Finite Element Analysis Of Locally Frayed Reinforced Concrete Silo

Since the20th century, reinforced concrete silos were quickly developed and widely used in a lot of fields, such as light industry, metallurgy, electric power, coal, building materials, food and so on. At the same time, domestic and foreign scholars made a large number of studies about silo structures, which can be attributed to the following two main directions:one is the horizontal lateral pressure acted by stored bulk solid on silo walls; the other is research about seismic performance of silo structures.In the last ten years, along with the development of national economy, China’s cement industry boomed quickly, more and more large cement mill were built one by one, cement production was greatly enhanced, at the same time, the local fray of reinforced concrete silo wall was becoming increasingly revealed. The fray mainly occurs in small-diameter clinker bin and small-diameter limestone bin, in addition, eccentric discharge in process design, impact and friction the coarse aggregate act on the wall of the bin also bring different degrees of fray in large-diameter bin. This paper bases on an actual project, uses the general finite element analysis software ANSYS, researching the influence of local fray in the silo wall on the safety and seismic performance of reinforced concrete silo structures.A lot of domestic and abroad literatures about the silo structures were read to analyze the research status and the existing shortcomings. Based on some assumptions and former theoretics, the local fray in the silo wall is considered in this paper, and its influence on safety and seismic performance of silo structures is also studied here.In the research about local fray in the silo wall’s influence on safety of silo structures, loads considered in conventional design of the reinforced concrete silo structures are taken into account here, including the structure gravity, the stored bulk solid’s horizontal lateral pressure and vertical frictional force on silo walls, wind load and horizontal earthquake action, according to the most unfavorable load combination, research the influence of local fray in silo walls on the internal force of silo walls, summarize the changing rule of silo wall’s internal force along with the expand of frayed area. And estimate the biggest frayed area according to the changing rule, evaluate the influence of local fray in the silo wall on the safety of silo structures.In the research about local fray in the silo wall’s influence on seismic performance of silo structures, the original model(unfrayed model) and the frayed model are both built, modal analysis and spectrum analysis are both carried out, the following two load cases-full filled and unfilled are both considered. Modal analysis is used to study local fray’s influence on reinforced concrete silo structure’s dynamic characteristics, including the natural vibration frequency, cycle and vibration model; Spectrum analysis is used to compare both the original model and the frayed model’s response under the earthquake intensity of7degrees, including horizontal displacement, shear stress, vertical stress, the equivalent stress and total bottom shearing force. Compare the maximum of these response between the original model and the frayed model, and summarize the change rule of the maximum of these response, evaluate the local fray in silo wall’s influence on seismic performance of reinforced concrete silo structure.