Research On Structural Displacement And Analysis Under Earthquake

According to the previous earthquake data,many structures did not collapse directly or cause visible distortion after the main earthquake,but there was already a certain degree of damage.Since these damages could not be quickly and effectively detected and their structural performance evaluation was carried out in time,which affected the earthquake relief work,the damaged structures were more likely to cause more serious damage in the aftershocks.Due to many uncertain problems after the earthquake,the traditional contact measurement method is severely limited after the earthquake.Therefore,this paper uses the vision-based non-contact measurement method to measure the structural displacement under earthquake.Furthermore,for the reinforced concrete frame structure,the maximum displacement in the earthquake is reversed by the residual displacement of the structure,and the structure is quickly evaluated using the above two ratios.The main research contents are as follows:?1?Reviewing the research and practice of vision-based measurement methods in and out of the laboratory,summarizing their measurement targets,equipment used,methods and deficiencies,etc.;reviewing the maximum displacement and residual displacement.The study of the relationship between the two ratios,summed up the research methods of the predecessors,the form of the calculation model and the choice of ground motion records.?2?Design and carry out a large shaking table test of the reinforced concrete-filled wall structure model,write a vision-based displacement measurement program through MATLAB,and measure the displacement of each floor of the structural model using a single camera.Use shape-based tracking methods to compare different filtering and image processing functions to eliminate the effects of noise,low light intensity,and uneven illumination on the measurement results during the test.?3?Compare the floor displacement and acceleration time history curves obtained by traditional measured and vision-based measurement methods.The displacement response data of the structural model under white noise is measured.The eigensystem implementation algorithm is used to identify the modal parameters of the structural model,and the modal frequency and modal damping ratio of the structure under various working conditions are obtained.?4?According to the current building structure design code,a six-story three-span reinforced concrete frame structure is designed using PKPM.Based on the OpenSees finite element analysis software,using S_a?T₁?as the ground motion intensity factor,the structure was modeled using 65 real ground motion records and nonlinear dynamic analysis was performed to extract the IDR_max and RIDR under different working conditions,and perform a line fitting.