Research On Damage Identification Of Masonry Structure Based On Dynamic Test

Non-destructive testing was first applied to fault diagnosis and aerospace industry of large-scale mechanical equipment.In recent years,with the China's construction industry rapidiy develop,non-invasive testing has gradually entered the construction industry.Commonly used non-destructive testing has impact echo method and ultrasonic method.Infrared imaging static method.The dynamic damage detection technology is not carried out in the civil engineering structure.It is mainly because the industrial and civil buildings are mainly evaluated by the reliability of the structure at the present stage.The work of the civil engineering building is tolerated to a certain extent.In the second half of the 20 th century,structural dynamic damage gradually developed into a new discipline through the intersection of various disciplines.However,how to make the test simple and accurate,it has always been a hot topic for scholars at home and abroad.In this paper,the frequency response function block analysis method is introduced into the masonry structure damage detection.The dynamic signal test analysis system is used to collect the natural frequency,damping ratio and frequency response function of the masonry structure before and after the damage.Through the test of the natural frequency of the masonry structure before and after the test and the analysis of the modal parameters of the frequency response function,the damage location and damage degree of the masonry structure are determined.Comparing the actual damage state of the masonry structure before and after the test,the validity of the curvature ratio of the block-wise frequency response function in the damage identification of civil engineering structures is verified.The analysis proves that the curvature ratio modal analysis method of the block frequency response function can judge the position of the actual damage of the structure.The quadrilateral module can judge the position of the structural damage.Through the analysis of the triangle module,the position of the structural damage can be more accurately located.In the qualitative analysis of the damage degree,a damage calculation formula based on the natural frequency of the structure is proposed.The quasi-static failure test of existing masonry buildings is carried out.The damage factor interval is defined by the failure load-displacement curve.The damage factor is determined by the energy method,and the damage degree of the structure is determined by the measured natural frequency of the structure.Based on this method,the damage degree of two different concrete and brick masonry structures is analyzed,and the damage factor intervals of different materials and structures are analyzed.The results show that the damage intervals of different materials,different structures and different reinforcement methods are also different.