Search results for " masonry"
showing 10 items of 76 documents
Cyclic response of masonry infilled RC frames: Experimental results and simplified modeling
2014
The recent large interest in nonlinear seismic analysis methods, static and dynamic, has required proper strategies of modeling based on reliable, and at the same time easy to use, constitutive laws for the structural elements. Regarding the behavior of framed structures, special attention has to be devoted to infills because of the key role they play in modifying overall stiffness, strength and ductility under seismic excitation. Pointing out the attention on this topic the paper discusses a criteria for modeling the structural behavior of infills based on a macromodeling approach, that is to say on the substitution of infills with diagonal pin jointed struts. Is here shown how multilinear…
CH of masonry materials via meshless meso-modeling
2014
In the present study a multi-scale computational strategy for the analysis of masonry structures is presented. The structural macroscopic behaviour is obtained making use of the Computational Homogenization (CH) technique based on the solution of the boundary value problem (BVP) of a detailed Unit Cell (UC) chosen at the meso-scale and representative of the heterogeneous material. The smallest UC is composed by a brick and half of its surrounding joints, the former assumed to behave elastically while the latter considered with an elastoplastic softening response. The governing equations at the macroscopic level are formulated in the framework of finite element method while the Meshless Meth…
Mesoscopic aspects of the computational homogenization with meshless modeling for masonry material
2020
The multiscale homogenization scheme is becoming a diffused tool for the analysis of heterogeneous materials as masonry since it allows dealing with the complexity of formulating closed-form constitutive laws by retrieving the material response from the solution of a unit cell (UC) boundary value problem (BVP). The robustness of multiscale simulations depends on the robustness of the nested macroscopic and mesoscopic models. In this study, specific attention is paid to the meshless solution of the UC BVP under plane stress conditions, comparing performances related to the application of linear displacement or periodic boundary conditions (BCs). The effect of the geometry of the UC is also i…
Nonlinear FE analysis of out-of-plane behaviour of masonry walls with and without CFRP reinforcement
2014
Abstract The out-of-plane behaviour of unreinforced and CFRP reinforced masonry wall is studied by means of experimental investigation and numerical FE modelling. The latter is based on a linear constitutive law both for ashlars and mortar joints constituting masonry and the lines of potential delamination are taken into account by means of an interface element with bi-linear law, reproducing the opening failure mode. When reinforcement is introduced, an interface element with bi-linear law is also used, reproducing sliding failure mode. Comparison between numerical and experimental results show the reliability of the modelling. Moreover, a parametric analysis is carried out in order to inv…
Numerical modelling of out-of-plane response of infilled frames: State of the art and future challenges for the equivalent strut macromodels
2017
Abstract Infill-frame interaction constitutes a still open question both in research and in practicing engineering. Computational models used to predict this interaction are, in most cases, addressing the estimation of the response of the infilled frames when subjected to actions parallel to their plane. However, the observation of the post-earthquake damage has demonstrated that infills, weakened by the in-plane actions, may fail out-of-plane increasing the risks associated to the earthquake scenarios. In spite of this, different studies have shown that infills, if properly designed and supported by the frame, exhibit a significant strength and displacement capacity when called to resist t…
IP-OOP interaction in URM infilled frame structures: A new macro-modelling proposal
2020
Abstract Reinforced concrete frame structures with unreinforced masonry (URM) infills represent a common construction practice all over the world. To correctly assess the seismic performance of these structures, prediction of the behaviour of masonry infills under in-plane (IP) and out-of-plane (OOP) loading, as well as their interaction, is of primary importance. Different approaches are available in the literature with different levels of approximation for assessment of the IP-OOP infill response, showing increasing interest in this field. In this context, this paper presents a new macro-element model which can simulate the behaviour of URM infill walls under seismic IP and OOP actions. T…
Out-of-plane behaviour of unreinforced masonry infill walls: Review of the experimental studies and analysis of the influencing parameters
2021
Abstract Over the last 50 years, research has mainly focused on characterizing the In-Plane behaviour of unreinforced masonry infill walls. Recently, the focus of research has been addressed to understanding Out-of-Plane behaviour, also from the experimental point of view. However, in the experimental campaigns, there is high variability in the geometrical and mechanical properties of URM infill walls and also in the application of Out-of-Plane loads. Therefore, it is important to outline and critically evaluate the major findings obtained by experimental studies and identify research gaps to better understand the differences and the affinity of apparently equivalent tests. In this paper, t…
Parameters affecting the fundamental period of infilled RC frame structures
2015
Despite the fact that the fundamental period appears to be one of the most critical parameters for the seismic design of structures according to the modal superposition method, the so far available in the literature proposals for its estimation are often conflicting with each other making their use uncertain. Furthermore, the majority of these proposals do not take into account the presence of infills walls into the structure despite the fact that infill walls increase the stiffness and mass of structure leading to significant changes in the fundamental period numerical value. Toward this end, this paper presents a detailed and in-depth analytical investigation on the parameters that affect…
Indagini Diagnostiche nell'Ex Chiesa Madre di Santa Margherita di Belice
2010
La relazione presenta in modo dettagliato gli esiti di una campagna d'indagini diagnostiche non distruttive e minimamente invasive svolte nella ex chiesa madre di Santa Margherita di Belice per supportare, in particolare, lo studio delle murature e della decorazione a stucco. Le indagini hanno supportato l'elaborazione del progetto definitivo e del progetto esecutivo del restauro, come prescritto dalla normativa di riferimento. The report presents in detail the results of a campaign of non-destructive and minimally invasive diagnostic surveys performed in the former mother church of Santa Margherita di Belice to support, in particular, the study of masonry and stucco decoration. The investi…
A macro-modelling approach for the analysis of infilled frame structures considering the effects of openings and vertical loads
2015
During the last decades, several macro-models have been proposed for the modelling of the infill panels' contribution to the lateral strength of frames. Despite all this effort, a robust model, which takes into account the influence of the vertical load, is not yet available. Furthermore, the influence of the very common case of infill walls with openings, such as windows and doors, has been neglected in all the code provisions that have been published so far. In this paper, an updated macro-model, based on the equivalent pin-jointed diagonal compressive strut, is presented. The proposed macro-model is able to represent the stiffening effect of the infill panel with openings by taking into …