针对一种储罐在一定装液量下的地震瞬态响应进行分析探讨。使用CFD(Computational Fluid Dynamics)和FEM(Finite Element Method)耦合的数值分析方法进行计算,考虑气液两相黏性湍流态流体与结构之间的相互作用,获得了一定液体装量下该...针对一种储罐在一定装液量下的地震瞬态响应进行分析探讨。使用CFD(Computational Fluid Dynamics)和FEM(Finite Element Method)耦合的数值分析方法进行计算,考虑气液两相黏性湍流态流体与结构之间的相互作用,获得了一定液体装量下该容器在典型地震历程下的液体自由表面变化和结构响应特性。结果表明:在典型地震时程作用下,容器结构的响应由初始的小幅振动发展为高幅值振动,随着流固相互作用的充分发展,容器响应受液体晃动主导。通过比较无耦合的附加质量方法和流固耦合方法之间的差异,验证了耦合法在计算储罐地震响应问题上的优势,研究结果可以为工程安全分析提供参考和支持。展开更多
A computational framework for parachute inflation is developed based on the immersed boundary/finite element approach within the open-source IBAMR library.The fluid motion is solved by Peskin's diffuse-interface i...A computational framework for parachute inflation is developed based on the immersed boundary/finite element approach within the open-source IBAMR library.The fluid motion is solved by Peskin's diffuse-interface immersed boundary(IB)method,which is attractive for simulating moving-boundary flows with large deformations.The adaptive mesh refinement technique is employed to reduce the computational cost while retain the desired resolution.The dynamic response of the parachute is solved with the finite element approach.The canopy and cables of the parachute system are modeled with the hyperelastic material.A tether force is introduced to impose rigidity constraints for the parachute system.The accuracy and reliability of the present framework is validated by simulating inflation of a constrained square plate.Application of the present framework on several canonical cases further demonstrates its versatility for simulation of parachute inflation.展开更多
The data information transfer and time marching strategies between computational fluid dynamics （CFD） and computational structural dynamics （CSD） play crucial roles on the aeroelastic analysis in a time domain. An...The data information transfer and time marching strategies between computational fluid dynamics （CFD） and computational structural dynamics （CSD） play crucial roles on the aeroelastic analysis in a time domain. An improved CFD/CSD coupled system is designed, including an interpolation method and an improved loosely coupled algorithm. The interpolation method based on boundary element method （BEM） is developed to transfer aerodynamic loads and structural displacements between CFD and CSD grid systems, it can be universally used in fluid structural interaction solution by keeping energy conservation. The improved loosely coupled algo-rithm is designed, thus it improves the computational accuracy and efficiency. The new interface is performed on the two-dimensional （2-D） extrapolation and the aeroelastie response of AGARD445.6 wing. Results show that the improved interface has a superior accuracy.展开更多
According to the characteristics of thin-layer rolling and pouting construction technology and the complicated mechanical behavior of the roller compacted concrete dam （RCCD） construction interface, a constitutive m...According to the characteristics of thin-layer rolling and pouting construction technology and the complicated mechanical behavior of the roller compacted concrete dam （RCCD） construction interface, a constitutive model of endochronic damage was established based on the endochronic theory and damage mechanics. The proposed model abandons the traditional concept of elastic-plastic yield surface and can better reflect the real behavior of rolled control concrete. Basic equations were proposed for the fluid-solid coupling analysis, and the relationships among the corresponding key physical parameters were also put forward. One three-dimensional finite element method （FEM） program was obtained by studying the FEM type of the seepage-stress coupling intersection of the RCCD. The method was applied to an actual project, and the results show that the fluid-solid interaction influences dam deformation and dam abutment stability, which is in accordance with practice. Therefore, this model provides a new method for revealing the mechanical behavior of RCCD under the coupling field.展开更多
Drug delivery systems able to deliver the required dose of the drug to the target level use active or passive nano metric designed systems. In the earlier researches, carbon nanocones are used for transferring the ser...Drug delivery systems able to deliver the required dose of the drug to the target level use active or passive nano metric designed systems. In the earlier researches, carbon nanocones are used for transferring the serum to damaged proteins and damaged cancer cellules. In this lecture, stability analysis of drug delivery to damaged cancer cellutes is studied in the shape of single-walled carbon nanocone. In this method, each atom is considered as node and interactions between them are supposed as 3D-beam elements. By supposing that potential energy in macro relations is equal to the nano relations, nano-drug characteristics can be calculated. Then shape functions can be extracted to use in blood＇s FEM model and using reduced-order method, divergence velocities of carbon nanocone can be found. In this lecture, carbon nanocones are modeled with different dimensions and boundary conditions and stability of them in blood flow is studied and optimized carbon nanocone is selected in blood flow. Results show that conical nano-drug structures have more efficiency in blood flow rather than tube nano-drug structures and by increasing length of carbon nanocones, dimensionless stability parameter decreased and by increasing declination angle of carbon nanocones, dimensionless stability parameter increased.展开更多
文摘针对一种储罐在一定装液量下的地震瞬态响应进行分析探讨。使用CFD(Computational Fluid Dynamics)和FEM(Finite Element Method)耦合的数值分析方法进行计算,考虑气液两相黏性湍流态流体与结构之间的相互作用,获得了一定液体装量下该容器在典型地震历程下的液体自由表面变化和结构响应特性。结果表明:在典型地震时程作用下,容器结构的响应由初始的小幅振动发展为高幅值振动,随着流固相互作用的充分发展,容器响应受液体晃动主导。通过比较无耦合的附加质量方法和流固耦合方法之间的差异,验证了耦合法在计算储罐地震响应问题上的优势,研究结果可以为工程安全分析提供参考和支持。
基金supported by the Open Project of Key Laboratory of Aerospace EDLA,CASC(No.EDL19092208)。
文摘A computational framework for parachute inflation is developed based on the immersed boundary/finite element approach within the open-source IBAMR library.The fluid motion is solved by Peskin's diffuse-interface immersed boundary(IB)method,which is attractive for simulating moving-boundary flows with large deformations.The adaptive mesh refinement technique is employed to reduce the computational cost while retain the desired resolution.The dynamic response of the parachute is solved with the finite element approach.The canopy and cables of the parachute system are modeled with the hyperelastic material.A tether force is introduced to impose rigidity constraints for the parachute system.The accuracy and reliability of the present framework is validated by simulating inflation of a constrained square plate.Application of the present framework on several canonical cases further demonstrates its versatility for simulation of parachute inflation.
基金Supported by the Ph.D.Program Foundation of Ministry of Education of China (20070699054)~~
文摘The data information transfer and time marching strategies between computational fluid dynamics （CFD） and computational structural dynamics （CSD） play crucial roles on the aeroelastic analysis in a time domain. An improved CFD/CSD coupled system is designed, including an interpolation method and an improved loosely coupled algorithm. The interpolation method based on boundary element method （BEM） is developed to transfer aerodynamic loads and structural displacements between CFD and CSD grid systems, it can be universally used in fluid structural interaction solution by keeping energy conservation. The improved loosely coupled algo-rithm is designed, thus it improves the computational accuracy and efficiency. The new interface is performed on the two-dimensional （2-D） extrapolation and the aeroelastie response of AGARD445.6 wing. Results show that the improved interface has a superior accuracy.
基金Projects(51139001,51179066,51079046,50909041) supported by the National Natural Science Foundation of ChinaProject(NCET-10-0359) supported by the Program for New Century Excellent Talents in UniversityProjects(2009586012,2009586912,2010585212)supported by the Special Fund of State Key Laboratory of China
文摘According to the characteristics of thin-layer rolling and pouting construction technology and the complicated mechanical behavior of the roller compacted concrete dam （RCCD） construction interface, a constitutive model of endochronic damage was established based on the endochronic theory and damage mechanics. The proposed model abandons the traditional concept of elastic-plastic yield surface and can better reflect the real behavior of rolled control concrete. Basic equations were proposed for the fluid-solid coupling analysis, and the relationships among the corresponding key physical parameters were also put forward. One three-dimensional finite element method （FEM） program was obtained by studying the FEM type of the seepage-stress coupling intersection of the RCCD. The method was applied to an actual project, and the results show that the fluid-solid interaction influences dam deformation and dam abutment stability, which is in accordance with practice. Therefore, this model provides a new method for revealing the mechanical behavior of RCCD under the coupling field.
文摘Drug delivery systems able to deliver the required dose of the drug to the target level use active or passive nano metric designed systems. In the earlier researches, carbon nanocones are used for transferring the serum to damaged proteins and damaged cancer cellules. In this lecture, stability analysis of drug delivery to damaged cancer cellutes is studied in the shape of single-walled carbon nanocone. In this method, each atom is considered as node and interactions between them are supposed as 3D-beam elements. By supposing that potential energy in macro relations is equal to the nano relations, nano-drug characteristics can be calculated. Then shape functions can be extracted to use in blood＇s FEM model and using reduced-order method, divergence velocities of carbon nanocone can be found. In this lecture, carbon nanocones are modeled with different dimensions and boundary conditions and stability of them in blood flow is studied and optimized carbon nanocone is selected in blood flow. Results show that conical nano-drug structures have more efficiency in blood flow rather than tube nano-drug structures and by increasing length of carbon nanocones, dimensionless stability parameter decreased and by increasing declination angle of carbon nanocones, dimensionless stability parameter increased.
