scholarly journals Environmental and Economic Impact of Retrofitting Techniques to Prevent Out-of-Plane Failure Modes of Unreinforced Masonry Buildings

2021 ◽  
Vol 13 (20) ◽  
pp. 11383
Author(s):  
Linda Giresini ◽  
Claudia Casapulla ◽  
Pietro Croce
Keyword(s):  
Environmental Impact ◽  
Failure Modes ◽  
Energy Savings ◽  
Energy Performance ◽  
Masonry Buildings ◽  
Plane Failure ◽  
Seismic Displacement ◽  
Cost Curves ◽  
Integrated Intervention ◽  
Out Of Plane

This paper presents an innovative methodology to assess the economic and environmental impact of integrated interventions, namely solutions that improve both structural and energy performance of existing masonry buildings, preventing out-of-plane modes and increasing their energy efficiency. The procedure allows the assessment of the environmental and the economic normalized costs of each integrated intervention, considering seismic and energy-saving indicators. In addition, the work introduces in relative or absolute terms two original indicators, associated with seismic displacement and thermal transmittance. The iso-cost curves so derived are thus a powerful tool to compare alternative solutions, aiming to identify the most advantageous one. In fact, iso-cost curves can be used with a twofold objective: to determine the optimal integrated intervention associated with a given economic/environmental impact, or, as an alternative, to derive the pairs of seismic and energy performance indicators associated with a given budget. The analysis of a somehow relevant case study reveals that small energy savings could imply excessive environmental impacts, disproportionally increasing the carbon footprint characterizing each intervention. Iso-cost curves in terms of absolute indicators are more suitable for assessing the effects of varying acceleration demands on a given building, while iso-cost curves in terms of relative indicators are more readable to consider a plurality of cases, located in different sites. The promising results confirm the effectiveness of the proposed method, stimulating further studies.

scholarly journals Numerical Simulation of Unreinforced Masonry Buildings with Timber Diaphragms

Buildings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 205
Author(s):  
Igor Tomić ◽  
Francesco Vanin ◽  
Ivana Božulić ◽  
Katrin Beyer
Keyword(s):  
Failure Modes ◽  
Unreinforced Masonry ◽  
Masonry Walls ◽  
Masonry Buildings ◽  
Seismic Behaviour ◽  
Plane Failure ◽  
Friction Resistance ◽  
Flexible Diaphragms ◽  
Out Of Plane ◽  
Equivalent Frame

Though flexible diaphragms play a role in the seismic behaviour of unreinforced masonry buildings, the effect of the connections between floors and walls is rarely discussed or explicitly modelled when simulating the response of such buildings. These flexible diaphragms are most commonly timber floors made of planks and beams, which are supported on recesses in the masonry walls and can slide when the friction resistance is reached. Using equivalent frame models, we capture the effects of both the diaphragm stiffness and the finite strength of wall-to-diaphragm connections on the seismic behaviour of unreinforced masonry buildings. To do this, we use a newly developed macro-element able to simulate both in-plane and out-of-plane behaviour of the masonry walls and non-linear springs to simulate wall-to-wall and wall-to-diaphragm connections. As an unretrofitted case study, we model a building on a shake table, which developed large in-plane and out-of-plane displacements. We then simulate three retrofit interventions: Retrofitted diaphragms, connections, and diaphragms and connections. We show that strengthening the diaphragm alone is ineffective when the friction capacity of the wall-to-diaphragm connection is exceeded. This also means that modelling an unstrengthened wall-to-diaphragm connection as having infinite stiffness and strength leads to unrealistic box-type behaviour. This is particularly important if the equivalent frame model should capture both global in-plane and local out-of-plane failure modes.

Seismic fragility of regular masonry buildings for in-plane and out-of-plane failure

2014 ◽  
Vol 6 (6) ◽  
pp. 689-713 ◽  
Author(s):  
Fillitsa Karantoni ◽  
Georgios Tsionis ◽  
Foteini Lyrantzaki ◽  
Michael N. Fardis
Keyword(s):  
Seismic Fragility ◽  
Masonry Buildings ◽  
Plane Failure ◽  
Out Of Plane

Simulation of masonry out-of-plane failure modes by multi-body dynamics

2015 ◽  
Vol 44 (14) ◽  
pp. 2529-2549 ◽  
Author(s):  
Alexandre A. Costa ◽  
Andrea Penna ◽  
António Arêde ◽  
Aníbal Costa
Keyword(s):  
Failure Modes ◽  
Plane Failure ◽  
Body Dynamics ◽  
Out Of Plane ◽  
Multi Body

scholarly journals In-Plane and Out-of Plane Failure of an Ice Sheet using Peridynamics

2020 ◽  
Vol 36 (2) ◽  
pp. 265-271 ◽  
Author(s):  
Bozo Vazic ◽  
Erkan Oterkus ◽  
Selda Oterkus
Keyword(s):  
Failure Modes ◽  
Ice Sheet ◽  
Offshore Structures ◽  
Mindlin Plate ◽  
Plane Case ◽  
Plane Failure ◽  
Structure Interaction ◽  
Winkler Elastic Foundation ◽  
Peridynamic Model ◽  
Out Of Plane

ABSTRACTWhen dealing with ice structure interaction modeling, such as designs for offshore structures/icebreakers or predicting ice cover’s bearing capacity for transportation, it is essential to determine the most important failure modes of ice. Structural properties, ice material properties, ice-structure interaction processes, and ice sheet geometries have significant effect on failure modes. In this paper two most frequently observed failure modes are studied; splitting failure mode for in-plane failure of finite ice sheet and out-of-plane failure of semi-infinite ice sheet. Peridynamic theory was used to determine the load necessary for inplane failure of a finite ice sheet. Moreover, the relationship between radial crack initiation load and measured out-of-plane failure load for a semi-infinite ice sheet is established. To achieve this, two peridynamic models are developed. First model is a 2 dimensional bond based peridynamic model of a plate with initial crack used for the in-plane case. Second model is based on a Mindlin plate resting on a Winkler elastic foundation formulation for out-of-plane case. Numerical results obtained using peridynamics are compared against experimental results and a good agreement between the two approaches is obtained confirming capability of peridynamics for predicting in-plane and out-of-plane failure of ice sheets.

scholarly journals The Environmental Impact Reduction obtained by implementing an Energy Management System. The advantages of using Energy Management and Energy Savings Standards when performing Industrial Energy Audits

2019 ◽  
Vol 112 ◽  
pp. 04007
Author(s):  
Mircea Scripcariu ◽  
Ioan Sevastian Bitir-Istrate ◽  
Cristian Gheorghiu ◽  
Aida Maria Neniu
Keyword(s):  
Energy Efficiency ◽  
Environmental Impact ◽  
Energy Management ◽  
Energy Use ◽  
Energy Savings ◽  
Distribution Networks ◽  
Energy Performance ◽  
Energy Efficiency Improvement ◽  
Impact Reduction ◽  
Energy Audits

Energy audits are used world-wide for developing energy efficiency projects. Industrial consumers have complex energy supply, generation and distribution networks and a variety of energy use installations. Romanian industrial companies became more interested in the last years in implementing Energy Management Systems in accordance with ISO 50001 standard. This paper presents a comparison of using the current way of developing energy audits and the concepts provided by the ISO group of standards, by quantifying the environmental impact reduction generated by each methodology. Authors pointed out that current legislation does not fully match the rigors of the ISO 50001 group of standards when evaluating the Energy Baseline (EB), the Energy Performance Indicators (EPI) or the Energy Performance Improvement Actions (EPIA), thus leading to a lower global energy efficiency improvement in the hypothesis of implementing all the recommended EPIAs [1]. Identifying and developing energy efficiency measures following the recommendations of the energy management and energy savings group of standards may be more consistent and less risky for the industrial company, which in turn can lead to an overall improvement of the Carbon Footprint [2].

scholarly journals Seismic Design of Box-Type Unreinforced Masonry Buildings Through Direct Displacement-Based Approach

2016 ◽  
Vol 10 (1) ◽  
pp. 293-311 ◽  
Author(s):  
Fulvio Parisi
Keyword(s):  
Seismic Design ◽  
Failure Modes ◽  
Unreinforced Masonry ◽  
Masonry Building ◽  
Masonry Buildings ◽  
Construction Costs ◽  
Plane Failure ◽  
Accidental Eccentricity ◽  
Reinforced Concrete Slabs ◽  
Displacement Based

In the last decade, displacement-based seismic design procedures have been recognised to be effective alternatives to force-based design (FBD) methods. Indeed, displacement based design (DBD) may allow the structural engineer to get more realistic predictions of local and global deformations of the structure, and hence damage, under design earthquakes. This facilitates the achievement of performance objectives and loss mitigation in the lifetime of the structure. Nonetheless, DBD needs further investigation for some structural types such as masonry buildings. In this paper, a direct displacement based design (DDBD) procedure for unreinforced masonry (URM) buildings is presented and critically compared to FBD. The procedure is proposed for box-type URM buildings with reinforced concrete slabs, bond beams and lintels above openings, which have shown acceptable seismic performance in severe earthquakes preventing out-of-plane failure modes. Seismic design of a three storey brick masonry building in a high seismicity region is discussed as a case study. The effects of ordinary and near-field design earthquakes, as well as load combinations and accidental eccentricity prescribed by current codes, were investigated. Finally, design solutions provided by FBD and DDBD were optimised and their construction costs were estimated. It was found that, particularly at small epicentral distances, neglecting the combination of horizontal seismic actions and accidental eccentricity may induce significant underestimation and an ideally more uniform distribution of strength demands on URM walls. In addition, construction costs resulting from DDBD may be significantly lower than those related to code based FBD procedures.

Numerical Prediction of Failure in Unidirectional Fiber Reinforced Composite

2021 ◽  
pp. 2150073
Author(s):  
Ignacio Valdivia ◽  
Cristian Canales ◽  
Víctor Tuninetti ◽  
Paulo Flores ◽  
Carlos Medina
Keyword(s):  
Failure Modes ◽  
Transverse Isotropy ◽  
Failure Criteria ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Plane Failure ◽  
Fiber Reinforced Composite ◽  
Unidirectional Fiber ◽  
Reinforced Composite ◽  
Out Of Plane

Fiber-reinforced polymer composites exhibit orthotropic mechanical properties and particularly low strength in the out-of-plane direction. The use of classical failure criteria that consider transverse isotropy to evaluate these composite materials implies an overestimation of their out-of-plane strength, which could lead to a nonconservative and even catastrophic design. The Molker failure criteria developed for orthotropic materials consider the LaRC05 failure modes as a basis, with two additional failure modes for the out-of-plane direction of noncrimp fiber (NCF)-reinforced composites. Given the similarity in configuration and orthotropic behavior of unidirectional fiber fabric reinforced composites to NCF-reinforced composites, Molker failure criteria are implemented and applied in this research to determine the initiation of out-of-plane failure in unidirectional fiberglass fabric composites. The criteria are programmed in the form of a module coupled to a constitutive model available in a finite element method (FEM) package. Then, the mechanical properties and failure parameters of the unidirectional fiber-reinforced composite are determined. Model validation is accomplished by comparing numerical and experimental results of out-of-plane failure in a corrugated panel. In addition, several failure criteria used in unidirectional fiber-reinforced composite that consider transverse isotropy are evaluated. The results of critical load at the onset of transverse out-of-plane failure obtained by using the Molkerorthotropic criterion prove to be superior in accuracy compared to those obtained with the criteria commonly applied to this type of materials.

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