Phenomenological invariant-based finite-element model for geometrically nonlinear analysis of thin shells

2007 ◽  
Vol 196 (49-52) ◽  
pp. 4952-4964 ◽  
Author(s):  
V.V. Kuznetsov ◽  
S.V. Levyakov
2007 ◽  
Vol 340-341 ◽  
pp. 335-340 ◽  
Author(s):  
G.J. Nie ◽  
Zheng Zhong

A new elasto-plastic and geometrically nonlinear finite element model of space beam considering restraint torsion and the coupling effect of deformations is presented in this paper. The warping restraint torsion and the coupling effect of deformation are considered in the displacement formulation of arbitrary point on the space beam. The geometrical relationship of arbitrary point is derived according to the definition of Green strain. The elasto-plastic and geometrically nonlinear finite element model of space beam is derived using Updated Lagrange description. The effect of axial force, shearing force, biaxial bending moment, moment of torsion and bimoment is involved in the geometrical stiffness matrix of element. The yielding developments both across the section and along the axis of the member are taken into consideration by selecting Gauss points. The full historical nonlinear analysis is achieved using the method of load increment and modified Newton-Raphson method. The validity of the new model derived in this paper is proved by numerical example. This new model can be used in the elasto-plastic and geometrically nonlinear analysis of space beam structures constructed by the members of arbitrary cross section.


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.


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