scholarly journals COMPREHENSIVE NONLINEAR ANALYSIS OF FAILURES OF FIRE-SPRINKLER SYSTEM BASED ON FINITE ELEMENT MODELLING AND AMBIENT VIBRATION TESTS

2021 ◽  
Author(s):  
Shakhzod Takhirov ◽  
Amir Gilani
2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Sergio Vincenzo Calcina ◽  
Laura Eltrudis ◽  
Luca Piroddi ◽  
Gaetano Ranieri

This paper deals with the ambient vibration tests performed in an arch dam in two different working conditions in order to assess the effect produced by two different reservoir water levels on the structural vibration properties. The study consists of an experimental part and a numerical part. The experimental tests were carried out in two different periods of the year, at the beginning of autumn (October 2012) and at the end of winter (March 2013), respectively. The measurements were performed using a fast technique based on asynchronous records of microtremor time-series. In-contact single-station measurements were done by means of one single high resolution triaxial tromometer and two low-frequency seismometers, placed in different points of the structure. The Standard Spectral Ratio method has been used to evaluate the natural frequencies of vibration of the structure. A 3D finite element model of the arch dam-reservoir-foundation system has been developed to verify analytically determined vibration properties, such as natural frequencies and mode shapes, and their changes linked to water level with the experimental results.


2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Halil Nohutcu

Historical structures are the values that are of great importance to that country, showing the roots of a country, and must be passed on from generation to generation. This study attempts to make a contribution to this goal. Seismic damage pattern estimation in a historical brick masonry minaret under different ground motion levels is investigated by using updated finite element models based on ambient vibration data in this study. Imaret Mosque which was built in 1481 AD is selected for an application. Surveying measurement and material tests were conducted to obtain a 3D solid model and mechanical properties of the components of the minaret. Firstly, the initial 3D finite element model of the minaret was analyzed and numerical dynamic characteristics of the minaret were obtained. Then, ambient vibration tests as well as operational modal analysis were implemented in order to obtain the experimental dynamic characteristics of the minaret. The initial finite element model of the minaret was updated by using the experimental dynamic results. Lastly, linear and nonlinear time-history analyses of the updated finite element model of the minaret were carried out using the acceleration records of two different level earthquakes that occurred in Turkey, in Afyon-Dinar (1995) and Çay-Sultandağı (2002). A concrete damage plasticity model is considered in the nonlinear analyses. The conducted analyses indicate that the compressive and tension stress results of the linear analyses are not as realistic as the nonlinear analysis results. According to the nonlinear analysis, the Çay-Sultandağı earthquake would inflict limited damage on the minaret, whereas the Dinar earthquake would damage some parts of the elements in the transition segment of the minaret.


2012 ◽  
Vol 166-169 ◽  
pp. 935-938
Author(s):  
Ming Rong Zhou

Finite Element modelling (FEM) has been expounded with the introduction of concrete materials constitutive relationship model.Meanwhile, bearing capacity of simply supported concrete beam is simulated by adopting FEM software-ANSYS through the whole computation process. Moreover, results of computed values and experimental values are compared demonstrating that related nonlinear analysis and treatment can be done well in this approach.


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