scholarly journals Out-of-plane capacity of cladding panel-to-structure connections in one-story R/C precast structures

2020 ◽  
Vol 18 (15) ◽  
pp. 6849-6882
Author(s):  
Giovanni Menichini ◽  
Emanuele Del Monte ◽  
Maurizio Orlando ◽  
Andrea Vignoli

Abstract The interaction between cladding panels and the main structure is a crucial point to assess the seismic response, and above all the structural safety, of RC precast industrial building. In the past, connections were often designed to allow construction tolerances and to accommodate both thermal and wind-induced displacements. The lack of specific details to allow relative in-plane displacements between cladding panels and the main structure often led to the participation of cladding panels in the structure seismic-resistant system with consequent connection failures. In the last decades, a lot of experimental tests were performed to investigate the in-plane performance of panel connections, and some design recommendations have been developed accordingly. In the out-of-plane direction, the connections were often considered to be infinitely rigid and not to suffer any damage by the seismic load. This work deals with the out-of-plane response of panel-to-structure connections for vertical panels typical of industrial and commercial precast buildings. Both standard hammer-head strap and new devices, called SismoSafe, were investigated. Tests were performed in the Structures and Materials Testing Laboratory of the Department of Civil and Environmental Engineering of Florence, where a specific setup was designed to perform cyclic and monotonic tests on the connection devices. Standard connections showed a rather limited resistance, while the innovative connections exhibited a high out-of-plane resistance. Numerical analyses were also performed on a case study building to evaluate the distribution of the out-of-plane demand on the connections.

2021 ◽  
Vol 7 ◽  
Author(s):  
Michele Egidio Bressanelli ◽  
Marco Bosio ◽  
Andrea Belleri ◽  
Paolo Riva ◽  
Piergiovanni Biagiotti

The 2012 Emilia earthquakes caused significant damage to existing precast reinforced concrete (RC) industrial buildings not specifically designed to resist seismic actions. The main failure mechanisms were related to the loss of support of beams and roof elements caused by high relative displacements, to the failure of the mechanical connections and consequent fall of cladding panels, to the damage at the base of the columns and to the collapse of RC forks at the top of the columns. In all cases, the behavior of the connections, and specifically of beam-to-column connections, demonstrated to be crucial, given that they may inhibit the exploitation of strength and ductility reserves in precast elements. This paper presents a beam-to-column connection restraint-device for precast industrial buildings. The device can be applied to existing structures to transfer horizontal seismic forces between beams and columns and to increase the energy dissipation of the system. Design criteria were defined with the aim to limit the relative maximum displacement at the beam-to-column interface and to mitigate the out-of-plane overturning of the beam. Numerical analyses were carried out to define a suitable shape of the device and to investigate its effectiveness in terms of both local and global behavior. To validate the computational results, experimental tests have been also carried out. The tests allowed to classify the device as “dissipative” according to UNI EN 15129. Finally, the design procedure has been validated considering a one-story industrial building case study designed in accordance with the Italian building code.


Buildings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 400
Author(s):  
Liana Ostetto ◽  
Romain Sousa ◽  
Hugo Rodrigues ◽  
Paulo Fernandes

The latest earthquakes in Europe exposed some critical problems in the connections of cladding panels in industrial precast reinforced concrete (PRC) structures. These connections did not perform as desired, causing the panels to fall, leading to significant nonstructural damage that resulted in the loss of human life and significant socio-economic impacts due to the interruption of business. Furthermore, in addition to the behavior of the cladding system itself, it is still not clear to what extent it can influence the overall seismic performance of the main structure. Making use of a simplified macroelement, the present study assesses the seismic performance of commonly employed cladding-to-structure connections, as well as the interaction of cladding panels with industrial PRC buildings. The analyses were carried out considering a PRC building representative of a Portuguese industrial park, studied with and without cladding panels. The seismic behavior of the structure was assessed considering both nonlinear static and dynamic procedures.


2012 ◽  
Vol 256-259 ◽  
pp. 2229-2233
Author(s):  
Marco Valente

This study presents an innovative approach to enhance the seismic performance of precast structures. Friction devices were inserted at the beam-to-column connections with the aim of providing supplemental energy dissipation and structural drift control. A single-story industrial building and a multi-story frame were analyzed in this study to assess the effectiveness of the dissipative friction devices. A simplified model describing the hysteretic behaviour of the friction device was developed and parametric analyses were carried out in order to establish the optimum value of the plastic moment of the device for the different precast structures. The results of the numerical investigations showed that the installation of the friction devices caused a significant decrease of displacements at the top of the structures. The energy dissipation mostly concentrated in the devices and the plastic demand on structural members was considerably reduced, along with the potential for structural damage.


2021 ◽  
Vol 7 ◽  
Author(s):  
Lorenzo De Stefani ◽  
Roberto Scotta

Recent earthquakes in southern Europe highlighted that the connections of cladding panels to R.C. frames in precast buildings had a major role in the structural collapse. For this reason, there is an urgent need for a review of the design methods for these connections as well as for an improvement in the manufacturing technology. This article aimed to assess the efficiency of dissipative panel-to-structure and roof connections in R.C. precast buildings. A parametric study consisting of linear and non-linear analyses on one case-study building is performed. Different sensitivity analyses are performed varying their mechanical properties (i.e., stiffness, strength, and ductility) to analyze the behavior of the CP/frame connections. The study focuses on dissipative connections with an elastic–plastic behavior, placed between cladding panels (CPs) and frames in precast buildings with stacked horizontal cladding panels. The introduction of dissipative CP/frame connections implies the inclusion of panels in the global seismic resisting system. The “panels + frame” system highlights a high stiffness until the yield strength of the CP/frame connections is reached. The results, obtained from non-linear dynamic analyses (NLDAs), clearly show how the proposed connection improves the structural seismic performance. By contrast, this is no longer true for R.C. precast structures with flexible diaphragms, especially for intermediate columns, far from panels aligned to seismic action. In this case, significant and unexpected axial forces arise on out-of-plane connections between panels and columns. The integration of an efficient diaphragm is essential to prevent these critical issues both on intermediate columns and CP/column connections; it enables the dissipative capacity of the “panels + frame” system, and it significantly limits the forces and displacements of intermediate alignments. Unfortunately, the achievement of a rigid diaphragm is not always feasible in precast buildings. A possible alternative to activate dissipative capacities of the roof diaphragm with limited in-plane stiffness is the use of dissipative connections linking roof beams and main beams. The solutions described in this article can be applied both in the design of new buildings and for the seismic upgrading of existing ones with easy-to-install and low-impact applications.


Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 104
Author(s):  
Dong-Hyeop Kim ◽  
Young-Cheol Kim ◽  
Sang-Woo Kim

Airworthiness standards of Korea recommend verifying structural safety by experimental tests and analytical methods, owing to the development of analysis technology. In this study, we propose a methodology to verify the structural safety of aircraft components based on airworthiness requirements using an analytical method. The structural safety and fatigue integrity of a linear actuator for flap control of aircraft was evaluated through numerical analysis. The static and fatigue analyses for the given loads obtained from the multibody dynamics analysis were performed using the finite element method. Subsequently, the margin of safety and vulnerable area were acquired and the feasibility of the structural safety evaluation using the analytical method was confirmed. The proposed numerical analysis method in this study can be adopted as an analytical verification methodology for the airworthiness standards of civilian aircraft in Korea.


2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Izumi Nakamura ◽  
Akihito Otani ◽  
Masaki Shiratori

Pressurized piping systems used for an extended period may develop degradations such as wall thinning or cracks due to aging. It is important to estimate the effects of degradation on the dynamic behavior and to ascertain the failure modes and remaining strength of the piping systems with degradation through experiments and analyses to ensure the seismic safety of degraded piping systems under destructive seismic events. In order to investigate the influence of degradation on the dynamic behavior and failure modes of piping systems with local wall thinning, shake table tests using 3D piping system models were conducted. About 50% full circumferential wall thinning at elbows was considered in the test. Three types of models were used in the shake table tests. The difference of the models was the applied bending direction to the thinned-wall elbow. The bending direction considered in the tests was either of the in-plane bending, out-of-plane bending, or mixed bending of the in-plane and out-of-plane. These models were excited under the same input acceleration until failure occurred. Through these tests, the vibration characteristic and failure modes of the piping models with wall thinning under seismic load were obtained. The test results showed that the out-of-plane bending is not significant for a sound elbow, but should be considered for a thinned-wall elbow, because the life of the piping models with wall thinning subjected to out-of-plane bending may reduce significantly.


2011 ◽  
Vol 15 (9) ◽  
pp. 1319-1338
Author(s):  
Liberato Ferrara ◽  
Roberto Felicetti ◽  
Giandomenico Toniolo ◽  
Carla Zenti

2021 ◽  
Vol 881 ◽  
pp. 149-156
Author(s):  
Mochamad Teguh ◽  
Novi Rahmayanti ◽  
Zakki Rizal

Building material innovations in various interlocking concrete block masonry from local materials to withstand lateral earthquake forces is an exciting issue in masonry wall research. The block hook has an advantage in the interlocking system's invention to withstand loads in the in-plane and out-of-plane orientations commonly required by the masonry walls against earthquake forces. Reviews of the investigation of in-plane and out-of-plane masonry walls have rarely been found in previous studies. In this paper, the results of a series of experimental tests with different interlocking models in resisting the simultaneous in-plane shear and out-of-plane bending actions on concrete blocks are presented. This paper presents a research investigation of various interlocking concrete blocks' mechanical properties with different hook thicknesses. Discussion of the trends mentioned above and their implications towards interlocking concrete block mechanical properties is provided.


2021 ◽  
Vol 2090 (1) ◽  
pp. 012148
Author(s):  
G Frunzio ◽  
L Di Gennaro

Abstract The great interest about out of plane behavior of masonry infill walls has recently increased since it is a key point in the seismic modelling of framed structures. Their contribute to the whole seismic resistance of a framed building cannot be skipped. After a review of the literature on the subject, this paper presents a trilinear constitutive model for the out of plane behavior of masonry infills based on the tensile strength of the constituents. Comparisons with literature model are provided and the identification of the model is based on experimental tests.


1975 ◽  
Vol 97 (1) ◽  
pp. 23-32 ◽  
Author(s):  
L. S. S. Lee

Vibrations of an intermediately supported U-bend tube fall into two independent classes as an incomplete ring of single span does, namely, the in-plane vibration and the coupled twist-bending out-of-plane vibration. Natural frequencies may be expressed in terms of a coefficient p which depends on the stiffness ratio k, the ratio of lengths of spans, and the supporting conditions. The effect of the torsional flexibility of a curved bar acts to release the bending stiffness of a straight beam and hence decrease the natural frequency. Some conclusions for an incomplete ring of single span may not be equally well applicable to the U-tube case due to the effects of intermediate supports and the presence of the supporting straight segments. Results of the analytical predictions and the experimental tests of an intermediately supported U-tube are in good agreement.


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