Granary Stress Steering Ratio And Stability Behavior Research

Silo Effect of granular matter is an important reseach direction of statics about granular matter. One hundred years ago, a model of continuous medium was put forward by a german Janssen, which was used for describing static stress changes of Silo and universally acknowledged, but some hypothesis was not tested by definite experiments. By reading document in last decade, we saw the major snag. The ratio of horizontal to vertical stress in field of engineering is 0.5. The ratio is also the ratio of Janssen which is given by a Empiric Formula. Experts in field of particles find that the ratio of J used in field of engineering is not right. Focus on the difference, the paper started theory of computation and experiments on the problem. The major sdudy points are as follows:Firstly, in terms of complex system of particles, There is an affinity between the inner static stress field and tangential frictional force between particles along the borderline and the wall of Silo. The paper measure maximal friction coefficient on interface between particles and three different object on purpose to clarify this boundary conditions. The results indicated that friction coefficient between particles and interface of object can not be simply substituted by friction coefficient among material or friction coefficient between one particle and interface of object. These experiments measured the friction coefficient applied to the measurements reported in the literature, and the laboratory silos in the text, we will find that the value of J is greater than 0.5 in some cases, so we can come to conclusion that there is static field which act contrary to Jack Empiric Formula.In order to research and clarify phenomenon which act contrary to Jack Empiric Formula, the paper get ordinary solution of nonlinear spring in planar Stress-strain area. The results indicated that ordinary solution can really give stresses having the observed big Janssen ratio. On the basis of this thoery, the Janssen ratio is allowed to vary in certain range, which do not always supply Jack Formula. This means that the elastic theory to describe the history and preparation, including the large value of J of the complex static phenomenon about granular matter, but the need to carefully deal with the plastic particulate matter on the boundary conditions. Besides when the value of J is absolutely greater then 0.5, stress field got from elastic theory drifts off assumption of Jassen model. This phenomena will need to be further gone into.