D. Grecea | Politehnica University of Timisoara (original) (raw)
Papers by D. Grecea
New concepts, applications and challenges, 2013
Procedia Engineering, 2016
The Romanian existing building stock of collective dwellings is in a vast majority composed of re... more The Romanian existing building stock of collective dwellings is in a vast majority composed of reinforced concrete large prefabricated panel blocks of flats, erected during Communism. According to the 1992 Census, these standardized and widespread buildings housed almost 60 percent of the urban population of the country. Due to the small, inflexible apartments on one hand and the changing living conditions of the contemporary Romanian society on the other, a need for extending the inner surface of the existing flats has been identified. This situation led to the adoption of technically restrictive ground-floor spatial additions and other vernacular solutions that are being applied to upper stories, some of them not being able to provide, in many cases, any forms of long term structural guarantee to their users. The present paper describes a prefabricated steel structure solution for cantilevered apartment extensions that can be independently attached to the façade, as well as some technical connecting details to the existing building. A global structural analysis performed on a virtual model depicting a widespread type of block of flats (Model 770) proves the non-intrusive influence the cantilevered apartment extensions have over the existing buildings, in multiple different scenarios of attachments. Moreover, a FEM analysis of the proposed details further shows the reliability of the examined solution.
New concepts, applications and challenges, 2013
New concepts, applications and challenges, 2013
ICSA 2010 - 1st International Conference on Structures & Architecture, July 21-23 July, 2010 in Guimaraes, Portugal, 2010
apcmr.britt.ro
The paper presents a new design methodology for MR steel frames based on three performance levels... more The paper presents a new design methodology for MR steel frames based on three performance levels (limit states). To illustrate the new methodology a parametrical study on new and existing steel frames is performed. Accelerations and q-factors for the three limit states are ...
This paper presents the experimental tests carried out on two types of elements subject to tensio... more This paper presents the experimental tests carried out on two types of elements subject to tension or compression, in order to verify the bearing capacity of high-strength bolt connections. The elements have been tested under gradually increasing static and pulsating oads. The experimental results rendered evident a good agreement with the theoretical values
Actual design codes and recommendations for ductile Moment Resisting Steel Frames in seismic zone... more Actual design codes and recommendations for ductile Moment Resisting Steel Frames in seismic zones require to beam-to-column joints to sustain a total rotation of 0.035 rad (in Europe) to 0.040 rad (in United States). The problem is that in codes, there are no analytical methods to predict the rotation capacity of MR connections, not even for monotonic loading, which is simpler then compared with seismic action of cyclic type. Even if last years appeared some proposals for analytical or numerical based methods to evaluate rotation procedure for their qualification in terms of ductility, still remain the prequalification tests, both for static and seismic actions. In the present paper, based on extended experimental studies, comparatively conducted under monotonic and cyclic loading on different types of connections, both for steel and composite MR frames, a reduction factor to be applied to monotonic rotation capacity is proposed in the purpose of evaluation of cyclic rotation capac...
Behaviour of Steel Structures in Seismic Areas, 2021
En se basant sur une approche a l'aide d'analyses dynamiques non lineaires, on explique p... more En se basant sur une approche a l'aide d'analyses dynamiques non lineaires, on explique pourquoi la definition usuelle du facteur de comportement q adoptee dans la litterature n'est pas la plus appropriee, conduisant en particulier a sous-evaluer l'effort de cisaillement a la base de la structure et par consequent les efforts internes dans celle-ci. Une nouvelle definition du facteur q est proposee, qu'il convient d'associer a une valeur precise d'acceleration nominale du site. La verification de la resistance globale de la structure peut etre effectuee a l'aide de plusieurs analyses statiques equivalentes de type rigide-plastique, eventuellement au 2 eme ordre geometrique lorsque la structure est apte a etre pleinement dissipative. Un exemple de portique a 6 etages et 3 travees est presente brievement pour illustrer ces nouveaux concepts.
The Romanian existing building stock of collective dwellings is in a vast majority composed of re... more The Romanian existing building stock of collective dwellings is in a vast majority composed of reinforced concrete large prefabricated panel blocks of flats, erected during Communism. According to the 1992 Census, these standardized and widespread buildings housed almost 60 percent of the urban population of the country. Due to the small, inflexible apartments on one hand and the changing living conditions of the contemporary Romanian society on the other, a need for extending the inner surface of the existing flats has been identified. This situation led to the adoption of technically restrictive ground-floor spatial additions and other vernacular solutions that are being applied to upper stories, some of them not being able to provide, in many cases, any forms of long term structural guarantee to their users. The present paper describes a prefabricated steel structure solution for cantilevered apartment extensions that can be independently attached to the façade, as well as some technical connecting details to the existing building. A global structural analysis performed on a virtual model depicting a widespread type of block of flats (Model 770) proves the non-intrusive influence the cantilevered apartment extensions have over the existing buildings, in multiple different scenarios of attachments. Moreover, a FEM analysis of the proposed details further shows the reliability of the examined solution.
The Paramount Role of Joints into the Reliable Response of Structures, 2000
New concepts, applications and challenges, 2013
Procedia Engineering, 2016
The Romanian existing building stock of collective dwellings is in a vast majority composed of re... more The Romanian existing building stock of collective dwellings is in a vast majority composed of reinforced concrete large prefabricated panel blocks of flats, erected during Communism. According to the 1992 Census, these standardized and widespread buildings housed almost 60 percent of the urban population of the country. Due to the small, inflexible apartments on one hand and the changing living conditions of the contemporary Romanian society on the other, a need for extending the inner surface of the existing flats has been identified. This situation led to the adoption of technically restrictive ground-floor spatial additions and other vernacular solutions that are being applied to upper stories, some of them not being able to provide, in many cases, any forms of long term structural guarantee to their users. The present paper describes a prefabricated steel structure solution for cantilevered apartment extensions that can be independently attached to the façade, as well as some technical connecting details to the existing building. A global structural analysis performed on a virtual model depicting a widespread type of block of flats (Model 770) proves the non-intrusive influence the cantilevered apartment extensions have over the existing buildings, in multiple different scenarios of attachments. Moreover, a FEM analysis of the proposed details further shows the reliability of the examined solution.
New concepts, applications and challenges, 2013
New concepts, applications and challenges, 2013
ICSA 2010 - 1st International Conference on Structures & Architecture, July 21-23 July, 2010 in Guimaraes, Portugal, 2010
apcmr.britt.ro
The paper presents a new design methodology for MR steel frames based on three performance levels... more The paper presents a new design methodology for MR steel frames based on three performance levels (limit states). To illustrate the new methodology a parametrical study on new and existing steel frames is performed. Accelerations and q-factors for the three limit states are ...
This paper presents the experimental tests carried out on two types of elements subject to tensio... more This paper presents the experimental tests carried out on two types of elements subject to tension or compression, in order to verify the bearing capacity of high-strength bolt connections. The elements have been tested under gradually increasing static and pulsating oads. The experimental results rendered evident a good agreement with the theoretical values
Actual design codes and recommendations for ductile Moment Resisting Steel Frames in seismic zone... more Actual design codes and recommendations for ductile Moment Resisting Steel Frames in seismic zones require to beam-to-column joints to sustain a total rotation of 0.035 rad (in Europe) to 0.040 rad (in United States). The problem is that in codes, there are no analytical methods to predict the rotation capacity of MR connections, not even for monotonic loading, which is simpler then compared with seismic action of cyclic type. Even if last years appeared some proposals for analytical or numerical based methods to evaluate rotation procedure for their qualification in terms of ductility, still remain the prequalification tests, both for static and seismic actions. In the present paper, based on extended experimental studies, comparatively conducted under monotonic and cyclic loading on different types of connections, both for steel and composite MR frames, a reduction factor to be applied to monotonic rotation capacity is proposed in the purpose of evaluation of cyclic rotation capac...
Behaviour of Steel Structures in Seismic Areas, 2021
En se basant sur une approche a l'aide d'analyses dynamiques non lineaires, on explique p... more En se basant sur une approche a l'aide d'analyses dynamiques non lineaires, on explique pourquoi la definition usuelle du facteur de comportement q adoptee dans la litterature n'est pas la plus appropriee, conduisant en particulier a sous-evaluer l'effort de cisaillement a la base de la structure et par consequent les efforts internes dans celle-ci. Une nouvelle definition du facteur q est proposee, qu'il convient d'associer a une valeur precise d'acceleration nominale du site. La verification de la resistance globale de la structure peut etre effectuee a l'aide de plusieurs analyses statiques equivalentes de type rigide-plastique, eventuellement au 2 eme ordre geometrique lorsque la structure est apte a etre pleinement dissipative. Un exemple de portique a 6 etages et 3 travees est presente brievement pour illustrer ces nouveaux concepts.
The Romanian existing building stock of collective dwellings is in a vast majority composed of re... more The Romanian existing building stock of collective dwellings is in a vast majority composed of reinforced concrete large prefabricated panel blocks of flats, erected during Communism. According to the 1992 Census, these standardized and widespread buildings housed almost 60 percent of the urban population of the country. Due to the small, inflexible apartments on one hand and the changing living conditions of the contemporary Romanian society on the other, a need for extending the inner surface of the existing flats has been identified. This situation led to the adoption of technically restrictive ground-floor spatial additions and other vernacular solutions that are being applied to upper stories, some of them not being able to provide, in many cases, any forms of long term structural guarantee to their users. The present paper describes a prefabricated steel structure solution for cantilevered apartment extensions that can be independently attached to the façade, as well as some technical connecting details to the existing building. A global structural analysis performed on a virtual model depicting a widespread type of block of flats (Model 770) proves the non-intrusive influence the cantilevered apartment extensions have over the existing buildings, in multiple different scenarios of attachments. Moreover, a FEM analysis of the proposed details further shows the reliability of the examined solution.
The Paramount Role of Joints into the Reliable Response of Structures, 2000