论文部分内容阅读
饱和岩土类多孔材料内固、液相不同属性产生的各向异性和多孔微结构的不均匀性使得材料的细观力学特性计算变得十分复杂。为准确预测岩土类材料的有效弹性性能和细观应力-应变场,基于Biot多孔弹性介质理论,建立可描述岩土类多孔材料固液相运动的能量泛函和相应的多孔弹性本构关系;利用细、宏观尺度比作为小参数将能量变分泛函渐近扩展为系列近似泛函;以场变量波动函数为未知量,通过解决近似泛函的最小化问题(驻值问题)得到波动函数的解析解,从而建立逼近物理和工程真实性的细观力学模型,并通过有限元技术得以数值实现。多孔介质材料细观力学特性算例表明:与经典均匀化理论(将液体类比为具有较高泊松比的固体材料)相比,基于变分渐近均匀化细观模型预测的多孔介质材料细观力学特性更精确,尤其是能准确重构多孔微结构内局部应力-应变场分布,为损伤破坏、局部断裂分析奠定了坚实基础。
The anisotropy due to different properties of the solid and liquid phases in saturated geotechnical porous materials and the inhomogeneity of the porous microstructure make the calculation of the mesoscopic mechanical properties of the material complicated. In order to accurately predict the effective elastic properties and the mesomechanical stress-strain field of geomaterials, an energy functional theory describing the solid-liquid phase motion of the geomaterial porous material and the corresponding porous elastic constitutive relationship are established based on the Biot porous elastic media theory ; Using the fine and macro scale ratios as small parameters, the energy functional asymptotic expansion to a series of approximate functional; the volatility function of the field variable as the unknown, by solving the problem of minimization of approximation function Function analytic solution to establish a micro-mechanics model that approximates the physical and engineering authenticity and is realized numerically by the finite element method. The numerical examples of the meso - mechanical properties of porous media show that compared with the classical theory of homogenization (liquid analogy with solid material with higher Poisson ’s ratio), the porous media material based on the variational asymptotic homogenization model The observational mechanics properties are more accurate. Especially, the local stress-strain field distribution in the porous microstructure can be accurately reconstructed, which lays a solid foundation for damage and local fracture analysis.