structures N2 - Different types of vertical elements, such as masonry, massive walls and timber frame elements, exhibit a different response exposed to the same loading scenario, in particular when it concerns dynamic loading. It is therefore paramount to investigate the principal response of different types of construction with different materials under a variety of loading scenarios. From there, the design of strengthening techniques against earthquakes can be performed. This paper presents the results from experiments, where various retrofitting techniques were tested. The goals were to define and improve laboratory procedures for evaluating the intervention technologies and specifications for laboratory specimens. From this base tests to characterise the experimental behaviour of original and strengthened masonry walls were performed, in order to obtain information on the system performance and the main constitutive laws relevant for modelling. The test campaigns were focused on static tests as well as cyclic tests of unreinforced and reinforced vertical building elements. The study is part of our work in the framework of the ongoing project NIKER funded by the European Commission dealing with improving immovable Cultural Heritage assets against the risk of earthquakes. T2 - SAHC 2012 - 8th International conference on structural analysis of historical constructions CY - Wroclaw, Poland DA - 15.10.2012 KW - Stone masonry KW - Brick masonry KW - Earthen materials KW - Half timbered walls KW - Grouting PY - 2012 SN - 978-83-7125-216-7 SN - 0860-2395 VL - 3 SP - 2870 EP - 2878 PB - DWE CY - Wroclaw, Poland AN - OPUS4-27275 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Darvishi Kamachali, Reza A1 - da Silva, A. A1 - McEniry, E. A1 - Gault, B. A1 - Neugebauer, J. A1 - Raabe, D. T1 - Segregation-assisted spinodal and transient spinodal phase separation at grain boundaries N2 - Segregation to grain boundaries affects their cohesion, corrosion, and embrittlement and plays a critical role in heterogeneous nucleation. In order to quantitatively study segregation and low-dimensional phase separation at grain boundaries, here, we apply a density-based phase-field model. The current model describes the grain-boundary thermodynamic properties based on available bulk thermodynamic data, while the grain-boundary-density profile is obtained using atomistic simulations. To benchmark the performance of the model, Mn grain-boundary segregation in the Fe–Mn system is studied. 3D simulation results are compared against atom probe tomography measurements conducted for three alloy compositions. We show that a continuous increase in the alloy composition results in a discontinuous jump in the segregation isotherm. The jump corresponds to a spinodal Phase separation at grain boundary. For alloy compositions above the jump, we reveal an interfacial transient spinodal phase separation. The transient spinodal phenomenon opens opportunities for knowledge-based microstructure design through the chemical manipulation of grain boundaries. The proposed density-based model provides a powerful tool to study thermodynamics and kinetics of segregation and phase changes at grain boundaries. KW - Grain Boundary Spinodal KW - Densty-based Thermodynamics KW - Microstrucrue Design PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-519497 DO - https://doi.org/10.1038/s41524-020-00456-7 VL - 6 IS - 1 SP - 191 PB - Nature AN - OPUS4-51949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -