The Analysis Method Of Wind-induced Fatigue Of High-rise Reinforced Concrete Structure In The Life Cycle

With the continuous progress of science and technology,more and more high-rise building structures are appearing.And with the increase of the height of the building structure,the wind-induced fatigue of the structure in the life cycle has become a problem that can't be ignored.And the main contents of this paper are as follows:In this paper,we deduce the time-varying model of reinforced concrete structure at the material level.Based on the existing residual strength model of concrete materials and considering the characteristics of wind-induced fatigue analysis,the fatigue model of concrete structure under wind-induced fatigue is derived by using the envelope of residual strength of concrete structure and concrete residual strain.According to the fatigue damage model of steel bars determined in fracture mechanics,we can derive the fatigue model of steel bars under wind-induced fatigue combined with the fatigue damage theory.According to wind speed data over the years of Dali,Yunnan,select the WSW direction of Dali,Yunnan Province as the wind direction,then we can determine the shape parameters of Weibull distribution in the direction,and then use Weibull distribution to describe the probability distribution of wind speed in the whole year.Under the wind-induced fatigue in life cycle,the fatigue damage eventually leads to the continuous reduction of the actual residual strength of the structure,which means in the finite element analysis,the constitutive relationship of materials is constantly changing.In OpenSees,it is more convenient to modify the constitutive relationship of materials,which can more effectively analyze the performance degradation of structures under wind-induced fatigue in the life cycle.According to the theory of fatigue damage,the stress time history which is obtained from the finite element analysis can be analyzed.Combined with the S-N curve and Miner linear criterion,we can finally get the fatigue damage of materials.On the basis of fatigue damage,combined with the fatigue time-varying model of steel bar and concrete,we can analyse the performance degradation of the structure in the 50 years service life.Through the analysis,it can be seen that under the wind-induced fatigue action,the damage of steel bars is larger and the steel bar is more sensitive to the wind-induced fatigue,while the damage of concrete materials under the wind-induced fatigue action is much smaller.