Dynamic Response Analysis Of Grain Bulk Material-steel Silo Structure Under Earthquake Action

Grain is an important strategic material that concerns the international people’s livelihood.China is one of the largest grain producers,consumers,importers and grain reserves in the world.In all kinds of grain storage structures,silos are widely used in all kinds of grain storage warehouses,ports,processing plants and so on as a result of their advantages of environmental protection,land saving and high mechanization.However,the silo is prone to damage or collapse under the earthquake.At present,the interaction mechanism between grain bulk and grain bulk and between grain bulk and silo is not clear.Therefore,it is necessary to study the seismic response of grain bulk and silo structure and the seismic performance differences of different silo structures.The main contents of this paper are as follows:(1)Determination of numerical simulation method for grain bulk-steel silo.Based on the rationality and efficiency of the calculation model,some key problems in the numerical simulation are discussed,including the selection of the constitutive model of the storage,the selection of the damping model of the structure,the contact simulation method between the storage and the structure,and the boundary constraints.By comparing the numerical simulation results with the experimental results,the rationality and reliability of the numerical simulation method are verified.(2)Based on an actual steel silo project,a refined finite element model is established,and appropriate seismic waves are selected for seismic response analysis.The dynamic characteristics,structural acceleration response,structural displacement response,dynamic lateral pressure of storage,overpressure coefficient,structural energy dissipation performance and structural strain response of silo models with different loading heights were analyzed and summarized.The results show that the first and second order modes of the silo full model are translational,and the third order modes are global torsion.The absolute acceleration peak amplification coefficients of full warehouse model are greater than those of empty warehouse model.In most working conditions,the peak value of relative displacement of half warehouse wall is the largest.The dynamic side pressure of the full warehouse is greater than that of the half warehouse;The overpressure effect in the middle of silo wall is significantly greater than that in the full silo under the condition of half silo.The cumulative hysteretic energy dissipation response of the full warehouse model is the largest under the action of artificial waves.When the silo is full,the maximum strain is concentrated in the bottom area of the silo.(3)The numerical analysis models of silo structures with different ratio of height to diameter and different types of silos(floor reinforced concrete silo and floor steel silo)are established,and the parametric analysis is carried out.The acceleration response,displacement response and energy dissipation performance of the structure are analyzed.The results show that the silo structure with large ratio of height to diameter has greater seismic response.The seismic response of steel plate silo structure is greater than that of reinforced concrete silo structure.(4)The calculation formulas of absolute peak acceleration,amplification coefficient of acceleration,relative peak displacement and dynamic lateral pressure of silo under different loading conditions are fitted by Matlab software.The results show that the effect of increasing PGA and measuring point height is greater than that of increasing measuring point height under empty,half and full silo conditions.The research results can provide theoretical guidance for future silo design.