Abstract: Based on the assumptions of Janssen formula, the powder static pressure distribution is discussed and the analytical formulas are established. The relevant numerical study is fulfilled through finite element contact analysis. Through comparing the finite element analysis results with the analytical results, it shows that the analytical formulas have error. The reason is mainly that the special contact state formed by the special silo structure is not incarnated in the analytical formulas. Based on the finite element analysis result, the analytical results are amended to give the final formulas of contact pressure on the pyramidal silo. The formulas show that the contact pressure correlates with the attribute parameters such as silo material, loose material bulk density and internal friction angle, as well as the design parameters such as silo wall obliquity and silo height. The final formulas are programmed to implement pressure load by using ANSYS parametric design language. The load distribution graphs are consistent with the scatter diagram, and the loading languages have good generality and portability. The formulas can simplify relevant calculation, and may be regarded as a supplement of Janssen formula.

Key words: Contact, Finite element, Powder static pressure, Pyramidal silo