| The glass curtain wall is widely used in modern buildings because of its lightweight,transparency,energy-saving,beautiful and novel features.It is an indispensable part of many landmark buildings.The design service life of glass curtain walls is 25 years,and the quality guarantee period of structural adhesive for concealed frame glass curtain walls is 10 years.The glass curtain wall built in early China has approached or even exceeded its design service life,and exceeded the quality guarantee period of structural adhesive.With the increase of the service time of the early concealed frame glass curtain wall,there are more and more problems that the glass panel of the curtain wall falls off due to the aging failure of structural adhesive,which seriously affects people’s lives and property safety.Therefore,the identification,monitoring,and early warning of structural adhesive damage to concealed frame glass curtain walls can effectively prevent the occurrence of glass curtain wall accidents.This thesis conducts experimental research on structural adhesive damage of hidden frame glass curtain wall,and by analyzing and processing the obtained modal parameters,finds out the identification method that can quickly and accurately determine the safety state of structural adhesive,and provides the theoretical basis for the establishment of structural adhesive damage detection/monitoring system of hidden frame glass curtain wall,the main research contents of this thesis are as follows.（1）A complete structural adhesive damage test program was designed for the structural adhesive debonding damage of hidden frame glass curtain wall,and four groups of 12 experimental conditions with different degrees of damage and different damage locations were designed according to the possible damage of structural adhesive in the actual curtain wall.The experimental modal analysis of the 12 conditions found that the first-order modal vibration pattern is more representative for identifying the structural adhesive damage,but the damage cannot be accurately identified only by the vibration pattern or frequency diagram.（2）In response to the problem that the inherent frequency and vibration pattern obtained directly from the experiment are not sensitive enough to identify the structural adhesive damage,the concept of rate of change is introduced,and it is found that the rate of change of inherent frequency can more accurately determine the degree of structural adhesive damage,but cannot identify the damage location;the rate of change of first-order modal displacement can better identify the location of structural adhesive damage,but cannot accurately identify the degree of damage.（3）Based on the experimental modal parameters,the curvature mode of the glass panel was obtained,and the changes in the curvature mode of the glass panel were analyzed when the structural adhesive was damaged in different states,and the curvature mode difference and the curvature mode change rate were obtained from them.It is also easier to identify the damage when the damage is small.（4）Comprehensive analysis based on intrinsic frequency rate of change,modal displacement rate of change,curvature modal rate of change and curvature modal difference and other indicators for comparative analysis found that the damage recognition method based on the rate of change has more advantages in the recognition of damage,the damage recognition method based on the intrinsic frequency rate of change is more suitable to identify the degree of damage of structural rubber,the damage recognition method based on the modal displacement rate of change is more sensitive in the recognition of damage location,and the damage recognition method based on the curvature modal rate of change is more sensitive in the recognition of damage location.The damage recognition method based on the modal rate of change of curvature is more sensitive in the identification of damage location,while the damage recognition method based on the modal rate of change of curvature can better identify the damage location and damage degree at the same time,which is more suitable for damage detection and has better application prospects. |
