粮食散料-钢板筒仓耦合动力行为与地震响应机理研究

The mechanical properties and constitutive model of grain granular materials are studied by drawing constitutive theory for granular soil. Based on experiments, theoretic analysis and numerical simulation, it studies the coupling dynamic behaviors, seismic response mechanism and calculation theory of steel silos containing grain-like materials. Main contents of this topic are as follows: firstly, the deformation and mechanical properties of grain granular materials are analyzed according to experimental results, and the dynamic elastic modulus and damping ratio are also determined. Then, the dynamic constitutive model of grain is established based on the hypoplastic model. Based on shaking table test of silo model, the numerical analysis model of steel silo containing grain-like materials is established. It is revealed that the interaction mechanism between grain granular materials and steel silo, including the stress distribution and failure mode of steel silo. And dynamic response evolution of steel silos containing grain-like materials is also analyzed. On the basis of the above, a simplified calculation model will be established to study seismic response of steel silos containing grain-like materials, and then the calculation formula of seismic bearing capacity is proposed. The research aims to solve the key technical problems for grain steel silos in seismic regions, providing experimental basis and theoretical reference for further engineering application of steel silos.

借鉴散粒型土体本构理论，研究粮食散体材料的力学性质并建立本构模型，采用试验研究、理论分析和数值模拟相结合的方法，系统研究粮食散料-钢板筒仓体系的耦合动力行为、地震响应机理和计算理论等关键问题。主要研究内容包括：基于试验结果，研究粮食散体材料的变形和力学性质，确定仓内粮食动弹性模量和阻尼比特性，修正和完善亚塑性模型参数，建立粮食散料动本构模型；在筒仓模型振动台试验的基础上，建立粮食散料-钢板筒仓体系精细化数值分析模型，基于试验和数值拓展分析，揭示地震作用下粮食散料与钢板筒仓相互作用机理，探明筒仓应力分布规律和破坏模式，分析粮食散料-钢板筒仓体系的动力响应演化规律；基于试验、数值模拟和理论分析结果，构建粮食散料-钢板筒仓体系地震作用简化计算模型，提出实用的抗震承载能力计算公式。研究成果旨在解决地震区粮食钢板筒仓应用的关键技术问题，为钢板筒仓的深入工程应用提供试验依据及理论基础。

针对目前粮食钢板筒仓抗震研究成果不系统、粮食散体材料力学特性与本构关系缺乏相关依据，难以满足实际工程多样化及复杂化的研究现状，本项目采用试验研究、数值模拟与理论分析相结合的方法，对粮食散体材料的力学性质、粮-仓体系的地震响应机理和抗震计算理论进行系统的研究。通过试验研究了小麦和大豆粮堆单元体的强度和应力-应变规律，并确定了关键物理力学参数的取值；开展了一系列分级循环加载条件下的动三轴试验，揭示了粮食散体材料动弹性模量和阻尼比随振次、围压及动应变幅值的变化规律；探究了非线性弹性模型和等效线性黏弹性模型对粮食散料的适用性；基于Darvidenkov模型描述粮食散料的动应力应变关系，并确定了模型参数。通过对粮食散料-钢板筒仓有限元模型进行不同工况下的地震作用数值模拟和算例分析，考虑不同加载型式、不同储料高度、筒仓高径比及径厚比、支承型式等各参数的变化，获得筒仓的应力分布云图、粮-仓体系加速度（位移）时程曲线，破坏模式等计算结果。建立了粮食散料-钢板筒仓体系精细化数值分析模型，基于振动台模型试验和数值拓展分析，揭示了地震作用下粮食散料与钢板筒仓相互作用机理；探明了筒仓应力分布规律和破坏模式，分析了粮食散料-钢板筒仓体系的动力响应演化规律，揭示了仓壁动侧压力的分布及竖向摩擦力的影响规律。