Design Research Of Steel Silos And Numerical Simulation Of Bulk Material Pressure

The steel silo is widely used for the storage and transport of various bulk materials. Due to the complicated shell behaviour, this structure is liable to be damaged. While in our country, the research of the steel silo is terribly lacked, and the corresponding code cannot satisfy the practical application. In view of this case, the system research on the load, strength and visual programming of the circular steel silo had been carried out in this thesis. Also, the research on the application of numerical simulation to the bulk material pressure was conducted.The silo is usually composed by three parts: silo wall, hopper and transition junction. The article summarised the calculational methods of normal pressure, tangent friction force and membrane stresses acting on the silo wall and the hopper shells under the filling or discharging. The computation of circumferential compressive force and stresses of intersection, the relevant compressive areas were introduced too. The differences between our national code and European code were compared.Under the axial compression and geometric imperfection, the silo wall is easy to buckle. The huge meridional membrane stress at the top of the hopper can easily lead to the rupture and plastic mechanism collapse of the hopper at the critical joints. In the transition under the tremendous compressive force, the plastic failure and buckling is easy to happen. According to all of these ultimate failure states, a system summary about the computations of the strength and stability of the three parts were made in this article.In order to avoid the complex computational process, the article compiled a steel silo analytic programme with visual programming language VB6.0. The programme has six modules, including parameter input, load analysis, strength analysis, finite element interface, practical application and help file. The load computing and strength capacity of the silo wall, hopper and transition joints are fullfilled by the programme, which could supply the ANSYS APDL files for three kinds silo: conical-bottom silo, flat-bottom silo and colomn supported silo. The linear elastic analysis, the eigenvalue buckling analysis and the nonlinear buckling analysis considering the circumferential welding depressions are facilitated by this programme.The bulk material pressure is the foundation to determine the loads and stresses of silo. The finite element analysis on the static pressure of the conical bottom silo and flat bottom silo were carried out by using Drucker-Prager model and face to face contact element, on the basis of a review of the numerical simulation research progress of the bulk pressure. Then the parameter analysis was presented considering the Poisson ration, friction coefficient, internal friction angle and dilatancy angle.