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Incremental sheet forming has emerged as an excellent alternative to other material forming procedures, incrementally deforming flat metal sheets into complex three-dimensional profiles. The main characteristics of this process are its versatility and cost-effectiveness; additionally, it allows for greater formability compared to conventional sheet forming processes. Recently, its application has been extended to polymers and composites. The following review aims to present the current state of the art in the incremental sheet forming of polycarbonate, an outstanding engineering plastic, beginning with initial studies on the feasibility of this process for polymers. Attention is given to the advantages, drawbacks, and main applications of incrementally formed polycarbonate sheets, as well as the influence of process parameters and toolpath strategies on features such as formability, forming forces, deformation and failure mechanisms, geometric accuracy, surface quality, etc. Additionally, new hybrid forming methods for process optimisation are presented. Finally, a discussion is provided on the technical challenges and future research directions for incremental sheet forming of polycarbonate and, more generally, thermoplastics. Thus, this review aims to offer an extensive overview of the incremental forming of polycarbonate sheets, useful to both academic and industrial researchers working on this topic.

The awareness of the vulnerability of existing structures under both seismic and energy perspectives highlights the need for integrated retrofit solutions that combine structural and thermal enhancements. From this perspective, this study explored the efficacy of the Resisto 5.9 Tube system, which is a seismic retrofit solution for masonry and reinforced concrete (RC) structures that also improves the energy performance by integrating a thermal coat integrated within its basic steel framework. This research involved application to a RC building of a design procedure specifically developed for this system that was aimed at facilitating its adoption by designers involved in seismic retrofitting analysis. After designing the system components, nonlinear static analyses were performed using finite element software to compare the building’s seismic performance before and after the application of the Resisto 5.9 Tube. The results demonstrate a significant increase in the seismic safety coefficient ζE from 0.26 to 0.42, which proved the potential of this intervention to enhance the seismic safety of existing RC buildings.

Incremental sheet forming represents a relatively recent technology, similar to the layered manufacturing principle of the rapid prototype approach; it is very suitable for small series production and guarantees cost-effectiveness because it does not require dedicated equipment. Research has initially shown that this process is effective in metal materials capable of withstanding plastic deformation but, in recent years, the interest in this technique has been increasing for the manufacture of complex polymer sheet components as an alternative to the conventional technologies, based on heating–shaping–cooling manufacturing routes. Conversely, incrementally formed polymer sheets can suffer from some peculiar defects, like, for example, twisting. To reduce the risk of this phenomenon, the occurrence of failures and poor surface quality, a viable way is to choose toolpath strategies that make the tool/sheet contact conditions less severe; this represents one of the main goals of the present research. Polycarbonate sheets were worked using incremental forming; in detail, cone frusta with a fixed-wall angle were manufactured with different toolpaths based on a reference and a stair strategy, in lubricated and dry conditions. The forming forces, the forming time, the twist angle, and the mean roughness were monitored. The analysis of the results highlighted that a stair toolpath involving an alternation of diagonal up and vertical down steps represents a useful strategy to mitigate the occurrence of the twisting phenomenon in incremental formed thermoplastic sheets and a viable way of improving the process towards a green manufacturing process.

The aim of this paper is to establish a valid procedure for better understanding all of the phenomena associated with the high-speed machining of glass fiber-reinforced plastic (GFRP) composites. Both rectangular and circular specimens were machined at high cutting speeds (up to 50 m/min) in order to understand what occurred for all values of fiber orientation angles during machining operations. An innovative testing methodology was proposed and studied to investigate the phenomenon of burr formation and thus understand how to avoid it during machining operations. To this end, the forces arising during the machining process and the roughness of the resulting surface were carefully studied and correlated with the cutting angle. Additionally, the cutting surface and chip morphology formed during cutting tests were examined using a high-speed camera. Close correlations were found between the variations in the cutting forces’ signals and the trends of the surface roughness and the morphology of the machined surface.

The safety of the built heritage of our cities towards environmental factors and seismic actions is a pressing need for designers and researchers. The actual trend is to setup effective solutions to reduce thermal dispersions through the building envelope. Contrarily, combined systems able to enhance the resistance of constructions to earthquakes, on the one hand, and, on the other hand, to increase the energetic efficiency of existing buildings are scarcely diffused on the market and are rarely investigated in the scientific literature. In this framework, the seismic design of the new envelope DUO system for seismic-environmental requalification of existing masonry constructions is illustrated in the present paper with reference to a case study in the Neapolitan area. After the geometrical and mechanical characterization of the investigated building is performed, an FEM model of the masonry construction is setup by the SAP2000 analysis program, which has allowed performing pushover analyses. Based on the non-linear seismic response of the construction, an appropriate upgrading design mainly based on the innovative seismic envelope DUO system has been made. The static non-linear analyses applied to the upgraded FEM model of the building have shown a clear increase in performance in terms of strength, stiffness and ductility, thus confirming the effectiveness of the proposed envelope system.

The European building stock presents pertinent issues needing suitable strategies to be solved. In detail, this regards seismic safety and energy efficiency of buildings to ensure more liveable and safe cities, which represents an important goal for modern societies. Energy performance includes both comfort and saving, the latter required for a more responsible resource consumption within the building sector, having a considerable contribution to the total demand. Current strategies do not seem to be able to simultaneously solve such aspects satisfactorily, both for higher economic requirements and poor technical feasibility implied by separated and disharmonious interventions. Thus, a holistic perspective should be adopted to pursue such an ambitious objective, which has recently gained increasing attention among researchers. Current requirements are firstly highlighted to show the need for an integrated approach to building retrofit. Secondly, a critical review of integrated strategies combining seismic and energy refurbishment proposed in the literature is reported. Then, special issues are discussed, including the feasibility of an integrated approach applied to heritage buildings. This study revealed that a fully efficient strategy for integrated retrofit has not still been proposed in the literature and there are several open issues to be solved. However, current solutions may be further developed to improve them and the several options currently available demonstrated the increasing attention and importance of the topic. Finally, concluding remarks on this research topic have been drawn to promote future studies.

The present paper aims at inspecting the structural behaviour of a typical masonry aggregate located in the historical centre of Cercola, a municipality in the province of Naples. The clustered building under study consists of four structural units mutually connected to each other made of tuff stone and deformable floors. Two distinct structural units, namely in heading and intermediate places, in both isolated and aggregate conditions, are examined to estimate the influence of structural positions on the global seismic response of the examined case study buildings. For this purpose, non-linear static analyses are performed using the 3MURI software. Pushover analyses are conducted to both evaluate the seismic behaviour of examined structural units and improve their earthquake performances while considering proper retrofit interventions on vertical and horizontal structures. The analysis results are plotted in terms of risk factor, stiffness, and ductility. Finally, a set of fragility functions are derived to point out the structural response of the case study buildings before and after retrofit interventions. From the achieved results, it is highlighted that retrofit interventions improve the structural performances of the buildings, especially those of structural units in aggregate conditions.

Conservation of historical centres is a pressing need for Mediterranean countries, that are characterized by masonry aggregates representing the most typical construction type within cities. Masonry clustered buildings were usually designed without seismic design criteria. Moreover, the current seismic standard codes do not foresee a clear calculation method to predict their non-linear behaviour. For this reason, in this paper, a wide overview on the seismic response of masonry aggregates has been done considering analysis at different levels, from simplified large-scale evaluations to sophisticated non-linear analyses. In the former investigation kind, a vulnerability form appropriately conceived for clustered buildings has been applied to different historical centres with the aim to perform risk analysis considering both empirical approaches and real data deriving from occurred past earthquakes. In the second evaluation type, the macro-elements analysis method has been examined with reference to typical clustered buildings of the Italian territory. In particular, global assessments, performed using the 3Muri non-linear analysis program, have been performed with the final goal to derive fragility curves of structural units of masonry aggregates considering their plan position in the clustered building (end of row, internal, and corner).

Seismic codes were developed to reduce the structural vulnerability and risk associated with earthquakes in earthquake-prone regions of the world. The effectiveness of the code in preventing damage is dependent on the performance level defined and the construction technology employed. The seismic fragility curves for two recent versions of the seismic code of Iran are determined by using the hybrid method. The probability of damage levels is visualized by these curves. To develop these curves, only the assumptions of the code are taken into account. These curves are compared with the empirical fragility of the recent devastating earthquake in Iran. The results indicate that, despite a similar probability of damage to the different seismic-resistant systems, steel-braced frames pose a greater risk of collapse. Concerning earthquake damage, the steel and RC moment-resisting frames have shown higher damage probability than expected from the code.

The management of plastic waste has become a fundamental issue in recent decades and several studies have focused on finding proper solutions to recycle and reuse these secondary raw materials in different sectors. Using plastic waste in the building sector allows for long-term application and reduces the number of times the recycling process is needed. This research focuses on experimenting with two building products, namely lightweight screed and concrete, with the addition of plastic waste in the form of irregular granules. The screed was produced by adding plastic granules of different sizes, while the concrete was produced by replacing different percentages of the coarse and fine aggregates with plastic granules and pulverized plastic. The screed has been tested under compressive and three-point bending tests, while the concrete has only been tested under compressive tests. The results have shown that the addition of plastic waste in both products led to the desired weight reduction. On one hand, plastic waste have provided a decrease in both tensile (−16%) and compressive (−25%) strengths of the screed with an increase of ultimate tensile strain (+60%). On the other hand, the only acceptable concrete mixture resulted to be the one with 25% of aggregates substitution, which exhibited a decrease in compressive strength (−40%) and an increase of ultimate strain (+38%), whereas samples with higher percentages of plastic aggregates have been not considered to be suitable as building materials.

Additive manufacturing is an emerging disruptive 3D printing technology that is stimulating innovations in design and engineering, materials, and manufacturing thanks to the prospects of reducing cost and waste and increasing efficiency; in doing so, it presents the potential to have marked industrial, economic, and societal impacts. Thermoplastic polymers show some ideal characteristics for the most common additive manufacturing methods, and this aids in the improvement of the design accuracy and reliability and makes inroads for the customized manufacturing of high-design-flexibility polymer parts. Despite this, this material family is strongly sensitive to temperature, and one of the viable ways of limiting this weak point is surface coating with thermal barriers. The focus of this work was the optimization of an additive manufacturing process for producing thermoplastic components and to improve the adhesion of a thermal barrier coating on their surface. In detail, flat plate specimens of ULTEM 1010 were obtained by the fused deposition modeling technique by varying two significant surface parameters, the enhanced visible rasters and the visible raster air gap; then, their surfaces were covered by a thin ceramic coating by an air plasma spray system. A micro-geometric analysis that was conducted using a confocal microscope and the coating thickness measurements highlighted that a global larger roughness value, the presence of more flat peaks with a large area, and the complexity of the texture can be considered as supporting factors for improving the mechanical gripping and allowing a uniform adhesion of the coating powders on the thermoplastic substrate.

Fibre-reinforced plastic (FRP) materials are attracting growing interest because of their high specific mechanical properties. These characteristics, in addition to a high level of tailorability and design of freedom, make them attractive for marine, aerospace, automotive, sports and energy applications. However, the large use of this class of material dramatically increases the amount of waste that derives from end-of-life products and offcuts generated during the manufacturing processes. In this context, especially when thermosetting matrices are considered, the need to deeply study the recycling process of FRPs is an open topic both in academic and industrial research. This review aims to present the current state of the art of the most affirmed recycling technologies used for polymeric composites commonly used in industrial applications, such as carbon and glass FRPs. Each recycling method (i.e., chemical, thermal and mechanical) was analysed in terms of technological solutions and process parameters required for matrix dissolution and fibre recovery, showing their advantages, drawbacks, applications and properties of the recycled composites. Therefore, the aim of this review is to offer an extensive overview of the recycling process of polymeric composite materials, which is useful to academic and industrial researchers that work on this topic.

Local collapse mechanisms related to the out-of-plane response of walls are commonly observed in existing masonry buildings subjected to earthquakes. In such structures, the lack of proper connections among orthogonal walls and between walls and floors does not allow a global box-type behaviour of the building to develop, which would be governed by the in-plane response of walls. In this paper, parametric linear kinematic analyses on the main local mechanisms of masonry churches were performed with the aim to evaluate the corresponding horizontal load multipliers. This study was conducted on 12 masonry churches, located in Teramo (Italy) and affected by the 2016 Central Italy earthquake, whose main out-of-plane collapse mechanisms, namely facade overturning, vertical bending, corner overturning and roof gable wall overturning, have been analysed. For each mechanism, parametric analysis was carried out on varying heights and thicknesses of walls. Firstly, the acceleration values activating the considered mechanisms were calculated in order to conduct checks prescribed by the current Italian standard. Subsequently, on the basis of the obtained results, simple analytical procedures to determine load collapse multiplier for each mechanism were drawn. Finally, ranges of suitable values of both the thickness and height of walls were found in order to always satisfy seismic checks.

This paper addresses the importance of engineering asset management decisions and control. For this purpose, a Life-Cycle Cost (LCC) analysis is conducted for typical reinforced concrete (R/C) buildings located in Mexico City. The objective of this study is to develop an artificial neural network (ANN) model that can estimate the total expected cost of R/C buildings by using LCC functions. The total cost includes the initial cost and the cost of the damage caused by future possible ground motions at the site of interest. The present value of the cost includes: initial cost, repair or reconstruction cost, cost of damage to the contents, costs associated with the loss of life or injuries and economic losses. The structural performance is evaluated using probabilistic models, artificial neural networks models are used to obtain the seismic response of the buildings. The methodology is applied to a set of reinforced concrete buildings with 4, 8, and 12 stories which are located at the soft soil of Mexico City. Finally, it is concluded that the life-cycle cost is efficiently obtained using artificial neural network models for estimating the structural reliability of reinforced concrete buildings, in such a way that it can be used as an excellent planning tool that covers long spans of time.

Historical structures represent a significant percentage of existing constructions in numerous seismic-prone regions, and some of these are iconic monuments of their countries [...]

Carbon fiber-reinforced plastics (CFRPs) are composite materials that play a significant role in the growth of many industrial fields where high performance and lightness of the structures are required. At the same time, the management at the end of their life has required the development of more and more sustainable and efficient recycling solutions. Considering this, the present research work aims to investigate a mechanical recycling method and the cutting strategies able to machine CFRP components in their entirety, using a common milling machine in a job shop scheme, making a shorter supply chain, and leading to economic and environmental benefits. In detail, laminates obtained by unidirectional carbon fiber prepregs were worked through the peripheral down-milling process, by varying the spindle speed and the feed rate. The recording of the cutting forces enabled the evaluation of features such as the cutting power and the specific cutting energy. Moreover, the chips from the milling process were classified as a function of their dimensions. Finally, specimens made of chips and epoxy resin were characterized under bending conditions, to evaluate the effectiveness of using the chips from CFRP peripheral milling as the polymer’s reinforcement and, in addition, to appreciate the goodness of this recycling strategy.

Incremental sheet forming represents a relatively new process appointed to form sheets of pure metals, alloys, polymers, and composites for the manufacture of components in fields where customized production in a short time and at a low cost is required. Its most common variant, named single-point incremental forming, is a flexible process using very simple tooling; the sheet is clamped along the edges and a hemispherical-headed tool follows a required path, to deform the sheet locally. In so doing, better formability is reached without any dedicated dies and for low-forming forces, which represent some of the attractive features of this process. Nevertheless, and with special reference to thermoplastic sheets, incremental formed parts suffer from peculiar defects like twisting and wrinkling. In this numerical work, analyses were conducted through a commercial finite element code by varying the toolpath strategy of the incremental forming of polycarbonate sheets. The investigation of some features like the forming forces, the deformation states, the energy levels, and the forming time was carried out, to determine the toolpath strategy able to optimize the incremental forming process of polymer sheets. The results of the numerical analyses highlight a reduction of the forming forces when using toolpaths alternating diagonal up and vertical down steps and, presumably, a reduced risk of failures and defects. Furthermore, these toolpath strategies solutions also have a positive impact on the environment in terms of energy and do not significantly increase the manufacturing time.

Since laboratory tests are usually costly, simulating methods using computers are always under the spotlight. This study performed a finite element analysis (FEA) using iterative solutions for simulating circular and square concrete-filled steel tube (CFST) columns infilled with high-strength concrete and reinforced with a cross-shaped plate (comprising two plates along the columns that divide the hollow columns into four equal sections) with and without opening. For this reason and for validation purposes, the columns had length of 900 mm, width/diameter of 150 mm and wall thickness of 3 mm. In this study, unlike in some other studies, the cross-shaped plate was assumed to be fixed at the top and the bottom of a column, and the columns were subjected to axial compression pointed in the center. The outcomes revealed that the cross-shaped plate could improve the axial strength of both circular and square CFST columns; however, the structural performance of the square CFST columns changed: local outward buckling was observed after inserting the cross-shaped plate. By inserting an opening on the cross-shaped plate, the bearing capacity of the circular CFST columns was further improved, while the square CFST columns experienced a decline in their ultimate bearing capacity compared with the corresponding models without the opening. The lateral deflection also improved for the circular CFST columns by adding the reinforcement. However, for the square CFST columns, while it initially improved, increasing the thickness of the cross-shaped plate inversely influenced the lateral deflection of the square CFST columns. The results were also compared with some available codes, and a good agreement was achieved with those outcomes.

The paper discusses the seismic vulnerability of structures susceptible to overcrowding due to their intended use. Specifically, it addresses the analysis towards earthquake actions of a masonry school located in the Municipality of San Giorgio a Cremano, within the neighbourhood of Naples, providing different reinforcement interventions to ensure its seismic consolidation. After a brief introduction, the description of the analysis representative of the current condition of the structure is performed considering both static and seismic actions. The analysis results determine the seismic risk class of the building, allowing to identify its deficiencies, so to design structural consolidation interventions following the standard code indications. In particular, two retrofit techniques, namely, FRP and FRCM systems, are proposed with the purpose to evaluate their benefits to the school building from a seismic viewpoint. Finally, a comparison between the proposed intervention techniques is made to establish which one guarantees the best upgrading of the seismic condition of the examined building.

In recent years, new solutions have been studied in order to intervene on existing buildings made of load-bearing masonry or reinforced concrete, both from the seismic point of view and the energy one. In recent years, novel modern techniques using lightweight steel profiles made of steel or aluminium alloys, suitably coupled with heat-insulating panels, have been proposed for requalification of existing building stock. In this paper, the Resisto 5.9 system designed by the Progetto Sisma S.r.l. company was studied and applied as a retrofit system of an existing masonry building. First, this new system for seismic energy requalification of the build-up was presented, describing the basic components and the mounting phases. Subsequently, it has applied to a case study building made of full-brick masonry located in the municipality of Casalecchio di Reno, on the outskirts of Bologna in Northern Italy. Finally, the used coating system was designed for the examined building together with other seismic interventions applied to horizontal structures and foundations. The seismic benefits deriving from using the proposed envelope system and other seismic interventions were proved from the seismic viewpoint by linear dynamic and non-linear static analyses using the TreMuri analysis software. From modal analysis it was seen that the dynamic behaviour of the building with Resisto 5.9 is improved, with an increase of the participating mass (68% instead of 49% of the bare building) of the second mode in the longitudinal direction. Moreover, from pushover analysis it was noticed that the seismic safety factor has passed from 0.51 to 1.05 in the X-direction and from 0.78 to 1.27 in the Y-direction. In conclusion, it was demonstrated that Resisto 5.9, together with all the other planned interventions, is able to accomplish the seismic retrofitting of the studied building.

The frequency content and time duration of earthquakes are as effective as the peak ground acceleration on structural damage. Therefore, using rapid seismic vulnerability assessment methods that consider the earthquake acceleration time history is noticeable. Kermanshah is a historical city that is generally affected by far-field earthquakes. Therefore, it is necessary to consider the effect of the low-frequency shocks in evaluating the vulnerability of buildings in this city. Herein, a historic school in Kermanshah is assumed as a case study and two well-known damage index formulas are used for determining the damage index spectra of this structure, considered as a single degree of freedom system. Then, the effective parameters of the damage index, including ductility, relative degradation of stiffness, and dissipated energy are determined from a nonlinear analysis of the structure under the effect of the most probable earthquake acceleration records. Finally, the damage index spectra can be used for rapid seismic vulnerability assessment of masonry buildings on similar sites with various fundamental periods for large-scale assessments. The result shows that the building tends to collapse at a peak ground acceleration of 0.15 g. Furthermore, results confirm the seismic resistance reduction effect of flexible floors.

Seismic upgrading and retrofitting of existing constructions is a pressing need for designers and researchers. The necessity of efficient seismic upgrading/retrofitting techniques is, therefore, required in seismic-prone countries, such as Italy. In this framework, steelwork has clearly shown many advantageous applications in the last century. Nonetheless, if compared to other different technologies, steelwork is still limited for consolidation purposes. Moreover, the wide damage provoked by earthquakes to industrial buildings have induced scientific research to investigate the seismic vulnerability of such constructions much more. In the current study, the attention has been, therefore, focused on the use of steelwork systems as anti-seismic intervention techniques from a precast RC industrial warehouse hit by the 2012 Northern Italy earthquakes. Besides the usefulness of steelwork in implementing reliable techniques against earthquakes, the paper has the aim of discussing the different seismic behaviour of the building deriving from dissimilar beam-to-column joint types obtained using steelwork interventions. Other than the widely diffused static scheme with hinges, other types of joints (semi-rigid and rigid), along with the presence of a rigid roof, have been investigated, and the different seismic risk indicators derived from these static schemes have been achieved, highlighting the case of the best seismic behaviour of the warehouse. Finally, the effectiveness of local steel interventions in improving the efficient global response of the building has also been highlighted.

In Italy, the interest in the industrial areas dates back to 1970, when industry began to be considered as identity and memory of the population, until 1990, when industrial constructions became cultural and historical goods. This interest was also justified by the necessity to recover these often-abandoned sites through structural and seismic interventions. For this purpose, the cataloguing of the different industrial buildings in Italy was made by the Italian Consortium ReLUIS “Network of Seismic Engineering University Laboratories”, through the “Cartis Long Spans” form, to obtain indications on the seismic vulnerability of this built heritage. In the current paper, the seismic analysis and the combined seismic–energy retrofit of a former reinforced concrete tobacco factory in Cervinara, within the district of Avellino (Italy), were carried out. This work proposes a seismic retrofit intervention of the examined structure, erected at the end of the 1960s, based on the use of steel exoskeletons. The proposed intervention can be seen as a novel strategy for requalification of industrial buildings, as well as for regeneration and restoration of the value of industrial areas. It was shown that these devices allow a considerable increase of the seismic safety indices, which attain values significantly greater than 1, to reach the building retrofitting. Subsequently, a photovoltaic plant using high-efficiency panels is proposed to provide the entire hub’s energy requirement. It was found that the annual production/square meterage of the building is between 20% and 60% lower than that of school and office buildings. As a whole, the analysis results demonstrated that exoskeletons are an effective intervention to improve the seismic features of the studied industrial building without neglecting architectural quality, sustainability, and environmental issues.

The control of vibrations and damage in traditional reinforced concrete (RC) buildings under earthquakes is a difficult task. It requires the use of innovative devices to enhance the seismic behavior of concrete buildings. In this paper, we design RC buildings with buckling restrained braces (BRBs) to achieve this objective. For this aim, three traditional RC framed structures with 3, 6, and 9 story levels are designed by using the well-known technique nondominated sorting genetic algorithm (NSGA-II) in order to reduce the cost and maximize the seismic performance. Then, equivalent RC buildings are designed but including buckling restrained braces. Both structural systems are subjected to several narrow-band ground motions recorded at soft soil sites of Mexico City scaled at different levels of intensities in terms of the spectral acceleration at first mode of vibration of the structure Sa(T1). Then, incremental dynamic analysis, seismic fragility, and structural reliability in terms of the maximum interstory drift are computed for all the buildings. For the three selected structures and the equivalent models with BRBs, it is concluded that the annual rate of exceedance is considerably reduced when BRBs are incorporated. For this reason, the structural reliability of the RC buildings with BRBs has a better behavior in comparison with the traditional reinforced concrete buildings. The use of BRBs is a good option to improve strength and seismic behavior and hence the structural reliability of RC buildings subjected to strong earthquake ground motions.

The weakness of tensile strength and high weight in masonry structures under the dynamic loads of earthquakes has always led to structural damage, financial losses, injuries, and deaths. In spite of cheap and affordable masonry materials, their use has been very limited in constructions over the past three decades. However, common masonry materials are still found in monumental and historical structures, deteriorated texture, and rural buildings. Identifying the seismic behavior and the probability of the structural damage is vital for pre-earthquake seismic risk reduction of urban areas and the rapid post-earthquake assessment. The earthquake event that occurred in Ezgeleh on 2017 November 12 with Mw = 7.3 triggered the greatest damage in Sarpol-e-zahab city at a distance of about 37 km from the epicenter. Post-earthquake reconnaissance, microtremor analysis, and rapid visual inventory of structural damages in different zones were performed by research teams. In the present study, the strong ground motion and the peak ground acceleration, and its corresponding intensity distribution, which are based on the site response analysis in different parts of the city, are introduced. Afterward, damage probability matrices of different types of masonry buildings, namely unreinforced masonry and confined masonry buildings, are determined for both bins of peak ground accelerations and intensities. Finally, the fragility curves of two types of masonry structures are extracted based on the RISK-UE level 1 (LM1) method by assuming a beta distribution to estimate the probability distribution function of the damage. These curves are useful in assessing pre-earthquake possible damages in masonry structures with similar construction methods and similar materials to reduce seismic risks.

Current practices supporting sustainable building design aim at reducing the expenditure of natural resources, such as raw materials, energy and water, in the production of construction supplies. In the current paper water is replaced by fennel centrifugate (FC) for the realization of cement mortar bricks. After having identified the most suitable cementitious pre-mixed over three potential candidates, the mechanical and physical characteristics of the FC bricks are compared to cement mortar bricks, prepared with regular water, by means of bending, compression at ordinary and high temperatures, imbibition and acoustic tests. From compared results, it is noticed that FC bricks have the same imbibition property, but tensile and compression (ordinary and high temperatures) resistances have about 20% less than the control specimen ones. The acoustic tests revealed a better response of FC bricks to the high frequencies greater than 1600 Hz. However, fennel fibres do not provide a manifest advantage, likely due to the small size of the centrifuged fragments that are not able to enhance the product tensile resistance.

The Cultural heritage spread all over the World needs to be preserved with systems that do not compromise its architectural and historical value. Nowadays, the most advanced technology available is the ambient vibration test. It allows to obtain the current frequencies, modal shapes, and damping of structures, without being invasive. The comparison between different monitoring campaigns and their use in combination with Finite Element models can give an insight into the state of structures’ health. This paper presents two ambient vibration tests performed on a fortified masonry tower in the Marche region of Italy, carried out after one year each other, with different temperature and humidity conditions. To extract the structure’s dynamic parameters both a time and a frequency domain approaches were used. The comparison between the parameters obtained during the two experimental campaigns showed similar frequencies and modal shapes underlining that no damage occurred and that the dynamic response of the tower does not suffer temperature and humidity variations. In addition, the steps carried out for a first attempt manual calibration of the tower’s Finite Element model are shown. The match between the numerical model and the experimental data is evaluated through the absolute frequencies’ errors and the Modal Assurance Criteria between the modal vectors. The calibrated numerical model can be used for future and accurate assessment of the tower’s structural capacity.

The current paper aims at investigating the seismic capacity of a masonry building aggregate in the historical centre of Mirandola based on a reliable ground motion simulation procedure. The examined clustered building is composed of eleven structural units (SUs) mutually interconnected to each other, which are made of brick walls and are characterized by wooden floors poorly connected to the vertical structures. Non-linear static analyses are performed by adopting the 3Muri software to characterize the seismic capacity of both the entire aggregate and the individual SUs. In this framework, a multi-scenario physics-based approach is considered for the definition of the seismic input in terms of broadband seismic signals inclusive of source and site effects. Finally, the incidence of the seismic input variability is discussed for the prediction of the global capacity response of the case study building.

The present research aims at investigating the vibration period of structural units (SUs) of a typical masonry aggregate located in the historical center of Mirandola, a municipality in the province of Modena. The clustered building consists of eighteen SUs mutually interconnected to each other, which are characterized by solid brick walls and deformable floors. First of all, non-linear static analyses are performed by adopting the 3Muri software focusing on two distinct modelling techniques concerning the analyzed SUs in isolated and clustered configurations. Congruently to the procedure adopted, in order to evaluate a reliable seismic structural response of the SUs arranged in aggregate conditions, the contribution in terms of stiffness and mass derived from adjacent buildings is considered. The analysis results are represented in terms of risk factor, stiffness, and ductility. Secondly, the eigenvalue analysis is faithfully developed to identify the main vibration modes of the investigated SUs by proposing an empirical formulation, that allows for predicting the vibration period of structural units placed in aggregate configuration starting from the corresponding isolated ones. Finally, fragility functions are derived for both the heading and intermediate SUs to point out the expected damages under earthquakes with different intensities.

In recent years the interest for the resilience of cities and historic urban centers is growing. Climate change is one of the challenges of this century and it is having a great impact on the society and economy of cities and buildings. According to climate change scenarios cities will have to face frequent extreme events in the future years, like droughts, heat waves, abundant precipitations or snowfalls. However, there are little studies that try to analyze the effects from different points of view and to find a solution that can have an impact on buildings, the town environment as well as on the well being of the society. Therefore this article proposes a complex assessment and intervention strategy based on the case study of Oravita, a small mountain town from the western part of Romania, that will improve the resilience of the town trough a multidisciplinary approach. The aim is to understand and to adapt the historic town to the contemporary climatic needs by an interdisciplinary holistic understanding of the context through different professional views: architectural, landscape architecture, historical, engineering, social, economical and geographical.

Recent seismic events produced considerable socio-economic losses. An important step for the reduction and mitigation of seismic risk in urban areas with a high population density is the assessment of global vulnerability of clustered buildings. The proposed work aims at appraising the seismic vulnerability of building aggregates within the historical center of Arsita, damaged by the L'Aquila earthquake (2009 April 6th), through a multi-level approach deriving from the application of different estimation procedures. In particular, the seismic vulnerability quantification has been done by comparing three distinct methods, namely the macroseismic approach according to the EMS-98 scale, the Vulnus methodology, developed by the University of Padua, and the mechanical approach derived from using the 3Muri software. The expected damage has been estimated in terms of fragility curves, respectively, for the entire buildings compound and the individual structural units located in the corner and intermediate positions, in order to evaluate the beneficial or detrimental aggregate effect on the seismic behavior of individual constructions examined.

In this paper, seismic vulnerability and risk assessment of two samples of churches, located in Teramo and Ischia island (Naples gulf), both affected by the most recent earthquakes that occurred in Italy, are presented. To this aim, we applied a simplified method particularly suitable for seismic evaluations at a territorial scale, providing a global resulting score to be compared among the cases analyzed. The data obtained allowed us to provide vulnerability maps and a seismic risk index for all the considered churches. In addition, the calculated indexes permit a preliminary health state evaluation of the inspected churches, for ranking the priorities and planning additional in-depth evaluations.

The goal of this work is the assessment of the seismic vulnerability of building clusters within the historical center of Arsita (Teramo, Italy), damaged by the 2009 L'Aquila earthquake, by comparing two different analysis procedures applied to a construction compound case study. First, the seismic vulnerability of structural units of the building compound, has been appraised using a vulnerability evaluation quick form, appropriately conceived for masonry clusters. In particular, heading and intermediate structural units, having different geometrical configuration and seismic behaviors, have been inspected using the aforementioned form, which allowed for the calculation of a synthetic vulnerability index. Starting from these indices, the probable damage suffered by the examined structural units under different grade earthquakes, have been estimated. Later, both the single structural units and the whole construction compound were modeled using the macro-element refined method provided by the 3Muri non-linear analysis software. Static non-linear analyses performed on the above-mentioned structures have provided related pushover curves, used to estimate, using the N2 method, the damage suffered under seismic actions expected at that site. Therefore, the damage of single structural units have been compared to those experienced by the same structures within the building aggregate. Finally, the results derived from the two analysis methodologies considered were compared, confirming the effectiveness of the simplest technique to predict the seismic damage and vulnerability of investigated structures.

The Italian territory is rich of constructions belonging to the architectural heritage which deserve to be protected against earthquakes. In seismic prone areas ecclesiastic complexes, including churches, bell towers, monasteries, basilicas, synagogues, cathedrals and so on, have shown to be very susceptible at damage, even with partial or total collapses, when undergoing earthquakes. Indeed, these constructions, which are usually designed to withstand gravity loads only, are characterized by slender walls, lack of horizontal floors, bad quality of the masonry apparatus, ineffective connections among walls and between roofs and walls and absence of tie-beams absorbing the thrusts of arches and vaults. All these issues are responsible of the damages suffered by these structures, as detected after the last Italian earthquakes, such as those occurred in L'Aquila (2009), Emilia-Romagna (2012), Central Italy (2016), and Ischia (2017). In the current paper the seismic vulnerability assessment of the bell tower of the SS. Rosario ecclesiastic complex in Finale Emilia (district of Modena, Italy) is presented and discussed. After the geometrical and structural surveys of the whole masonry structure have been performed, the global seismic analysis of the bell tower by the 3Muri analysis software has been done. In particular, the behavioral differences between the isolate condition of the tower and the case within the ecclesiastic complex have been highlighted, showing the aggregate beneficial effect. Finally, proper retrofitting interventions have been designed and applied to the masonry bell tower, considered both as isolate construction and aggregate one, and the different benefits deriving from these interventions in the two inspected cases have been emphasized.

Italian buildings are mainly represented by unreinforced masonry (URM) constructions, which were mostly built before 1970, often without respecting seismic design criteria. The main objective of Italian designers is, therefore, to retrofit these buildings in order to improve their safety under earthquake, as well as to preserve the memory of the ancient building art. In addition, the assessment of the building energetic efficiency is nowadays a very pressing need for designers and practitioners. Energetic efficiency represents the capacity to optimize the consumption of energy resources in order to reach prefixed requirements for the environment protection. This paper shows both seismic and energetic retrofitting interventions on a residential URM building typical of the constructive practice in the South Italy. Initially, the building characterization under geometrical and structural viewpoints is done. Subsequently, the seismic vulnerability verification is performed with unsatisfactory results, so requiring upgrading or retrofitting interventions. Moreover, with the aim to increase living comfort and energy efficiency, energetic upgrading interventions, aimed at decreasing the building transmittance, are proposed. Seismic and energetic interventions are then computed from the economic point of view in order to evaluate the financial contributions foreseen by the Italian 2018 Balance Law through the Sismabonus and Ecobonus tools, respectively. Finally, the study proposes a global performance index able to take into account contemporary the seismic, energetic, and economic benefits deriving from retrofitting interventions applied on the inspected residential building.

In this paper, various moment-resisting steel frames (MRSFs) are subjected to 30 narrow-band motions scaled at different ground motion intensity levels in terms of spectral acceleration at first mode of vibration SaT1 in order to perform incremental dynamic analysis for peak and residual interstory drift demands. The results are used to compute the structural reliability of the steel frames by means of hazard curves for peak and residual drifts. It is observed that the structures exceed the threshold residual drift of 0.5%, which is perceptible to human occupants, and it could lead to human discomfort according to recent investigations. For this reason, posttensioned connections (PTCs) are incorporated into the steel frames in order to improve the structural reliability. The results suggest that the annual rate of exceedance of peak and residual interstory drift demands are reduced with the use of PTC. Thus, the structural reliability of the steel frames with PTC is superior to that of the MRSFs. In particular, the residual drift demands tend to be smaller when PTCs are incorporated in the steel structures.

The present research paper properly focuses on the dynamics and failure mechanisms of the masonry “Apennine Church” of Santissimo Crocifisso in Pretare, municipality of Arquata del Tronto in the province of Ascoli Piceno (Marche region, Central Italy). Such a peculiar structural type traditionally characterizes the intense seismic area of Central Italy, unfortunately almost totally damaged by the recent shock sequence of 2016. Advanced numerical modeling through discontinuous and continuous approaches were here utilized to have an insight into the dynamic properties and behavior of the structure under strong nonlinear dynamic excitations. In the discrete element approach, the non-smooth contact dynamics method, implemented in LMGC90©, was applied, adopting a full 3D detailed discretization. The church was schematized as an arrangement of rigid blocks, subjected to sliding by friction and perfect plastic collisions, with a null restitution coefficient. In the finite element approach, the concrete damaged plasticity model available in Midas FEA NX© was involved. This model allows reproducing the tensile cracking, the compressive crushing, and the degradation of the material under cyclic loads. Finally, the numerical analyses provided a valuable picture of the actual behavior of the church, thus giving useful hints for future strengthening interventions.

The present research aims to estimate the influence of site amplification on the seismic vulnerability of the historical centre of the municipality of Baranello in the Molise Region of Italy. Firstly, a structural and typological characterization of the investigated area has been done according to the EMS-98 scale. Subsequently, the vulnerability assessment of the historical buildings located there has been carried out through an appropriate survey form in order to identify the buildings which are most susceptible to seismic damage. To this purpose, the seismic event occurring in October of 2002 has been selected as a reference earthquake. Moreover, according to the AeDES form implemented by the Italian Civil Protection Department to evaluate the usability of constructions after seismic events, the calibration of the typological vulnerability curves of the built-up area has been done, and a quantitative assessment of the local seismic response has been achieved, based on the seismic motions recorded after the 2002 Molise earthquake. Finally, the local amplification factor, which negatively influences the severity of the seismic damage on the structures, has been taken into account in order to more correctly foresee the expected damage of the inspected urban sector, so as to use more appropriately the achieved results for reliable seismic risk mitigation plans.

The large-scale seismic risk assessment is a crucial point for safeguarding people and planning adequate mitigation plans in urban areas. The current research work aims at analysing a sector of the historic centre of Senerchia, located in the province of Avellino, in order to assess the seismic vulnerability and damage of old masonry building compounds. First, the typological classification of the inspected building aggregates is developed using the CARTIS form developed by the PLINIVS research centre in collaboration with the Italian Civil Protection Department. The global seismic vulnerability assessment of the building sample is carried out using the macroseismic method according to the EMS-98 scale in order to identify the buildings most susceptible to seismic damage. Furthermore, 12 damage scenarios are developed by means of an appropriate seismic attenuation law. Finally, the expected damage scenarios considering the local hazard effects induced are developed in order to evaluate the damage increment, averagely equal to 50%, due to the seismic amplification of different soil categories.

The proposed study aims at analysing a sub-urban sector in the historic centre of Qualiano, located in the province of Naples (Italy), in order to assess the seismic vulnerability of the main typology classes (masonry and reinforced concrete) in the study area and the consequent expected damage scenarios. The typological and structural characterisation of the investigated area is done through the CARTIS form developed by the PLINIVS research centre together with the Italian Civil Protection Department. Subsequently, the vulnerability simulation analysis is carried out by means of a quick methodology integrated into a GIS tool in order to identify the structural units (S.U.) most susceptible at damage under seismic events. Furthermore, in order to take into account the possible damage scenarios, a parametric analysis is performed using a seismic attenuation law in order to obtain the maximization of the expected urban losses. Finally, the site and topographical local conditions, which negatively influence the severity of the seismic damage on the structures, have been taken into account in order to more correctly foresee the expected damage of the inspected sub-urban sector to be used for appropriate seismic risk mitigation plans.