162,376 research outputs found
Out-of-plane dynamic response of a tuff masonry wall. Shaking table testing and numerical simulation
The out-of-plane dynamic response of a masonry element is investigated, both experimentally and numerically. The results of shaking table tests on a tuff masonry wall, subjected to harmonic acceleration histories, are presented. An isotropic nonlocal damage-plastic model, accounting for the masonry strength-stiffness degrading and hysteresis mechanisms, is introduced in a finite element procedure to numerically describe the masonry structural response. A simplified scheme is analysed, where the wall is completely restrained at the base and free at the top. The measured top displacement history is compared with that numerically evaluated, obtaining a satisfactory agreement. Moreover, the effects of the onset and evolution of the degrading mechanisms in the masonry wall are highlighted
Compressive and shear behaviour of masonry panels: experimentation and numerical analysis
The compressive and shear behavior of masonry is here studied both experimental- ly and numerically. An experimental campaign has been carried out on 9 square-shaped one leaf masonry panels, reproducing historical masonry. Tests have been done for evaluating the elastic and shear moduli in both plane directions, with 6 panels rotated by 90 degrees, lead- ing to vertically aligned bed joints, and 3 panels maintained with horizontal bed joints. Com- pressive tests were executed on 6 masonry panels, 3 of them rotated by 90 degrees. Initial shear strength and shear modulus parallel to bed joints are evaluated through shear tests on 9 masonry triplets. Shear tests are performed on 3 rotated panels, applying an horizontal dis- tributed load, without vertical compression. Attention is paid to the service load state: only the initial phase of the tests is studied. Numerical models are proposed for representing actu- al masonry behavior, both discrete [1] and continuous [2,3], standard and micropolar, ob- tained by homogenization procedures [4]. Several numerical analyses are performed for simulating the experimental tests on masonry triplets and panels. The mechanical elastic pa- rameters of both discrete and continuous models are calibrated starting from laboratory data of masonry constituents and then by fitting the results of the initial phases of the experimental tests on masonry specimens
Numerical modelling of in-plane behaviour of adobe walls
Some tests for material characterization of adobe blocks and adobe masonry have been carried out in universities and laboratories around the world. However, the number of tests is quite limited in comparison with those carried out with other structural materials, such as masonry or reinforced concrete, and even those tests just refers to elastic properties. The results of adobe tests (i.e. compression strength, elasticity modulus, shear strength, etc.), as well as the results of cyclic and dynamic tests on adobe masonry components and small buildings show that the mechanical properties of adobe masonry and the seismic performance of adobe constructions highly depend on the type of soil used for the production of units and mortar. Basic properties, such as elasticity modulus, can have significant variation from one soil type to another.
The state-of-the-art for the numerical modelling of unreinforced masonry point to three main approaches: macro-modelling, simplified micro-modelling and detailed micro-modelling. In all three approaches, the use of elastic and inelastic parameters is required. For adobe masonry, the lack of knowledge concerning some of the material properties makes numerical modelling more difficult.
In the proposed work, the mechanical properties of the typical adobe masonry in Peru have been calibrated based on a cyclic in-plane test carried out on an adobe wall at the Catholic University of Peru (PUCP). The mechanical parameters calibration and the modelling results of the in-plane behaviour of the adobe wall are presented. Macro-modelling and simplified micro-modelling strategies are used in finite element software with an implicit solution strategy. The results of this work represent the first step for the numerical modelling of the seismic behaviour of adobe constructions
Numerical model to account for the influence of infill masonry on the RC structures behaviour
It is a common misconception considers that masonry infill walls in structural RC buildings can only increase the overall lateral load capacity, and, therefore, must always be considered beneficial to seismic performance. Recent earthquakes have showed numerous examples of severe damages or collapses of buildings caused by structural response modification induced by the non-structural masonry partitions.
From a state-of-the-art review of the available numerical models for the representation of the infill masonry behaviour in structural response, it was proposed an upgraded model. The proposed model is inspired on the equivalent bi-diagonal compression strut model, and considers the non-linear behaviour of the infill masonry subjected to cyclic loads. The model was implemented and calibrated in a non-linear dynamic computer code, VISUALANL.
In this paper, it is presented the proposed model and the results of the calibration analyses are briefly introduced and discussed
unreinforced masonry buildings
A recent earthquake of M=4.9 occurred on 29 October 2007 in C, ameli, Denizli, which is located in a seismically active region at southwest Anatolia, Turkey. It has caused extensive damages at unreinforced masonry buildings like many other cases observed in Turkey during other previous earthquakes. Most of the damaged structures were non-engineered, seismically deficient, unreinforced masonry buildings. This paper presents a site survey of these damaged buildings. In addition to typical masonry damages, some infrequent, event-specific damages were also observed. Reasons for the relatively wide spread damages considering the magnitude of the event are discussed in the paper
Brick and Concrete Masonry
Describes the various materials used in brick and concrete masonry construction: some of the more common masonry systems, and the details that go into making rna onry walls strong durable and weather-resistant
Multiscale computational first order homogenization of thick shells for the analysis of out-of-plane loaded masonry walls
This work presents a multiscale method based on computational homogenization for the analysis of general heterogeneous thick shell structures, with special focus on periodic brick-masonry walls. The proposed method is designed for the analysis of shells whose micro-structure is heterogeneous in the in-plane directions, but initially homogeneous in the shell-thickness direction, a structural topology that can be found in single-leaf brick masonry walls. Under this assumption, this work proposes an efficient homogenization scheme where both the macro-scale and the micro-scale are described by the same shell theory. The proposed method is then applied to the analysis of out-of-plane loaded brick-masonry walls, and compared to experimental and micro-modeling results.Peer ReviewedPostprint (author's final draft
The load bearing capacity of railway masonry arch bridges
This paper deals with the way of calculating
the load-bearing capacity of masonry arch railway
bridges. It reviews the basic aspects of structural behaviour
of these bridges, such as material non-linearity
of masonry and interaction with the soil. Paper shows,
how to include second order analysis in the calculation,
because in some cases it might have non-negligible influence.
It reminds the requirements of standards and
shows, how to calculate the load-bearing capacity in
accordance with these requirements with influence of
mentioned non-linearities
Homogenized model for herringbone bond masonry: linear elastic and limit analysis
A kinematic procedure to obtain in-plane elastic moduli and macroscopic masonry strength domains in the case of herringbone masonry is presented. The model is constituted by two central bricks interacting with their neighbors by means of either elastic or rigidplastic interfaces with friction, representing mortar joints. A sub-class of possible elementary deformations is a-priori chosen to describe joints cracking under in- plane loads. Suitable internal macroscopic actions are applied on the Representative Element of Volume REV and the power expended within the 3D bricks assemblage is equated to that expended in the macroscopic 2D Cauchy continuum. The elastic and limit analysis problem at a cell level are solved by means of a quadratic and linear programming approach, respectively. When dealing with the limit analysis approach, several computations are performed investigating the role played by (1) the direction of the load with respect to herringbone bond pattern inclination and (2) masonry textur
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