1,720,972 research outputs found
Characterization of Textile-Reinforced Mortar: State of the Art and Detail-Level Modeling with a Free Open-Source Finite-Element Code
Full text linkThe research addressed in the paper is aimed at calibrating a numerical model developed by using a free open-source finite-element code for the assessment of the structural performances of historical masonry buildings strengthened using the textile-reinforced mortar (TRM) technique. TRM is a near-surface-mounted system, which couples inorganic matrices with fiber-based textile or meshes. The main purpose is to develop a multiple-level numerical approach, starting with the detailed modeling of components and interfaces, followed by a computationally efficient intermediate level model, using layered elements, for the calibration of a lumped plasticity-based model suitable for the global analysis of structures. In this paper, the first research results are presented. In particular, a broad literature review concerning the mechanical characterization and analysis of TRM systems is collected. Then, the calibration of the numerical model, the validation through comparison with the results of experimental characterization tests available in the literature (tensile, shear bond, and in-plane shear tests) and a sensitivity analysis are reported. Nonlinear static analyses were performed, considering the nonlinearity of the composite material components and interfaces. The model was capable of accounting for the main parameters affecting the behavior of the composite material, such as the reinforcement ratio and orientation, the mortar characteristics and the wire–mortar interaction and proved to be a valid tool to investigate the optimization of TRM applicative details.
This work is made available under the terms of the Creative Commons Attribution 4.0 International license, https://creativecommons.org/licenses/by/4.0/.
Cite as: Boem, I. 2022. Characterization of Textile-Reinforced Mortar: State of the Art and Detail-Level Modeling with a Free Open-Source Finite-Element Code, Journal of Composites for Construction, 26 (5) 04022060. https://doi.org/10.1061/(ASCE)CC.1943-5614.0001240The project "conFiRMa" has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 10100341
Multi-layer modelling of masonry structures strengthened through textile-reinforced mortar [version 2; peer review: 1 approved]
Full text linkTextile-reinforced mortar (TRM) is an innovative strategy for the reduction of the seismic vulnerability of existing masonry buildings consisting in the application on the masonry surface, of a mortar coating with fiber-based grids or textiles embedded. The paper presents the calibration and application of a simplified modelling approach, based on multi-layered elements, for the simulation of existing masonry elements and structures strengthened through TRM.
The strengthened masonry is modelled by using 20-nodes brick elements formed by a stacking sequence of layers representing the different material components (the masonry, the mortar coating and the embedded reinforcement). The nonlinear behavior of the materials is considered and calibrated on the basis of experimental characterization tests on individual components available in the literature. The simplified assumption of perfect bond among layers is considered.
Non-linear static analyses are performed on samples of increasing complexity: elementary panels, structural elements (piers and spandrels) and a pilot building. The results of some tests on TRM strengthened masonry, available in the literature, are considered to assess the model reliability in terms of capacity curves and collapse mode. The model is capable of detecting the typical failure mechanism of existing masonry, namely the diagonal cracking, the in-plane bending and the out-of-plane bending and is able to detect the activation also of mixed failure modes, that often occur in actual configurations.
Given the coarse mesh size and the smear plasticization assumption, the model is not suitable for the rigorous reproduction of individual cracks but represents a good compromise between the goal to grasp the structural performances at the wide scale, including failure modes, and the analysis optimization.
This work is made available under the terms of the Creative Commons Attribution 4.0 International license, https://creativecommons.org/licenses/by/4.0/.
Cite as: Boem, I. 2022. Multi-layer modelling of masonry structures strengthened through textile-reinforced mortar [version 2;
peer review: 1 approved]. Open Res Europe 2023, 2:132. https://doi.org/10.12688/openreseurope.15233.2)The project "conFiRMa" has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 10100341
Masonry elements strengthened through Textile-Reinforced Mortar: application of detailed level modelling with a free open-source Finite-Element code
Full text linkThe paper concerns the modelling of masonry elements strengthened through Textile Reinforced Mortar (TRM), a near surface system made of fiber-based grids or textiles embedded in mortar layers. Recently, the author, focusing on the mechanical characterization of TRM composites, developed a detailed level modelling approach by using the free, open-source Finite-Element code OOFEM, for the simulation of experimental tests on TRM coupons (pull-out tests, tensile tests, shear bond tests and in-plane shear tests). The model was capable to account for the failure of single components (e.g. the fibers tensile failure, the mortar cracking and crushing), as well as of their interactions (the debonding of the fibers from the mortar and of the mortar from the masonry substrate). In this paper, the detailed-level modelling approach is applied to the simulation of TRM strengthened masonry elements subjected to diagonal compression, in-plane and out-of-plane bending tests, investigating on the typical failure modes of masonry. Non-linear static analyses are performed, with nonlinearities of materials and interfaces deduced from experimental evidences. The comparison with some experimental results and a parametric study allowed to evidence the reliability of the models and their sensitivity to the main components characteristics
Masonry Elements Strengthened with TRM: A Review of Experimental, Design and Numerical Methods
Full text linkTextile-Reinforced Mortar (TRM) is a modern and compatible strengthening strategy for existing masonry, which consists in plastering the walls by means of mortar layers with embedded grids or textiles made of long fibers. TRM can be very useful for the reduction of the seismic vulnerability of masonry buildings, since the fiber-based reinforcement, carrying high tensile stresses, opposes the widening of cracks and provides “pseudo-ductility” to the masonry. The increasing number of available studies on the subject testifies to its relevance but also the lack of a standardized or well-establish approach to quantify the benefits of these systems on the performance of masonry. The present review is aimed at providing a broad overview of how the study of TRM-strengthened masonry elements has been addressed in the literature. In particular, the main features of the different experimental tests are compared, dealing with both in-plane and out-of-plane behavior. Moreover, the different design methods and numerical modeling strategies are presented and discussed
Rinforzo di murature esistenti mediante intonaco armato con rete in GFRP
No full textNel presente articolo sono illustrati i risultati di una campagna sperimentale eseguita su campioni di muratura per
valutare l'efficacia di una tecnica di rinforzo basata sull’applicazione di un intonaco armato con rete in materiale
composito di fibre di vetro in matrice polimerica GFRP (glass fiber reinforced polymer). In particolare, si fa
riferimento a prove di compressione diagonale in modo da verificare l’efficacia del rinforzo a taglio. Sono prese in
considerazione tre diverse tipologie di muratura (in mattoni a due teste, in pietra con spessore 400 mm e in ciottoli
con spessore 400 mm) e tre differenti tipologie di malta per l’intonaco (malta di calce, malta bastarda e malta di
calce e pozzolana). Prove di compressione centrata su pannelli non rinforzati sono state condotte per determinarne
la resistenza a compressione ed il modulo elastico. Sono riportati, inoltre, gli esiti di indagini sperimentali condotte
per verificare l’aderenza della rete GFRP all’intonaco (pull-out) e l’efficacia della giunzione per sovrapposizione
tra reti (lap-splice), confrontando i risultati di due diversi metodi di prova (su campioni a cilindro e a lastra)
Numerical Study on the Performance and Failure Modes of Bolted Connections in Pultruded-Fibre-Reinforced Polymer (PFRP) Profiles
Full text linkThe use of pultruded-fibre-reinforced polymer (PFRP) composite profiles in structural applications is rapidly increasing, due to their high strength-to-weight ratio, corrosion resistance, and durability. Bolted joints between PFRP play a critical role, as localized high stresses in a material that typically exhibits brittle behaviour—especially in tension and shear—can lead to sudden failure. This study aims to investigate the mechanical performance of such bolted connections (in terms of stiffness, strength, displacement capacities and failure modes), contributing to the development of reliable yet optimized design criteria for structural applications. In particular, numerical analyses of single-bolted connections in PFRP profiles are presented in the paper. To emphasize the general validity of the model and demonstrate its applicability across different configurations, the simulations were validated against experimental results from three separate test campaigns, which varied in both material (three different PFRP composites) and geometry (profile thickness, bolt diameter, and hole–end distance). Finite element models using continuum shell elements in ABAQUS, based on the Hashin failure criteria, successfully captured typical failure modes, including shear-out and pin-bearing. Two analysis approaches—implicit and explicit solvers—were also compared and discussed. Sensitivity analyses were carried out to enhance the model’s accuracy and its computational efficiency. The validated model was then extended to simulate different configurations, investigating the role of the main parameters influencing the connections
Dynamic identification of a stone masonry building: influence of damage and of CRM retrofitting
No full textThe dynamic identification of a full-scale, two-storey building, made of rubble stone masonry, was achieved. Different configurations were analyzed: unstrengthened masonry and retrofitted masonry, in both undamaged and damaged conditions. Damage was accomplished by testing the building under lateral cyclic loading, to reproduce the seismic effects. The strengthening technique (CRM – Composite Reinforced Mortar) consisted in plastering the outer facades by means of a 30 mm tick mortar coating reinforced with glass-fiber polymer meshes and in introducing transversal connectors injected in the masonry. The mode shapes and natural vibrating frequencies were analyzed and compared, evidencing the effects of damage and of retrofitting. A finite element numerical model was developed, to perform eigenvalue analysis and calibrate the equivalent masonry stiffness for the different configurations
Sperimentazioni su murature faccia vista rinforzate con reticolo di trefoli metallici inseriti nei giunti di malta e intonaco con rete in GFRP
No full textNumerical Simulations of Masonry Elements Strengthened Through Fibre-Reinforced Mortar: Detailed Level Modelling Using the OOFEM Code
Full text linkA detailed level numerical model for Fibre Reinforced Mortar (FRM) using the free, open source code OOFEM has been recently calibrated and validated by the authors through comparison with experimental characterization tests (i.e. pull-off tests, tensile tests and shear bond tests). In this
paper, the developed model is adopted to perform numerical simulations on FRM strengthened masonry elements. In particular, out-of-plane and in-plane bending tests and in-plane diagonalcompression tests are simulated by adopting the same modelling hypostasis and characteristics and
the results are compared with experimental tests available in the literature. Both the masonry and the mortar are modeled through solid elements, the yarns of the fibre-based mesh with truss elements and the interactions among the components (yarns, mortar, masonry) by means of interface elements. Non-linear static analyses are performed, considering the materials and interfaces non-linearity. The simulations result capable to realistically reproduce the typical performances of masonry elements in terms of global performances and damage pattern and permit to investigate on the resisting mechanisms and on the interactions between the components
Cyclic tests on two-leaf rubble stone masonry spandrels strengthened with CRM coating on one or both sides
Full text linkThe paper reports the results of an original experimental campaign carried out on full-scale, two-leaf rubble stone masonry spandrels retrofitted using the Composites Reinforced Mortar (CRM) technique, applied on one or both wall faces. The CRM system consisted of a mortar coating reinforced with Glass Fibre-Reinforced Polymer (GFRP) meshes and GFRP transverse connectors to promote the connection with the existing masonry. When the coating was applied on one side, additional transverse connectors, made of grout cores with embedded steel ties (artificial diatons), were also used. These elements further strengthened the connection between the coating and the masonry and connected the leaves of the multi-leaf stone masonry walls. The GFRP mesh in the mortar coating provided the walls with the capacity to resist tension: once the coating and the masonry cracked, the strengthened samples withstood higher distortions, exhibited increased ductility and developed very diffuse crack patterns before collapsing, yielding greater energy dissipation. Furthermore, the transverse connectors enabled the composite action of the CRM coating and the walls and, in the case of artificial diatons, prevented the separation of the masonry leaves. The resistance of the walls with the CRM coating on one and both sides was 2.8 and 3.4 times that of the plain samples, respectively; in both cases, the ultimate drift was more than five times larger than the reference, while the cumulative dissipated energy was more than 30 times. The equivalent hysteretic damping in the damaged state was 11–14% (for CRM on one side) and 8–9% (for both sides)
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