Numerical Simulation To Seismic Damage Of Glass Envelope In Steel Structure Building

Since the 1994 Northridge Earthquake and the 1995 Hyogo-ken Nambu earthquake,the damage of glass curtain wall has drawn the attention of engineering seismic design researchers.However,in the 2008 Wenchuan earthquake in China,the damage of glass envelope structure was rarely found.That made an impression on researchers from Chinese earthquake-resistant industry that the seismic design of China's glass envelope structure is quite safe and reliable.After a lapse of 10 years,in the magnitude 7.0 earthquake of Jiuzhaigou on August 8,2007,it was found that the glass curtain wall and the glass roof were seriously damaged and caused much loss of life and property.Therefore,it is very necessary to re-examine the safety of glass envelopes,which are important features of structures in modern cities.This paper starts with the basic unit of glass envelope structure,and studies its failure mechanism under earthquake action and its nonlinear numerical simulation method,which has important theoretical significance and engineering application value.The main research contents include the following three aspects:1.Literature review and analysis of mechanical characteristics of basic elements of the glass envelope structure.Based on the systematic review of the point-supported glass curtain wall,which is most commonly used in steel structures,the mechanical properties of the basic components of the glass curtain wall were studied respectively.The in-plane stress distribution of the glass panel was obtained by nonlinear buckling analysis.Through the theoretical derivation,the amount of the drift of structures due to the clearance between bolts and spider arms is formulated.2.Taking a steel structure of a hotel in the Jiuzhaigou earthquake as an example,the seismic damage characteristics of the glass envelope structure were systematically analyzed and summarized.The statistics of damage of the glass roof and curtain wall has been compiled and the characteristic has been analyzed.It is pointed out that the damage law of the glass envelope structure of the structure case shows a certain Symmetry and structural inevitability3.A fast nonlinear finite element numerical simulation analysis method for the integrated analysis of the glass envelope structure and the main structure is given.The analysis reasonably explains the seismic damage mechanism of case steel structure building glass envelope structure,which is verified by actual earthquake damage.Taking the steel structure of a hotel with severe damage to the Jiuzhaigou earthquake as an example,the finite element numerical analysis model was established by using SAP2000 software.Starting from the analysis of the actual seismic record characteristics,a finite element numerical analysis model is established.By the analysis,the seismic damage mechanism of lighting roof and curtain wall is obtained.The analysis results indicate that the direct cause of the roof structure damage is excessive absolute acceleration of the glass panel.The direct cause of the destruction of the point-supported glass curtain wall is that the interlayer displacement is too large,causing the extrusion shear deformation of the glass panel.Another reason for glass damage is the support structure was destroyed,the glass attached to which were all destroyed either.At the same time,the damping of the steel structure is very small and many frequencies of the structure are close to the excellent frequency of the ground seismic motion,so that the local vibration of the structure was dramatic.The occurrence of resonance-like phenomena has become an important cause of the destruction of glass envelope.