The Seismic Behavior Of Chimney After Considering The Chimney Intake

Chimney is the most common type of structures in daily life, its seismic safety performance is related to a nearby building and has very big effect to the whole city of seismic mitigation lifeline function. Over the years, there are many analysis about the seismic performance of chimney and many valuable ideas. In the past there was assumption that the hole is not open in the tube wall in the process of finite element analysis. In this case, simplified the process of modeling, shorten the time of calculation, but the result is different form the actual situation. Therefore, it is necessary to make the further discussion of earthquake resistance performance of the chimney after considering chimney intake.In this paper, using finite element program to study dynamic response characteristics to the chimney, getting the differences about dynamic characteristics of the chimney,which provided some reference for seismic design of the structure of chimney.In this paper, the author carries out the static analysis,the modal analysis,the spectrum analysis and the elastic analysis under earthquake effect to the finite element model in order to study the static and dynamic response properties of chimney subjected to seismic action. The results of the analysis shows that the structural vibration,vertex displacement,the distribution and the emergence of time of the maximum stress had changed a lot after considering the hole in the tube wall. Stress near the hole changed complicated.To further understand the failure mechanism of the chimney after considering chimney intake under earthquake, the author carries out elasto-plastic analysis to chimney which is different form the position of the hole, the height and the quantity, under the 3d seismic action and the vertical seismic action alone. The result indicates that whether under 3d seismic or under vertical earthquake alone, the stress value and the change of stress along the height of the tube wall is quite different to the chimney after considering the chimney intake.So the effects of the hole to the chimney should not be ignored when the earthquake response analysis is done.