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The purpose of this paper is to present a simplified hybrid modeling (HYMOD) approach which overcomes limitations regarding computational cost and permits the simulation and prediction of the nonlinear inelastic behavior of full-scale RC structures.

The proposed HYMOD formulation was integrated in a research software ReConAn FEA and was numerically studied through the use of different numerical implementations. Then the method was used to model a full-scale two-storey RC building, in an attempt to demonstrate its numerical robustness and efficiency.

The numerical results performed demonstrate the advantages of the proposed hybrid numerical simulation for the prediction of the nonlinear ultimate limit state response of RC structures.

A new numerical modeling method based on finite element method is proposed for simulating accurately and with computational efficiency, the mechanical behavior of RC structures. Currently 3D detailed methods are used to model single structural members or small parts of RC structures. The proposed method overcomes the above constraints.

The purpose of this paper is to present integrated methodologies based on multilevel modelling concepts for finite element analysis (FEA) of reinforced concrete (RC) shell structures, with specific reference to account for the nonlinear behaviour of cracked concrete and the other associated features.

Geometric representation of the shell is enabled through multiple concrete layers. Composite characteristic of concrete is accounted by assigning different material properties to the layers. Steel reinforcement is smeared into selected concrete layers according to its position in the RC shell. The integrated model concurrently accounts for nonlinear effects due to tensile cracking, bond slip and nonlinear stress‐strain relation of concrete in compression. Smeared crack model having crack rotation capability is used to include the influence of tensile cracking of concrete. Propagation and change in direction of crack along thickness of shell with increase in load and deformation are traced using the layered geometry model. Relative movement between reinforcing steel and adjacent concrete is modelled using a compatible bond‐slip model validated earlier by the authors. Nonlinear iterative solution technique with imposed displacement in incremental form is adopted so that structures with local instabilities or strain softening can also be analysed.

Proposed methodologies are validated by evaluating ultimate strength of two RC shell structures. Nonlinear response of McNeice slab is found to compare well with that of experiment available in literature. Then, a RC cooling tower is analysed for factored wind loads to study its behaviour near ultimate load. Numerical validation demonstrates efficacy and usefullness of the proposed methodologies for nonlinear FEA of RC shell structures.

The present paper integrates critical methodologies used for behaviour modelling of concrete and reinforcement with the physical interaction among them. The study is unique by considering interaction of tensile cracking and bond‐slip which are the main contributors to nonlinearity in the nonlinear response of RC shell structures. Further, industrial application of the proposed modelling strategy is demonstrated by analysing a RC cooling tower shell for its nonlinear response. It is observed that the proposed methodologies in the integrated manner are unique and provide stability in nonlinear analysis of RC shell structures.

The present article aims to investigate the quality of the relationships in a business partnership for a project in Medtech field and the components that most influence them, with special attention to relational capabilities (RCs). Dyadic relationships and mainly RCs are considered critical factors for the success of a partnership.

A case study was used to evaluate the influence of RC on the progress of an alliance between a start-up and a small and medium scale enterprise (SME). The evaluation is performed using a questionnaire. To highlight such progress, the same questions were asked at the start of the partnership and one year later. The results were compared to analyse the improvement of RC and draw conclusions on the correlation between RC and alliance performance.

The method adopted allowed for a clear identification of the criticalities of the partnership. The authors found evidence that poor RCs lead to confusion, a sense of exclusion and a lack of collaboration amongst members. Results confirmed that increased RC and aligning the allies' capabilities positively affect the alliance's performance.

Exogenous variables influencing the partnership's progress were not included in the present study. Future research may consider them.

Limited prior research is available on collaboration between SME and start-ups. The present authors aim to investigate the topic further, investigating RCs between firms. The article is also a starting point for future case study comparisons.

RC columns are very susceptible to fire, as besides the detrimental effects due to this action, second‐order effects play a significant role. In this work, the aim is to consider the ISO834 standard fire, and the focus is put on checking the proper use of a simplified method suggested on Annex B.3 of EC2 to account for the second‐order effects in RC columns.

The use of Annex B.3 of EC2 is obscure in what concerns the peak strain to be considered at the most deformed cross‐section concrete fibres, and this affects the evaluation of the second‐order moment installed in the RC column during the fire. Two hypotheses are analysed in the paper, and validated against the calculations from the advanced code SAFIR: the one where the classical limit of 3.5‰ is assumed for the peak concrete strain in compression, and a more refined compatibility of the section total strains.

The simulations demonstrate that using the simplified method with hypothesis H1 leads to unsafe conclusions. Conversely, hypothesis H2 compares much better with SAFIR predictions, and it can be rather easily adopted in real applications.

The indications provided here for the proper application of the simplified method are very useful for practical use. They overcome an unclear aspect on its implementation, not yet previously addressed.

In civil engineering construction, the reinforced concrete (RC) structure is generally used and exposed to fatigue loading as it is in service. The assessment of the RC structure is required to maintain the service life of the structure.

This paper presents the behaviour of RC beam specimens under increasing maximum fatigue loading until failure. Simultaneously the acoustic emission (AE) was recorded. Twelve phases of maximum fatigue loading at Stage 1 and Stage 2 were applied to the beam with the frequency of 1 Hz and 5,000 load cycles were applied for each load phase. Two AE parameters were analysed and discussed, namely average frequency and rise angle value at CH4 and CH5.

The results found that the load and crack are closely related to the AE activities in the RC beam specimen when subjected to increasing fatigue loading.

To investigate the AE characteristics of RC beam specimens subjected to 12 phases of maximum fatigue loading using the average frequency and rise angle value.

Approaches the shakedown optimal design of reinforced concrete (RC) structures, subjected to variable and repeated external quasi‐static actions which may generate the well‐known shakedown or adaptation phenomenon, when constraints are imposed on deflection and/or deformation parameters, in order to simulate the limited flexural ductility of the material, in the presence of combined axial stress and bending. Within this context, the classical shakedown optimal design problem is revisited, using a weak upper bound theorem on the effective plastic deformations. For this problem a new computational algorithm, termed evolution strategy, is herein presented. This algorithm, derived from analogy with the biological evolution, is based on random operators which allow one to treat the areas of steel reinforcements at each RC cross‐section of the structure as design variables of discrete type, and to use refined non‐linear approximations of the effective bending moment – axial force M‐N interaction diagrams of each RC cross‐section. The results obtained from case studies available in the literature show the advantages of the method and its effectiveness.

In the absence of random variables, random variables are generated by the Monte Carlo (MC) simulation method. There are some methods for generating fragility curves with fewer nonlinear analyses. However, the accuracy of these methods is not suitable for all performance levels and peak ground acceleration (PGA) range. This paper aims to present a method through the seismic improvement of the high-dimensional model representation method for generating fragility curves while taking advantage of fewer analyses by choosing the right border points.

In this method, the values of uncertain variables are selected based on the results of the initial analyses, the damage limit of each performance level or according to acceptable limits in the design code. In particular, PGAs are selected based on the general shape of the fragility curve for each performance limit. Also, polynomial response functions are estimated for each accelerogram. To evaluate the accuracy, fragility curves are estimated by different methods for a single degree of freedom system and a reinforced concrete frame.

The results indicated that the proposed method can not only reduce the computational cost but also has a higher accuracy than the other methods, compared with the MC baseline method.

The proposed response functions are more consistent with the actual values and are also congruent with each performance level to increase the accuracy of the fragility curves.

This study aims to discuss the causes of short-lived structuring of contemporary buildings. The life expectancy of structures may be theoretically predefined during the state of the design. This time period, known as the service life of structures, is determined by the load or the deformation level at which irreversible failures of the bearing structure may occur. On the other hand, planned obsolescence and perceived obsolescence, observed in the western world since the first half of 20th century, are currently setting an economic reality and are part of an expanded framework that, apart from architectural structures, extends to all design fields. The effects of short-lived structuring on environmental and energy terms are presented and theoretical and experimental recommendations from the literature are cited, as well as recommendations that have already been successfully applied in some countries.

This study aims to discuss the issues associated with short-lived structuring, durability and obsolescence of contemporary structures. For this purpose, theoretical and experimental recommendations from the literature are cited, via an extensive state of the art research.

Short-lived structuring has been a field of research during recent years. Terms such as durability are being introduced into Design Codes, while trends like perceived obsolescence and environmental impact raise issues for research. Moreover, the results of short-lived structuring are becoming more and more apparent, indicating an unsustainable reality. Issues like maintenance of structures, sustainability in design, corrosion effects, repair techniques and building waste management are an important field of research among the engineering community. In this study, the parameters affecting the lifespan of contemporary structures have been discussed.

The effects of short-lived structuring on environmental and energy terms are presented and theoretical and experimental recommendations from the literature are cited. The parameters studied herein concern material properties and design approach but also environmental and energy-related ones.

When a numerous amount of buildings was built in reinforced concrete, in a period when the regulations did not have the design philosophy for the occurrence of earthquakes, it is of extreme importance to carry out full and effective structural assessments, specially considering and comparing bare frame and infilled structure. The paper aims to discuss these issues.

Among several possibilities to make the evaluation as, simplified, linear analysis and static non-linear analysis, the non-linear dynamic can provide the most accurate numerical behaviour compared to the real one. The time-history non-linear analyses are developed on the software SeismoStruct for different levels of intensity. Local verifications are then applied separately from both Eurocode and Italian Code.

The application of validated models for the analysis of real buildings allows a complete seismic assessment. The level of uncertainty increases integrating particularities regarding the infill masonry walls. The paper shows important global and local seismic safety for these complex typology of buildings.

A representative common concrete structure without seismic provisions is first analysed and discussed in terms of global behaviour, deformations and progression of forces. The case study structure is considered both as bare structure and with integrated infill panels. It is also discussed in a local level, about brittle and ductile mechanisms, and extra comparisons between different interpretations of different standards. The case study structure is considered both as bare structure and with integrated infill panels.

The purpose of this paper is to contribute to the solution of the fatigue damage problem of reinforced concrete frames in bending.

The problem of fatigue damage is formulated based on the rheological–dynamical analogy, including a scalar damage variable to address the reduction of stiffness in strain softening. The modal analysis is used by the finite element method for the determination of modal parameters and resonance stability of the selected frame cross-section. The objectivity of the presented method is verified by numerical examples, predicting the ductility in bending of the frame whose basic mechanical properties were obtained by non-destructive testing systems.

The modal analysis in the frame of the finite element method is suitable for the determination of modal parameters and resonance stability of the selected frame cross-section. It is recommended that the modulus of elasticity be determined by non-destructive methods, e.g. from the acoustic response.

The paper presents a novel method of solving the ductility in bending taking into account both the creep coefficient and the aging coefficient. The rheological-dynamical analogy (RDA) method uses the resonant method to find material properties. The characterization of the structural damping via the damping ratio is original and effective.