Due to the influence of deep-sea environment,deep-sea sediments are usually heterogeneous,and their moduli of elasticity and density change as depth changes.Combined with the characteristics of deep-sea sediments,the ...Due to the influence of deep-sea environment,deep-sea sediments are usually heterogeneous,and their moduli of elasticity and density change as depth changes.Combined with the characteristics of deep-sea sediments,the thermo-hydro-mechanical coupling dynamic response model of heterogeneous saturated porous sediments can be established to study the influence of elastic modulus,density,frequency,and load amplitude changes on the model.Based on the Green-Lindsay generalized thermoelasticity theory and Darcy’s law,the thermo-hydro-mechanical coupled dynamic response model and governing equations of heterogeneous deep-sea sediments with nonlinear elastic modulus and density are established.The analytical solutions of dimensionless vertical displacement,vertical stress,excess pore water pressure,and temperature are obtained by means of normal modal analysis,which are depicted graphically.The results show that the changes of elastic modulus and density have few effects on vertical displacement,vertical stress,and temperature,but have great effects on excess pore water pressure.When the mining machine vibrates,the heterogeneity of deep-sea sediments has great influence on vertical displacement,vertical stress,and excess pore water pressure,but has few effects on temperature.In addition,the vertical displacement,vertical stress,and excess pore water pressure of heterogeneous deep-sea sediments change more gently.The variation trends of physical quantities for heterogeneous and homogeneous deep-sea sediments with frequency and load amplitude are basically the same.The results can provide theoretical guidance for deep-sea mining engineering construction.展开更多
The importance of study on constitutive model of statically loaded rock experiencing dynamic load is set forth, and the studying methods on dynamic constitutive model are classified according to the current studying s...The importance of study on constitutive model of statically loaded rock experiencing dynamic load is set forth, and the studying methods on dynamic constitutive model are classified according to the current studying status. By way of combining statistic damage model and viscoelastic model, uni-axial and multi-axial constitutive models of statically loaded rock experiencing dynamic load (static-dynamic coupling constitutive model) under intermediate strain rate are established. The verification experiment on 2D constitutive model under different static stress and dynamic stress with different frequencies is designed and performed. It is found that there is a good agreement between the experimental stress-strain curves and the theoretical stress-strain curves.展开更多
A revised flexible roller contact tire model (RFRC tire model) is proposed, which considers not only the geometric and flexible filtering effect, but also tire damping and pavement displacement. A vehi- cle-pavement c...A revised flexible roller contact tire model (RFRC tire model) is proposed, which considers not only the geometric and flexible filtering effect, but also tire damping and pavement displacement. A vehi- cle-pavement coupled system is modeled as a two DOF oscillator moving along a simply supported beam on a linear viscoelastic foundation. By using the Galerkin’s and Direct Integral method, dynamical responses of the vehicle-pavement coupled system are obtained based on the RFRC tire model and the traditional single point contact tire model (SPC tire model). The simulation results are compared with test data and the validity of the proposed RFRC tire model is verified. Differences between the two models are also investigated. It is found that the dynamical behaviors for both models agree with each other quite well when road surface roughness is a long harmonic wave. On the other hand, they are different under short harmonic wave or impulse road excitation. Thus the RFRC tire model should be used to compute the tire force and investigate dynamical responses of vehicle and pavement.展开更多
为分析中耳软组织粘弹性材料特性对人耳系统动力学特性影响,建立包括外耳道、中耳及耳蜗的整耳有限元模型。外耳道及中耳模型用微CT扫描与逆向成型技术建立,耳蜗采用双腔导管形式简化模型。基于该模型,中耳部分软组织材料属性采用线性...为分析中耳软组织粘弹性材料特性对人耳系统动力学特性影响,建立包括外耳道、中耳及耳蜗的整耳有限元模型。外耳道及中耳模型用微CT扫描与逆向成型技术建立,耳蜗采用双腔导管形式简化模型。基于该模型,中耳部分软组织材料属性采用线性粘弹性,以表征动态分析中能量损耗。在外耳道施加90 d B SPL声压模拟声激励,并在计算中考虑外耳道气体、中耳固体及耳蜗流体多场耦合作用。中耳结构响应包括鼓膜脐部与镫骨底板位移及镫骨底板速度传递函数,耳蜗流体压力响应用于计算中耳压力增益、耳蜗输入声阻抗及压力逆向传递函数。结果表明,考虑粘弹性后,人耳系统动态响应参数较线弹性有一定程度改善,尤其在高频段提升较明显,与实验测量数据匹配效果更好。展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.12072309,61603322)。
文摘Due to the influence of deep-sea environment,deep-sea sediments are usually heterogeneous,and their moduli of elasticity and density change as depth changes.Combined with the characteristics of deep-sea sediments,the thermo-hydro-mechanical coupling dynamic response model of heterogeneous saturated porous sediments can be established to study the influence of elastic modulus,density,frequency,and load amplitude changes on the model.Based on the Green-Lindsay generalized thermoelasticity theory and Darcy’s law,the thermo-hydro-mechanical coupled dynamic response model and governing equations of heterogeneous deep-sea sediments with nonlinear elastic modulus and density are established.The analytical solutions of dimensionless vertical displacement,vertical stress,excess pore water pressure,and temperature are obtained by means of normal modal analysis,which are depicted graphically.The results show that the changes of elastic modulus and density have few effects on vertical displacement,vertical stress,and temperature,but have great effects on excess pore water pressure.When the mining machine vibrates,the heterogeneity of deep-sea sediments has great influence on vertical displacement,vertical stress,and excess pore water pressure,but has few effects on temperature.In addition,the vertical displacement,vertical stress,and excess pore water pressure of heterogeneous deep-sea sediments change more gently.The variation trends of physical quantities for heterogeneous and homogeneous deep-sea sediments with frequency and load amplitude are basically the same.The results can provide theoretical guidance for deep-sea mining engineering construction.
基金Projects(10472134 50490274+1 种基金 50174056) supported by the National Natural Science Foundation of China Project(2005038250) supported by China Postdoctoral Science Foundation
文摘The importance of study on constitutive model of statically loaded rock experiencing dynamic load is set forth, and the studying methods on dynamic constitutive model are classified according to the current studying status. By way of combining statistic damage model and viscoelastic model, uni-axial and multi-axial constitutive models of statically loaded rock experiencing dynamic load (static-dynamic coupling constitutive model) under intermediate strain rate are established. The verification experiment on 2D constitutive model under different static stress and dynamic stress with different frequencies is designed and performed. It is found that there is a good agreement between the experimental stress-strain curves and the theoretical stress-strain curves.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 10672107, 50625518)the Natural Science Foundation of Hebei Province (Grant No. E2007000657)
文摘A revised flexible roller contact tire model (RFRC tire model) is proposed, which considers not only the geometric and flexible filtering effect, but also tire damping and pavement displacement. A vehi- cle-pavement coupled system is modeled as a two DOF oscillator moving along a simply supported beam on a linear viscoelastic foundation. By using the Galerkin’s and Direct Integral method, dynamical responses of the vehicle-pavement coupled system are obtained based on the RFRC tire model and the traditional single point contact tire model (SPC tire model). The simulation results are compared with test data and the validity of the proposed RFRC tire model is verified. Differences between the two models are also investigated. It is found that the dynamical behaviors for both models agree with each other quite well when road surface roughness is a long harmonic wave. On the other hand, they are different under short harmonic wave or impulse road excitation. Thus the RFRC tire model should be used to compute the tire force and investigate dynamical responses of vehicle and pavement.
文摘为分析中耳软组织粘弹性材料特性对人耳系统动力学特性影响,建立包括外耳道、中耳及耳蜗的整耳有限元模型。外耳道及中耳模型用微CT扫描与逆向成型技术建立,耳蜗采用双腔导管形式简化模型。基于该模型,中耳部分软组织材料属性采用线性粘弹性,以表征动态分析中能量损耗。在外耳道施加90 d B SPL声压模拟声激励,并在计算中考虑外耳道气体、中耳固体及耳蜗流体多场耦合作用。中耳结构响应包括鼓膜脐部与镫骨底板位移及镫骨底板速度传递函数,耳蜗流体压力响应用于计算中耳压力增益、耳蜗输入声阻抗及压力逆向传递函数。结果表明,考虑粘弹性后,人耳系统动态响应参数较线弹性有一定程度改善,尤其在高频段提升较明显,与实验测量数据匹配效果更好。
