Study On Wind-induced Vulnerability Of High-rise Reinforced Concrete Chimney

A considerable number of high-rise reinforced concrete chimneys were designed and built at the end of the 20 th century and the beginning of the 21 st century.Up to now,the traditional concrete chimneys generally have problems such as cracks,aging and poor durability.Chimney is a tall structure with large slenderness ratio.In extreme weather,the chimney will suffer from continuous and strong repeated wind load,causing undetectable potential damage to the chimney,and even failure and collapse in serious cases,which will have a great impact on industrial production.The investigation shows that the frequent occurrence of various disasters is the first cause of economic losses at home and abroad.Although domestic scholars have conducted some research on vulnerability,they are concentrated on steel structures such as powerhouse and transmission tower,and the research on high-rise concrete structure is rarely involved.Therefore,this topic is of great significance to carry out the research on wind-induced vulnerability of high-rise reinforced concrete chimney.For this purpose,ABAQUS will be used to analyze the wind-induced vulnerability of the desulfurization chimney of a power plant,and the following aspects are specifically studied:1、The principle of simulating wind speed is written into code by MATLAB,and the time history of fluctuating wind speed at different points based on Davenport spectrum is obtained;The damage mechanics model of concrete under wind load is used to describe the damage characteristics of concrete.2、The refined finite element model is established by ABAQUS,and the frequencies of each order of the structure are obtained through modal analysis;Considering the uncertainty of materials,the analysis samples of structures are obtained by Latin hypercube sampling;The nonlinear dynamic time history analysis is carried out for each sample,and the top displacement time history curves of different samples are obtained.3、Define the failure state and performance point of the structure.Through pushover analysis,the base shear displacement curve of the structure is obtained,and the performance points of the structure under different failure states are obtained through the curve;The 0°and 90° displacements were analyzed by regression.4、According to the vulnerability theory,the wind-induced vulnerability curve of chimney based on Davenport spectrum is obtained;Based on the system vulnerability theory,combined with the vulnerability curves of two independent directions,the vulnerability curve of chimney system is obtained;The vulnerability curves based on Kaimal spectrum and Karman spectrum are further obtained to study the influence of different wind spectra on the wind resistance of chimney.