Effects Of Composition And Amplitude-frequency Characteristics Of Ground Motion Acceleration On Structural Response And Failure

The selection of ground motion is one of the main contents of Structural seismic.The uncertainty of ground motion is an important part of the uncertainty of Structural seismic performance design.It is of great significance for engineering design to know the influence of seismic wave components and different combinations on structural response and its leading factors.Therefore,it is very important for seismic design to sort out the main factors that control the failure process and response characteristics of the structure.Based on this,key factors of the ground motion that play a key role in the structural failure and the elastic-plastic displacement from the components of the ground motion will be studied,also its influence on the structural failure evolution characteristics and the structural elastic-plastic displacement response.A numerical analysis model is established to analyze the structural failure induced by ground motion,and the response characteristics and failure process of the structure under the action of ground motion are calculated.Based on the calculation of three typical seismic actions of El Centro NS 1940,Taft and whitter,the different failure processes caused by different seismic actions are analyzed.Based on the decomposition and recombining of seismic components and the numerical calculation of the structural failure process,it is shown that the influence of the simple harmonic components and different synthesis methods of seismic on the structural failure process.The results show that the failure characteristics of the structure are mainly reflected in the location,number and plastic development degree of the plastic hinge.The simple harmonic component of frequency before the natural frequency will make the structure completely invalid.Under the action of high frequency simple harmonic component,the structural component has not entered the plastic development.The results show that the simple harmonic component with larger amplitude plays a leading role in the development of structural plastic hinge,while other components play a leading role in the development sequence of structural plastic hinge.The existing harmonic components are close to the distribution and development order of plastic hinges under EL Centro ground motion,but they have noobvious effect on the number and development degree of plastic hinges.The influence of the simple harmonic components of the ground motion and different synthetic results on the structural elastic and elastoplastic displacement responses is compared and analyzed.The results show that for the simple harmonic component,the elastic displacement of the structure is mainly affected by the frequency.The position of the weak elastic floor under the action of the simple harmonic component is the same as that of the weak elastic floor.For the composite component,its amplitude is the key factor affecting the elastic displacement response of the structure.The harmonic component with larger amplitude plays a dominant role in the distribution of structural elastic and elastoplastic layer displacements and interlayer displacements in the composite component.The harmonic component with the largest amplitude affects the magnitude of the elastoplastic maximum and interlayer displacements of the ground motion and the position of the weak floors,but the moment of occurrence of the maximum elastoplastic interlayer displacement under the ground motion has no obvious relationship with the characteristics of the components of the harmonic component.