Study On The Static And Dynamic Mechanical Behavior Of Grain Steel Silo With Stiffeners

More than half of the silos have been constructed as steel silos. Steel silos have the advantages oflight self-weight, short construction period, convenience of automated manufacturing. Generally,the structure of steel silo is thin-wall cylindrical structure, which has the characteristics of highcapacity, small occupation area, easy to mold and so on, These defects have led the structures toscrap during their service life. In order to solve these problems, people usually improve theload-bearing capacity and the stability of the structure by using the method of fixing stiffenersinto the silo. Meanwhile, for the convenience to clean the residue of stored material in the siloafter unloading finished, there are two symmetrical precast clean-up vents in the bottom of thesilo. The clean-up vent is an initial defect for the original integrated cylindrical shell of the silo,which will weaken the load-bearing capacity of the structure.A grain steel silo of a port is studied in this paper, considering of the effect of stiffeners, itestablishes two models with rectangular bottom clean-up vent and round bottom clean-up ventseparately, by stressing mechanic load，temperature load，and combination of mechanic andtemperature load separately on the two models，through analyzing the stress, strain anddisplacement of the two models under condition of such three loads，conclude the average stressof the silo with rectangular bottom clean-up vent is48%greater than that of the silo with roundbottom clean-up vent in the same load condition. In addition, the calculation results indicate thatthe stress level around the round vent can satisfy the technical requirement. However, when theoriginal round vent has been molded into the rectangular vent, the Mises stress level in manyregions around the rectangular vent is beyond yield strength of steel, which will result in largedeformation around the rectangular vent; the temperature load’s impact on steel silo can not beignored either, comparing single mechanic load with combination of mechanic and temperatureload, it is found that the temperature load has a great effect to the structure of steel silo as well, itmay lead the maxisum stress of the silo increace18%. Therefore, steel silos should be designedin consideration of temperature factor; Taking into account the dynamic overpressure caused byunloading, proportional increased values of lateral pressure and friction force are separately calculated in the thesis, through the comparison: it is found that the effect of dynamic frictionforce is the main reason increasing the stress of steel silo, yet the effect of dynamic lateralpressure isn’t the direct reason increasing the stress of steel silo.