Papers by Author: Fang Yuan

Abstract: The test use the practical reduced scale model of flat-bottomed silo to determine the value of static lateral pressure of silo walls, dynamic pressure of discharge process and dynamic pressure of silo walls which comes from eccentric discharge. Then the work is, respectively, to analyses static pressure value and flat-bottomed silo standard value, dynamic pressure value and static pressure value, as well as dynamic silo walls overpressure contrastively, and to calculate the coefficient size of each survey point of silo walls. Thus this trial verifies that the existence of the phenomenon of the silo dynamic overpressure and dynamic overpressure caused by eccentric discharge, also, it illustrates the problem of silo dynamic pressure we cant ignore during the engineering design.

Abstract: The two-dimensional viscoelastic solid is considered in symplectic system. The general solutions of the governing equations include zero eigensolutions and non-zero eigensolutions. Zero eigensolutions can describe all the Saint-Venant problems, and non-zero ones are local effect solutions. Via this analytical approach, the final solution of the problem can be expressed by the linear combination of the general eigensoutions. In this paper, the local effects are described by employing this analytical approach.

Abstract: The scale model of squat silo in large diameter was established with Particle Flow Code (PFC3D) in this paper. This scale model uses the centrifuge model test principle for reference and provides the field of gravity in the calculation of archetypal squat silo. When the silo filled with granules reaches static equilibrium state, record the static lateral pressure measurement values of its each column measured wall, followed by eccentric discharge simulation in different operating conditions, while monitoring the changes of Measured walls in five different directions during discharging granules, in order to analyze the influence of eccentric discharge on the lateral pressure of large diameter squat silos wall. Thus the following conclusion can be obtained: （1）Overpressure coefficient is close extensive between eccentric distance and far extensive between physical reference of storing material.（2）Under the same condition, the overpressure coefficient of same side wall will be minished with the increasing of discharge port.（3）For the same silo model, maximum pressure coefficient is related with eccentric distance, discharge port size and the position with the wall measured, and its value is greater than the calculated value of standard, because the overpressure coefficient calculation formula is only related with silo diameter and eccentric distance, and this is worth further discussion.

Abstract: This paper discusses thermo-viscoelastic problems using the symplectic system method. With the aid of the symplectic character and the Laplace integral transformation, all general solutions of the homogeneous equation are obtained directly via zero eigensolutions and their Jordan forms of the corresponding symplectic dual equations. The special solution of the non-homogeneous equations are given by applying the the adjoint symplectic relation between the eigensolutions. Examples show the results of the direct symplectic method, and reveal the creep and relaxation properties of the time dependent viscoelastic materials.

Abstract: This paper introduces a finite element solution for predicting the normal pressure on large diameter squat silo wall, with the application of contact element and nonlinear model. The finite element analysis (FEA) described in this paper is compared with the full-scale tests and Coulomb theory and the Chinese Code. The predicted results are in good agreement with Coulomb theory, when the top of the stored solid is horizontal; while the result of Coulomb theory is much larger than the other solutions, when the top of the stored solid is a conical surcharge pile. The results from the modified Rankine theory in Chinese Code are acceptable in both conditions. Finally, the effects on the normal pressure of Young′s Modulus are also discussed.