scholarly journals NON-LINEAR KINEMATIC ANALYSIS OF MASONRY WALLS OUT-OF-PLANE LOADED. THE COMPARATIVE ROLE OF FRICTION BETWEEN INTERLOCKED WALLS

Author(s):  
Claudia Casapulla ◽  
Luca Umberto Argiento
2019 ◽  
Vol 817 ◽  
pp. 325-333
Author(s):  
Simonetta Baraccani ◽  
Giorgio Dan ◽  
Angelo Di Tommaso ◽  
Tomaso Trombetti

The analyses of the structural damages detected on the Italian churches after the recent earthquakes (Emilia 2012, Umbria-Marche 2016) highlighted the high vulnerability to the overturning of the façades. The façades collapse mechanisms are strongly dependent on the connection details between orthogonal masonry walls, the windows, the construction techniques and the possible restraining horizontal elements, such as tie-beams, bi-lateral connected roof, etc. Several studies focus on the evaluation of vulnerability of the church façades using different approaches, from global analyses (FEM and /or Discrete Element Methods) of the entire building, to local analyses (linear and non-linear kinematic approaches). The aims of the present paper is to use the method based on capacity spectra to evaluate the vulnerability of the church facades and the optimization of specific devices as tie-rods to improve their seismic behavior. The non-linear approach is now accepted by several standards regarding the evaluation of risks of collapse mechanisms for masonry walls of the facades. Appropriate devices have been considered in order to calibrate the capacity curve and to optimize the interventions. The out of plane rotation of blocks can be modified with various elasto-perfect-plastic tendons with appropriate retentions (while composite materials could be used to preserve integrity of blocks). The tendons can be allocated in proper location and the length of each calibrated to best determine their stiffness. This procedure have been here applied to the study of the façade of Aula Magna S. Lucia of the Bologna University, considering also the problem of the interaction with the structure of the roof.


2021 ◽  
Author(s):  
Chenjie Yu ◽  
Sander Meijers

Abstract Since 1986, earthquakes have occurred in East Groningen , but most houses, schools and are made of unreinforced masonry, which must now withstand magnitude 4 earthquakes. This has created an urgent need to assess large amounts of buildings in a fast but reliable manner. The out-of-plane behaviour is important for seismic assessments of unreinforced masonry buildings. Although the most accurate analysis method to determine the out-of-plane response of such walls is non-linear time-history analysis ( NLTH ), non-linear kinematic analysis ( NLKA ) provides a simple, fast but still reliable solution due to the computational difficulties of NLTH for structures constructed of unreinforced masonry. In this paper, the out-of-plane behaviours of masonry structures are up-scaled from a component scale to a provincial scale in a multi-scale manner. A map-oriented database is established to describe both local behaviours of walls and global behaviours of a province. The out-of-plane assessment by non-linear kinematic analysis ( NLKA ) is automated via the database without further calculations after the static analysis. The database provides a solid guidance to determine which detailed assessment methods will be adopted with limited data before a FEM model is built


2015 ◽  
Vol 44 (13) ◽  
pp. 2359-2376 ◽  
Author(s):  
Linda Giresini ◽  
Massimo Fragiacomo ◽  
Paulo B. Lourenço

Author(s):  
Gilles Tissot ◽  
Mengqi Zhang ◽  
Francisco C. Lajús ◽  
André V. Cavalieri ◽  
Peter Jordan ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Francesco Gabriele ◽  
Mattia Udina ◽  
Lara Benfatto

AbstractThe hallmark of superconductivity is the rigidity of the quantum-mechanical phase of electrons, responsible for superfluid behavior and Meissner effect. The strength of the phase stiffness is set by the Josephson coupling, which is strongly anisotropic in layered cuprates. So far, THz light pulses have been used to achieve non-linear control of the out-of-plane Josephson plasma mode, whose frequency lies in the THz range. However, the high-energy in-plane plasma mode has been considered insensitive to THz pumping. Here, we show that THz driving of both low-frequency and high-frequency plasma waves is possible via a general two-plasmon excitation mechanism. The anisotropy of the Josephson couplings leads to markedly different thermal effects for the out-of-plane and in-plane response, linking in both cases the emergence of non-linear photonics across Tc to the superfluid stiffness. Our results show that THz light pulses represent a preferential knob to selectively drive phase excitations in unconventional superconductors.


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