Structural Analysis And Application Research For Digester

Digester is the essential construction in sewage treatment plant. It is a kind of special structure with high built, big weight, complex structure and stress status. The goal of the dissertation lies in instructing the practice through thorough analysis and research for digester.This dissertation takes the actual project as the background, in which an overall mathematical model, including the superstructure, the pile foundation and the soil, has been established, the static and dynamic analysis for clylindrical digester and oval digester has been carried on, by using existing large-scale finite element analysis software– ANSYS. The static and dynamic parameter which actually matches with the project has been given; the pile earth - structure interaction has been considered into the analysis; the reliable analysis result has been obtained by conducting thorough research theoretically,. Main innovation work and achievement has been gained in the dissertation which including following several aspects:1,This dissertation takes the actual project as the background, in which the static and dynamic analysis by using existing large-scale finite element analysis software has been carried on, the reliable analysis result has been obtained, some proposals for the reality engineering design has been put forward, thus the reliable computation and analysis basis for the digestion tank design has been provided.2,In this dissertation, when the pre-stressed bar is being arranged, the load produced by each bunch of pre-stressed bar was put on where the bunch of pre-stressed bar touch upon, by using the equivalent load law, then the load was inflicted to the wall of the digester, the equivalent load formula was inferred, thus the reasonable control stress in the wall was obtained.3,When we establish computation model of the oval digester, it is the first time that we try to simulate thickness of the digester wall that evenly changed as the height as a conic in order to enhance the model precision effectively. When we establish an interaction model of the oval digester, we divide the entire lower part region into three parts: the pile soil area, soil area nearby and soil area far away among the ground infinite territory. The pile-soil area is simulated to orthogonal anisotropic body equivalent unit; the viscous-elastic artificial boundary simulated with the axial spring-damper unit. Tt is the first time that the interaction theory is applied for analysis of oval digester.4,The method, three-dimension finite element model being established, has manifested the translation and the reverse coupling response. It is the first time that the branch modality - two step analytic method has been applied in the practical research for the pile and soil-digester interaction analysis: no transforming from the structure rude division to the structure detailed division, but directly simulating actual structure to establish simplification model, and can satisfy the precision needed by actual project. This analysis method for oval digester is applied for the first time in related domestic field. .5,In this dissertation, the order class has been also provided for digester static and dynamic analysis by using ANASYS,which can be refer to designer. The method for the pile and soil -digester interaction system dynamic analysis, applied in the dissertation, also has certain reference value to other construction structure earthquake resistance analysis.