Academic literature on the topic 'Masonry panel subjected to in-plane loading'

Framed masonry panels are subjected to both in-plane and out-of-plane loading during earthquakes and their load-carrying capacity in the out-of-plane direction after being damaged is crucial for overall stability and safety. To assess the effect of in-plane damage on their out-of-plane behavior, three half-scaled clay brick framed masonry panels were subjected to a sequence of slow cyclic in-plane drifts and shake table-generated out-of-plane ground motions. The framed panels maintained structural integrity and out-of-plane stability even when severely damaged. Also, failure of specimens was primarily due to excessive out-of-plane deflection, rather than amplified inertia forces. Weaker interior grid elements divided masonry in smaller subpanels, and helped delay failure by controlling out-of-plane deflection and significantly enhancing the in-plane response. This subpaneling also greatly improved the in-plane response and energy dissipation potential, and consequently, the out-of-plane failure of the masonry was delayed and large in-plane drifts of up to 2.2% could be safely sustained.

Abstract Partition walls are often made of masonry in Romania. Although they are usually considered non-structural elements in the case of reinforced concrete framed structures, the infill panels contribute significantly to the seismic behaviour of the building. Their impact is difficult to assess, mainly because the interaction between the bounding frame and the infill is an intricate issue. This paper analyses the structural behaviour of a masonry infilled reinforced concrete frame system subjected to in - plane loading. Three numerical models are proposed and their results are compared in terms of stiffness and strength of the structure. The role of the openings in the infill panel on the behaviour is analysed and discussed. The effect of gaps between the frame and the infill on the structural behaviour is also investigated. Comparisons are made with the in-force Romanian and European regulations provisions.

Unreinforced masonry walls are prone to failure when subjected to out-of-plane loading. This is due to their low performance in bending, and often the lack of appropriate connection to returning walls and floors. This paper investigates the possibility to use oriented strand boards (OSB) panels to improve the out-of-plane performance of brick masonry walls. The proposed technique considers securing OSB type-3 panels behind masonry walls with chemical and mechanical connections. The work presents finite element models to predict their behaviour. The models have been calibrated and validated through a three-phase experimental campaign, aimed at (a) characterizing the main structural components, (b) studying the out-of-plane behaviour of small-scale masonry prisms and (c) studying the behaviour of 1115 × 1115 × 215 mm masonry walls. The finite element models developed are based on a micromodel technique developed in ABAQUS and demonstrated to adequately capture the behaviour of both plain and retrofitted models to the ultimate load. The models also show an excellent correlation of the compressive damage and tensile damage with the experimental failure pattern. Generally, the model predicted the peak load and the corresponding failure and toughness to within less than 10% of the average test results.

This paper proposed a method for predicting failure loads of masonry wall panels subject to uniformly distributed lateral loading based on a concept of structural stress state. Firstly, the characteristics of the structural stress state of masonry wall panels subjected to uniform distributed lateral loading were investigated through experimental results. Then, a new parameter was proposed to characterize the structural stress state. Next, the relation of the failure loads between a specified base wall panels and other wall panel was established using the proposed parameter. In this way, a method (called a ST method) based on a structural stress state parameter to predict the failure load of masonry wall panel from the base wall panel was established. The following case studies validated the ST method by comparing the predicted failure load with the experimental results, as well as those predicted from the existing yield line theory (YLT), the FEA method and the GSED-based cellular automata (CA) method. The ST method provided an innovative way of structural analysis on the basis of structural stress state.

Today, there are several computational models to predict the mechanical behaviour of masonry structures subjected to external loading. Such models require the input of material parameters to describe the mechanical behaviour and strength of masonry constructions. Although such masonry material parameters are characterised by stochastic-probabilistic nature, engineers are assigning the same material properties throughout the structure to be analysed. The aim of this paper is to propose a methodology which considers material spatial variability and stochastic strength prediction for masonry structures. The methodology is illustrated on a case study covering the in-plane behaviour of a low bond strength masonry wall panel containing an opening. A 2D non-linear computational model based on the Discrete Element Method (DEM) is used. The computational results are compared against those obtained from the experimental findings in terms of failure mode and structural capacity. It is shown that computational models which consider the spatial variability of masonry material properties better predict the load carrying capacity, stiffness and failure mode of the masonry structures. These observations provide new insights into structural behaviour of masonry constructions and lead to suggestions for improving assessment techniques for masonry structures.

Taking into consideration the seismic vulnerability of older buildings and the increasing need for reducing their carbon footprint and energy consumption, the application of an innovative system is investigated; the system is based on the use of textile-reinforced mortar (TRM) and thermal insulation as a means of combined seismic and energy retrofitting of existing masonry walls. Medium-scale tests were carried out on masonry walls subjected to out-of-plane cyclic loading. The following parameters were investigated experimentally: placement of the TRM in a sandwich form (over and under the insulation) or outside the insulation, one-sided or two-sided TRM jacketing and/or insulation, and the displacement amplitude of the loading cycles. A simple analytical method is developed and found in good agreement with the test results. Additionally, numerical modeling is carried out and also found in good agreement with the test results. From the results obtained in this study, the authors believe that TRM jacketing may be combined effectively with thermal insulation, increasing the overall strength and energy efficiency of the masonry panels in buildings.

This paper presents the results of an experimental program investigating the behavior of a steel frame with masonry infill panels subjected to cyclic loadings. Three types of masonry frequently used were tested. Loads were high enough to crack the infill panels without yielding the steel frame. The effects of the infill panels on the stiffness and the energy dissipation of the structure were evaluated. From the experimental results obtained on the three types of masonry, models are proposed to evaluate the behavior of a structure with infill panels. These models could be used in nonlinear dynamic analysis. Key words: masonry infills, masonry, seismic behavior, cyclic loading, modelling, frames.

Design rules are proposed for assessing the bearing strengths of hollow concrete masonry walls subjected to in-plane concentrated loads. These are derived from numerical and experimental studies of this problem. Two possible zones of failure are considered: the solid–grouted masonry directly beneath the concentrated loads, and the hollow masonry beneath the grouted portion. The important factors influencing the bearing strength are taken into account: loading eccentricity across the wall width, effective loading area, loading plate length, and loading location along the wall. An angle of 22° or slope (vertical to horizontal) of 2.5:1 is chosen for a safe estimate of the dispersion of concentrated load through the solid–grouted masonry. For partial grouting patterns, at least two courses downward should be grouted to a length compatible with the loading plate. When compared with the available numerical and experimental results, conservative estimates of ultimate strength are obtained in all cases.Key words: design rules, hollow concrete masonry wall, in-plane concentrated load, out-of-plane eccentricities, loading plate length, loading locations, dispersion angle.

The ability of mortarless wall to restrain/sustain lateral load become important aspect to be consider in the design of wall. Therefore, this paper presents analyses of mortarless wall subjected to in-plane combined loading using finite element programs. The developed 2D finite element program is used in this research. The finite element models are developed based on micro modelling approach where each constituent of masonry (block and dry joint) connected each other by joints at their actual position. Eight nodded isoparametric plane element and six nodded zero thickness isoparametric interface element are used to represent block unit and dry joint respectively. The developed models are analysed under nonlinear environment. The most relevant results concern the strength response of the dry joint masonry walls subjected to in-plane combined compressive and shear loading. The results of finite element analysis compared with corresponding experimental results and its show good agreement. Parametric study also performed to consider the important parameters that effect the design of wall under combined loading. Significant features of the structural behaviour, ultimate capacity and observed failure mechanisms are addressed and discussed.

Predicting the strength of masonry panel is the primary concern to have enough resistance for severe an extreme seismic event. Hence, there are numerous design codes available for the estimation of the force capacity of masonry panel. What is yet unclear is that evaluation of the effectiveness of the design code to estimate the strength of wall and identification of critical role of parameters. Further investigation is required to assess the objectives and it is carried out by DIC analysis and numerical study. This paper proposes a new approach to determine the diagonal tensile strength of masonry panel by DIC analysis and offers the guideline to estimate diagonal tensile strength by numerical study. These findings contribute in more accurate ways of predicting the diagonal tensile strength and this assessment give better understanding of stress field of the masonry panel to engineers and researchers. Another outcome is that the estimated diagonal tensile strength plays a significant role of shear force capacity as proposed by Turnšek and Čačovič so the more significant findings to emerge from this study is that it offers to predict diagonal tensile, shear strength of masonry panel.
Thesis (MPhil) -- University of Adelaide, School of Civil, Environmental and Mining Engineering, 2019

Research Doctorate - Doctor of Philosophy (PhD)
This thesis presents a comprehensive, macroscopic material model for the in-plane behaviour of brick masonry and describes its incorporation into an incremental, non-linear finite element computer model capable of simulating the behaviour of masonry at all levels of applied load. The material model is derived from a large number of biaxial tests on half scale brick masonry panels and consists of elastic and in-elastic deformation characteristics and a failure criterion. In the elastic range, the brick masonry behaves, on average, isotropically. However, its in-elastic stress-strain relations and failure criterion are significantly influenced by the presence of mortar joints acting as planes of weakness. The material model allows the brick masonry to be modelled as a continuum. Despite the fact that the influence of individual bricks and joints is averaged , depending on the state of stress , the failure can occur in the joints alone, in a combined mechanism involving both brick and joint or by crushing and s palling of the masonry. The results of the finite element model have been verified by comparing the results of racking and vertical load tests on steel frames with brick masonry infill. Infilled frames of varying height/length ratio and frame/wall stiffness and infill panels of differing curing history (and hence differing strength) have been considered. Sensitivity analyses of the parameters of the material model have been carried out with reference to racking tests on infilled frames. The modulus of elasticity and the strength parameters were found to be the most significant properties of masonry. The model has also been used to carry out a study of infilled frame and shear wall behaviour. In both cases various geometries and relative strength parameters have been used and their significance on the strength of walls investigated. These studies illustrate the potential of the model as both a research tool and as an aid to design.

An experimental program was conducted to investigate some aspects of in-plane behaviour of masonry infilled steel frames. Eight concrete masonry infilled steel frames, consisting of three fully grouted and five partially grouted infills, were tested under combined lateral and axial loading. All specimens were constructed using one-third scale concrete masonry units. The in-plane lateral load was gradually increased at the frame top beam level until the failure of the specimen while an axial load was applied to the top beam and held constant. The parameters of the study included axial load, extent of grouting, opening, and aspect ratio of the infill. The experimental results were used, along with other test results from the literature, to evaluate the efficacy of stiffness and strength predictions by some theoretical methods with a focus on Canadian and American design codes. Cracking pattern, stiffness, failure mode, crack strength, and ultimate strength of the specimens were monitored and reported. Presence of axial load was found to increase the ultimate strength of the infilled frame but had no marked effect on its stiffness. Two specimens exhibited “splitting failure” due to axial load. Partially grouted specimens developed extensive diagonal cracking prior to failure whereas fully grouted specimens showed little or no cracking prior to failure. An increase in grouting increased the ultimate strength of the frame system but reduced its ductility. Presence of opening reduced the ultimate strength of the infilled frame and increased its ductility but its effect on the stiffness of the frame system was not significant. A review of current Canadian and American design codes showed that the Canadian code significantly overestimates the stiffness of infilled frames whereas the American code provides improved predictions for stiffness of these frame systems. Both design codes underestimate the strength of masonry infilled steel frames but grossly overestimate the strength of masonry infilled RC frames.
Masonry infilled steel frames tested under combined axial and lateral loading. Behaviour as affected by axial load, grouting, aspect ratio and openings discussed. Correlation between axial load level and the infill lateral resistance examined. Efficacy of the Canadian and American masonry standards on infill design was examined.

Tese de doutoramento em Engenharia Civil (ramo do conhecimento Estruturas)
Masonry walls consist of the main elements responsible for the global stability of masonry buildings when subjected to lateral loads such as wind and seismic forces. These elements are subjected to gravity forces, bending moments and shear forces due to the horizontal loading. The masonry beams above the openings are important structural elements promoting the coupling behaviour of the masonry piers enabling the transfer of forces between them. Besides, the consideration of these elements leads to higher stiffness of the building. The anisotropic behaviour added to bi-axial stress state generated by the combination of those efforts becomes the behaviour of masonry walls and beams very complex. Therefore, this research aims at better understanding the behaviour of masonry walls and beams subjected to in-plane loading and propose analytical methodology for their design. Based on the literature review, an extensive experimental program is planned, being composed by experimental tests for the characterization of mechanical behaviour of masonry and masonry materials, in-plane cyclic tests on masonry walls and tests on masonry beams under flexure and shear. Based on experimental results, calibration of numerical micro-model using software DIANA® is presented. Moreover, a parametric analysis of masonry walls and beams is performed in order to assess the influence of different boundary conditions, aspect ratios, loading and reinforcement arrangements that could not by studied in experimental program. Results indicates that masonry walls and beams are described by similar flexural and shear resisting mechanisms. Unreinforced walls and beams present a very brittle behaviour. On the other hand, the application of reinforcement increases the deformation capacity, controls the crack opening and allows a better distribution of stresses. Longitudinal reinforcements (vertical in case of walls and horizontal in case of beams) increase the flexural strength, even if they seem not to influence the shear behaviour. Transversal reinforcements (horizontal in case of walls and vertical in case of beams) increase the shear strength, even if they do not influence the flexural behaviour. Effectiveness of reinforcements on the increase of the resistance of masonry walls and beams is highly related to the failure mode of the element. Based on numerical and experimental results, a new analytical method is proposed for the design of masonry walls and beams subjected to in-plane loading. Comparison between the results provided by the proposed method with other design methods presented in literature and experimental results of several authors is presented.
As paredes consistem no elemento estrutural responsável pela estabilidade global dos edifícios em alvenaria estrutural quando sujeitos a acções laterais como vento e sismos. Estes elementos estão sujeitos a forças verticais e adicionalmente a momentos flectores e esforços de corte devido as forças laterais. Um elemento estrutural secundário mas muito importante na interacção de paredes são as vigas sobre as aberturas. Este elemento permite a transferência de esforços entre os troços de parede e confere uma maior rigidez à estrutura. O comportamento anisotrópico da alvenaria aliado ao estado bi-axial de tensão provocado pela combinação dos esforços referidos torna o comportamento das paredes e vigas bastante complexo. Desta forma, este trabalho tem como principal objectivo a melhor compreensão do comportamento de paredes e vigas de alvenaria quando sujeitos a acções no plano e a proposição de um método de dimensionamento para estes elementos. Assim, com base na revisão bibliográfica relativa ao comportamento de paredes e vigas de alvenaria, tanto em termos numéricos quanto experimentais, é proposto um plano extenso de ensaios para a caracterização mecânica dos materiais, para o estudo do comportamento de paredes sob a acção combinada de forças verticais e horizontais cíclicas aplicadas no plano das paredes e, finalmente, para o estudo do comportamento de vigas de alvenaria sujeitos à flexão e ao corte. Com base nos resultados experimentais é feita a calibração de um micro-modelo numérico com o aplicativo DIANA®, utilizando como ferramenta básica o método dos elementos finitos (MEF). Além disso, uma análise paramétrica é realizada nas paredes e nas vigas para avaliar o efeito das condições de fronteira, da geometria, da relação altura/largura dos elementos e das percentagens de armadura transversal e longitudinal. Os resultados indicam que o comportamento das paredes e vigas é descrito pelos mesmos mecanismos de resistência. Ambos os elementos apresentam um comportamento bastante frágil quando não são armados. Por outro lado, a utilização de armaduras aumenta a capacidade de deformação, controla a abertura de fissuras e permite uma melhor distribuição de tensões. As armaduras longitudinais (verticais no caso das paredes e horizontais no caso das vigas) aumentam a resistência à flexão dos elementos mas parecem não ter grande influência no comportamento ao corte. As armaduras transversais (horizontais no caso das paredes e verticais no caso das vigas) aumentam a resistência ao corte dos elementos não tendo grande influência no comportamento à flexão. A eficiência das armaduras no aumento de resistência das paredes e vigas está bastante relacionada com o modo de ruptura. Com base nos resultados numéricos e experimentais é proposto um método de dimensionamento de paredes e vigas sujeitos a acções no plano. A comparação dos resultados fornecidos pelo método proposto e por outros métodos de dimensionamento com resultados experimentais de diversos autores é apresentada.
European Union Programme of High Level Scholarships for Latin America - Programme Alβan nº E06D100148BR

This chapter emphasizes on the static and dynamic characteristics of multi-story building subjected to uniformly distributed and wind load. First-order shear deformation theory is used to formulate governing equations based on the finite element method. The multi-story building is considered as a vertical cantilever beam/plate and modeled using nine-node degenerated shell element. Fictitious membrane and shear stresses are eliminated by considering Mixed Interpolation Tonsorial Component (MITC) technique. Here, the static and dynamic characteristics of multi-story buildings have been investigated take into account as a vertical cantilever plate subjected to UDL, triangular load (wind load) and combination of both. In this chapter authors demonstrated the deformation shapes, longitudinal stress and in-plane shear stress and principle strains in various loading conditions of vertical cantilever flat panel. Moreover, investigated the dynamic characteristics of multi-story buildings considering as a vertical cantilever plates and governing equations of motion are derived by employing Hamilton’s principle. Moreover, nonlinear transient response of high-rise structures has been studied here by employing the energy and momentum conservation implicit time integration scheme. The structural analysis of tall buildings has been carried out here through commercial software ANSYS. Matrix amplitude method is employed to investigate the large-amplitude flexural vibration responses of flat panels. Also, plotted the fast Fourier transform and phase portraits for first three bending modes.

In this study, for the stiffened panels subjected to the in-plane cyclic compression loads, the two followings are clarified. One is a generating process of the cumulative buckling deformation at panel parts of stiffened panels. The other is the effect of the cumulative buckling deformation on the ultimate strength of stiffened panels. To clarify them, the cyclic compression loading experiments were carried out with two stiffened panel specimens by using Multi Axis Loading System in National Maritime Research Institute (NMRI) in Japan. For one stiffened panel specimen, the thirty-one sets of compression test cases were conducted with different strokes and for each case. The number of cycles in each set was 100. While, for the other, it was subjected to the cyclic compression loads until it collapsed. In addition, Finite Element Method (FEM) analyses for stiffened panels subjected cyclic compression loads are carried out with the same condition as the experiments by using commercial FEM software, LS-DYNA.

In steel frame structures, composite floor is an important element that plays a significant role in contributing to lateral stability. Its working role in the in-plane action is to transfer lateral loads, such as wind loads and seismic loads, to vertical load-resisting members. Such load transferring process depends on the in-plane capacities of the floor, which can be reduced after being subjected to explosion. However, the remaining capacities have not been previously studied yet in the literature. This paper presents an experimental investigation on the initial and residual in-plane capacities of the composite steel-concrete floor after being subjected to explosion, which was made within the RFCS research project BASIS:“Blast Action on Structures In Steel”. Large-scale experimental tests on four composite floor specimens, consisting of a reinforced concrete panel casted on a profile steel sheet Comflor, are performed to determine the in-plane capacities. The initial damaging of the composite floor caused by the explosion is reproduced by a flexural test using a quasi-static loading. In the in-plane shear tests, special connections between the rigid frames of the shear rig and the embedded bolts in the concrete are used to ensure a good transferring of the applied load. The results from this experimental study are the first insights on the behavior of the composite floor with and without initial pre-damaging. They can also be useful for a preliminary recommendation to estimate residual in-plane capacities (stiffness and resistance) of the composite floor after being subjected explosion.