Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)最新文献

{"title":"STATE-DEPENDENT VULNERABILITY OF CASE-STUDY REINFORCED CONCRETE FRAMES","authors":"Karim Aljawhari, F. Freddi, C. Galasso","doi":"10.7712/120119.7102.19550","DOIUrl":"https://doi.org/10.7712/120119.7102.19550","url":null,"abstract":"This study investigates the effect of mainshock-aftershock sequences on numerical fragility and \u0000vulnerability relationships of European reinforced concrete (RC) moment-resisting frames \u0000(MRFs). A four-story, four-bay nonductile RC MRF is selected for illustrative purposes. This \u0000index building is representative of a typical vulnerability class in the Mediterranean region. \u0000The influence of the masonry infills on seismic performance is also investigated. An advanced \u0000numerical nonlinear model is developed for the case-study frame and then assessed through \u0000nonlinear dynamic analysis using both real and artificial mainshock-aftershock sequences, via \u0000a ‘sequential cloud’ approach. The obtained seismic demand estimates allow to generate fragility functions for the undamaged frame when subjected to mainshocks only. Moreover, statedependent fragility functions are derived for the mainshock-damaged frame when subsequently \u0000subjected to aftershocks. Damage-to-loss models, specifically calibrated on Italian post-earthquake data, are used to derive vulnerability functions for this case-study structure. Preliminary \u0000results from the study show that the frame experiences severe damages states and high losses \u0000for a range of ground-motion shaking intensities, with a clear damage increase due to aftershocks. An attempt to generate vector-valued mainshock-aftershock vulnerability relationships \u0000is finally presented. The proposed vulnerability surfaces can be more easily implemented into \u0000a time-dependent risk assessment framework.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"36 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132792508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DAMAGE DETECTION OF MIXED CONCRETE/STEEL FRAME SUBJECTED TO EARTHQUAKE EXCITATION","authors":"Nikos G. Pnevmatikos, B. Blachowski, G. Papavasileiou","doi":"10.7712/120119.7068.18916","DOIUrl":"https://doi.org/10.7712/120119.7068.18916","url":null,"abstract":"This paper deals with the application of wavelet analysis on damage detection in mixed concrete/steel frame structures subjected to earthquake excitation. Such buildings are typically the result of a building initially constructed as a reinforced concrete building and, at a later time, more storeys were added as steel moment resisting frames. These structures consist of reinforced concrete frames at the lower storeys and steel frames at the upper storeys. They are characterized by the material inconsistency in height. The proposed method of wavelet analysis of structural response is an output-only damage detection method. Non-linear dynamic analysis has been performed and response data at each story are obtained which are used as simulation data. Damage in the frame is due to hysteretic behaviour of columns and beams. Since the dynamic behaviour of an inelastic structure subjected to an earthquake excitation is a nonstationary process, discrete and continuous wavelet analysis were performed in order to retrieve the simulation response data. The proposed method is based on the assumption that there is a correlation between structural damage, due to non-linear behaviour of structural elements and spikes that can be clearly detected in the wavelet details. This is supported by the fact that at the time when the spikes are recorded, structural damage occurs as well. The numerical results indicate that the discrete wavelet analysis is a promising method for the detection of damage in structures without the need for visual inspection","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"195 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115643357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"NUMERICAL MODELS FOR SIMULATING THE DYNAMIC BEHAVIOUR OF FREESTANDING ANCIENT COLUMNS","authors":"Daniele Baraldi, G. Milani, V. Sarhosis","doi":"10.7712/120119.7016.19968","DOIUrl":"https://doi.org/10.7712/120119.7016.19968","url":null,"abstract":"In this contribution, three numerical models are considered and compared, with the main purpose of simulating the dynamic behavior of monolithic and multi-drum freestanding ancient stone columns. The behavior of such classical and historic structural elements, typical of the Mediterranean area and that are frequently subject to seismic actions, is characterized by a strong nonlinearity due to sliding and rocking. A simple and effective rigid beam model, able to numerically solve the equations of motion of the column also accounting for Housner’s hypotheses, is introduced for first and validated with respect to a software based on the Discrete Element Method (DEM), which has already proven its effectiveness in representing the behavior of columns and, more generally, masonry structures. Furthermore, a rigid block model accounting for the nonlinear behavior of the interfaces between the blocks is considered. On one hand, the rigid models can represent columns behavior with a not significant computational effort; on the other hand, the DEM is able to better describe the strong nonlinearity of columns behavior, with the detection of new contacts and the results in terms of collapse mechanisms characterized by large displacements that may be experienced by the blocks during the dynamic excitations. In this contribution several preliminary comparisons between the models are carried on by considering a multi-drum column and an equivalent monolithic one subject to a set of harmonic excitations with varying input frequency and acceleration amplitude.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130217168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"COMPARISON OF EXPERIMENTAL AND ANALYTICALLY PREDICTED OUT-OF-PLANE BEHAVIOR OF FRAMED-MASONRY WALLS CONTAINING OPENINGS","authors":"Filip Anić, D. Penava, Dalibor Burilo, L. Abrahamczyk, V. Sarhosis","doi":"10.7712/120119.7086.18574","DOIUrl":"https://doi.org/10.7712/120119.7086.18574","url":null,"abstract":". During an earthquake, structures are loaded in both in-plane and out-of-plane direc-tion. This paper investigates the behaviour of load-bearing frames with infill walls that contain openings. As when they are subjected to out-of-plane, inertial loads. In the experimental cam-paigns of like structures, it was found that even with openings, the beneficial arching-action was able to develop. However, its effectiveness was limited. Namely, the deformation capabilities in all cases were significantly lowered. Same can not be stated for the load-bearing capacities, as some researches found no reduction while others did. Additionally, this paper analyses the existing equations that can calculate the load-bearing capacity of such structures. Low corre-lations were found between the experimental and analytical capacities. Hence, further research endeavours should be addressed in order to gain a reliable analytical model","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121385725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"THE SEISMIC PERFORMANCE OF STEEL BUILDINGS RETROFITTED WITH STEEL CABLES AGAINST PROGRESSIVE COLLAPSE","authors":"G. Papavasileiou, Nikos G. Pnevmatikos","doi":"10.7712/120119.7067.18826","DOIUrl":"https://doi.org/10.7712/120119.7067.18826","url":null,"abstract":"","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123584279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"REGIONAL-SCALE SEISMIC FRAGILITY ASSESSMENT BASED ON GAUSSIAN PROCESS REGRESSION","authors":"R. Gentile, C. Galasso","doi":"10.7712/120119.7032.19782","DOIUrl":"https://doi.org/10.7712/120119.7032.19782","url":null,"abstract":"Seismic fragility assessment of building portfolios usually involves empirical approaches, or \u0000numerical, mechanics-based approaches applied to properly-sampled index buildings representative of defined structural classes. These approaches often neglect the effect of class variability on portfolio seismic risk estimates. Alternatively, metamodeling techniques can be \u0000adopted to surrogate complex mechanical analyses and to properly include class variability. \u0000However, commonly-used metamodels require the a priori definition of the functional form for \u0000the fitting and they quantify the uncertainty on the predictions of the output (e.g., fragility as a \u0000function of the geometry of a building) based on simplifying assumptions. In this study, Gaussian process regression is adopted to address these limitations. The proposed method is demonstrated for seismically-deficient RC school buildings with construction details typical of some \u0000developing countries (e.g., in Southeast Asia), for which real data is available. Gaussian processes estimating the fragility statistics of such schools are fitted based on thousands non-linear \u0000time-history analyses for over 100 building realisations within the structural class. To further \u0000increase the tractability of the methodology, alternative metamodels are defined based on numerical non-linear static (pushover) analyses or analytical “by hand pushover” through the \u0000Simple Lateral Mechanism Analysis (SLaMA) method. Four validation structures (outside the \u0000training set) are defined and analysed through the same approaches. Preliminary results from \u0000this study show predicted-to-“observed” errors below 10%, highlighting the accuracy of the \u0000fitted metamodels. Moreover, non-linear static approaches (SLaMA or numerical pushover), \u0000coupled with the capacity spectrum method, produce sound results, drastically reducing the \u0000computational burden in the model calibration.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133370795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IDENTIFYING UNCERTAINTY CONTRIBUTIONS TO THE SEISMIC FRAGILITY ASSESSMENT OF A NUCLEAR REACTOR STEAM LINE","authors":"P. Gehl, Marine Macilhac-Fradin, J. Rohmer, Y. Guigueno, N. Rahni, J. Clément","doi":"10.7712/120119.7312.18915","DOIUrl":"https://doi.org/10.7712/120119.7312.18915","url":null,"abstract":"In nuclear applications, fragility curves are an essential element of the seismic probabilistic safety assessment that is performed at the level of the power plant. These statistical tools establish the link between the probabilistic seismic hazard loading at the site and the required performance of the plant's safety functions. In this context, the fragility model formalized by Kennedy & Ravindra (1984) proposes to account for the aleatory randomness and the epistemic uncertainty generated by various sources of variability, such as the representation of the seismic input or the assumptions in the structural model and in the loading patterns. Therefore, this study investigates the relative contributions of such variables to the dispersion of the resulting fragility functions, while ensuring the separation between aleatory and epistemic uncertainty sources, as advocated by the standards in effect in the nuclear industry. To this end, a coupled model of a supporting structure and an anchored steam line is considered and computed with the finite-element CAST3M software (Rahni et al., 2017). The failure criterion is related to the exceedance of a given effort value at a point of the steam line corresponding to a vertical stop. A coupled of hundreds of three-component ground-motion records are applied at the base of the model, in order to perform non-linear time-history analyses. The record selection follows the conditional spectrum method (Lin et al., 2013), in order to scale the records while ensuring the hazard consistency, through the identification of reference earthquake scenarios for each predefined hazard level. As a result, dozens of ground-motion parameters are tested as potential intensity measures (IMs), with respect to state-of-the-art indicators measuring efficiency or sufficiency. Some couples of ground-motion parameters are assembled as vector-valued IMs, in order to generate so-called fragility surfaces: these multi-variate functions may then be reinterpreted as single-IM fragility curves, where the conditional distribution of the secondary IM with respect to the main one generates additional confidence intervals for the fragility curve. It is thus shown that the aleatory randomness due to record-to-record variability may be partially transferred to an epistemic uncertainty contribution. This variability is then put in perspective with other sources of uncertainty due to modelling assumptions, such as the variability in the mechanical parameters of the model or the angle of loading of the seismic input.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"77 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129478682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ON THE SOLITARY WAVE DYNAMICS OF TENSEGRITY LATTICES WITH STIFFENING RESPONSE: A NUMERICAL STUDY","authors":"A. Micheletti, G. Ruscica, A. Amendola, Ida Mascolo, F. Fraternali","doi":"10.7712/120119.7019.18382","DOIUrl":"https://doi.org/10.7712/120119.7019.18382","url":null,"abstract":"We present some peculiar results about the solitary-wave dynamics of novel tensegrity-based metamaterials. It has been previously shown that one-dimensional chains of triangu-lar tensegrity prisms with stiffening behavior support the propagation of compressive solitarywaves. We show that such result can be generalized to two-dimensional and three-dimensionalmodular tensegrity lattices composed of polygonal and polyhedral units. Differently from theone-dimensional case, the stiffening response of these lattices originates at the interface be-tween adjacent units, not from the unit themselves. We present numerical results on the responseto impulsive loads of slender assemblies composed by square units in two-dimensions, and cu-bic units in three-dimensions. We observed compact compressive waves forming at impactlocations, together with localized thermalization effects. Such compact waves propagate withnearly constant speed and energy, while maintaining their shape, and emerge from collisionwith other compact waves almost unaltered, losing a small fraction of their energy. These re-sults suggest the investigation of the dynamics of regular and quasi-regular tessellations formedby other types of polygonal and polyhedral units.","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115747213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"QUASI-STATIC CORRECTION OF MODALLY REDUCED ORDER MODELS FOR SYSTEM INVERSION IN STRUCTURAL DYNAMICS","authors":"K. Maes, Freddie Karlsson, G. Lombaert","doi":"10.7712/120119.7235.19508","DOIUrl":"https://doi.org/10.7712/120119.7235.19508","url":null,"abstract":"","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117170963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ON THE USE OF META-FOUNDATIONS FOR SEISMIC ISOLATION: A PRACTICAL APPLICATION FOR CONVENTIONAL BUILDINGS","authors":"Panagiotis Martakis, Vasileios Ntertimanis, E. Chatzi","doi":"10.7712/120119.7307.19947","DOIUrl":"https://doi.org/10.7712/120119.7307.19947","url":null,"abstract":"","PeriodicalId":414988,"journal":{"name":"Proceedings of the 7th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COMPDYN 2015)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133962245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}