Research On Damage Identification Method Of Component Glass Curtain Wall Supporting Structure

The building curtain wall is the product of the development of modern science and technology,and it is a distinctive feature of modern high-rise buildings.After more than 30 years of development,China has become the world’s largest curtain wall producer and user country.As more and more curtain walls are put into use,various safety issues such as plate falling,glass self-explosion,and corrosion and fracture of structural parts have also followed.Therefore,it is particularly important to identify damage and monitor the health status of the curtain wall.Aiming at the structural damage problem of the component glass curtain wall support structure,this thesis uses a method of combining simulation and experiment,taking adapters and bolts as the research object,and studies the impact of the structural damage of the glass curtain wall supporting structure on the dynamic characteristics of the supporting structure.This thesis explores the criteria for judging structural damage of glass curtain wall supporting structures,and lays a theoretical foundation for the establishment of a structural damage identification and monitoring system for glass curtain wall supporting structures.The main research contents are as follows:(1)The damage of structural parts was studied experimentally.The dynamic data acquisition instrument(DH5992)was used to analyze the changes in the modal parameters of the structure when the bolts are loosened and the damage degree of the adapters is different.The experiment found that when the bolts are loose,each order of the structure is inherent The frequency decreases with the increase of bolt damage.The second,third,and fifth-order natural frequencies of the structure change the most;when the adapter is damaged,the natural frequencies of the structure change with the increase of the damage degree.The third-order natural frequency changes the most.Therefore,through the natural frequency change of the structure,the damage degree of bolts and adapters in the component glass curtain wall support structure can be identified and monitored.(2)Regarding the identification of the damage degree and damage position of the adapter in the component glass curtain wall support structure,through modal analysis,the influence law of the different damage degree and damage position of the adapter on the modal parameters is studied,and it is found that when the adapter is damaged,the natural frequencies of the structure gradually decrease with the increase of the damage of the adapter,and as the damage of the adapter increases,the second,third,and fifth-order natural frequencies of the structure decrease significantly Therefore,the natural frequency has the ability to identify the degree of damage;when the adapter is damaged,the third and sixth modes of the structure change significantly;when the adapter is damaged at different positions,the sixth mode of the structure changes significantly,according to The change of the mode shape can realize the identification of the degree of damage to the adapter and the location of the damage.(3)For the identification of the damage degree and position of the bolts in the component glass curtain wall support structure,the finite element numerical simulation method was used to conduct a modal analysis of the bolt loosening under different working conditions,and it was found that as the bolt pre-tightening force decreases,That is,the bolt damage is gradually serious,the overall rigidity of the structure is reduced,and the natural frequency is also reduced.When damage occurs,the second,third,and fifth-order natural frequencies of the structure have a greater degree of influence,so the natural frequency can be used as bolt loosening Basis for degree identification;when bolts in different positions are damaged,the mode shape and displacement mode of the structure change,and the first-order mode and fifth-order displacement mode of the structure change significantly,so the first-order mode and fifth-order mode of the structure The displacement mode can be used as a basis for judging the location of bolt damage.