The pullout testing of geosynthetics is essential for studying interface interaction in the soil-reinforcement system. In this paper, a new method for testing interface properties of geotextiles is proposed. The inter...The pullout testing of geosynthetics is essential for studying interface interaction in the soil-reinforcement system. In this paper, a new method for testing interface properties of geotextiles is proposed. The interface frictional characters of two kinds of geotextiles (woven and needle-punched nonwoven) are investigated through pullout test. Nonwoven specimen has more wide variety of displacement along length than that of woven under the same pressure because of their different extensibility. The greater the elongation and deformation of specimens, the more evident the variations of displacement along reinforcement from front to pullout end. The greater the normal pressure, the smaller the displacement of every position along length with the same pullout load. The study focuses on the effects of the tensile modulus and the difference of pullout response between woven and nonwoven geotextiles.展开更多
According to the data of the experiment made in mechanical tensile of Polycarbonate in high temperature, experiments were done to polycarbonate sheet by hot gas pressure bulge-forming. It was found that selecting and ...According to the data of the experiment made in mechanical tensile of Polycarbonate in high temperature, experiments were done to polycarbonate sheet by hot gas pressure bulge-forming. It was found that selecting and combination of the processing parameters were vital to the quality. In the experiments and numerical simulation with the software of DYNAFORM, the processing parameters have been studied.The results showed that the method of discontinuous pressure and pressure preservation advantage the forming; when temperature and pressure meet the forming conditions, the longer time of pressure preservation promotes sufficient forming.展开更多
This study aims to develop a model to characterize the inhomogeneous material deformation behavior in micro-forming.First,the influence of individual grain heterogeneity on the deformation behavior of CuZn20 foils was...This study aims to develop a model to characterize the inhomogeneous material deformation behavior in micro-forming.First,the influence of individual grain heterogeneity on the deformation behavior of CuZn20 foils was investigated via tensile and micro-hardness tests.The results showed that different from thick sheets,the hardening behavior of grains in the deformation area of thin foils is not uniform.The flow stress of thin foils actually only reflects the average hardening behavior of several easy-deformation-grains,which is the reason that thinner foils own smaller flow stress.Then,a composite modeling method under consideration of individual grain heterogeneity was developed,where the effects of grain orientation and shape are quantitatively represented by the method of flow stress classification and Voronoi tessellation,respectively.This model provides an accurate and effective method to analyze the influence of individual grain heterogeneity on the deformation behavior of the micro-sized material.展开更多
The stiffness reduction is studied in detail of compact W-Shapes （wide-flange steel shapes） that results from yielding of the cross-section due to uniaxial bending and axial compression. Three-dimensional m-p-τ su...The stiffness reduction is studied in detail of compact W-Shapes （wide-flange steel shapes） that results from yielding of the cross-section due to uniaxial bending and axial compression. Three-dimensional m-p-τ surface plots developed from detailed fiber element models of a W8x31 are used to develop a generalized material model for direct implementation in the virtual work method. A portal steel frame is used to illustrate the virtual work method with the nonlinear material model in a first-order, inelastic analysis implementation and in a second-order, inelastic analysis condition. The nonlinear modeling capabilities of MASTAN2 are used to verify the accuracy of the virtual work results and are found to be in very close agreement.展开更多
A giant magnetostrictive material (GMM) model is developed based on the hysteretic nonlinear theory. The Gram-Schmidt regression method is introduced to determine the parameters of the model as well as the relation- s...A giant magnetostrictive material (GMM) model is developed based on the hysteretic nonlinear theory. The Gram-Schmidt regression method is introduced to determine the parameters of the model as well as the relation- ship between the material strain and the strength and frequency of magnetic field in the model. Through comparison, it is shown that this regression method has good performance in significance test. Then the model is applied to study the motion law of a circular plate in classical GMM transducer, which helps control the transducer rapidly and accurately.展开更多
文摘The pullout testing of geosynthetics is essential for studying interface interaction in the soil-reinforcement system. In this paper, a new method for testing interface properties of geotextiles is proposed. The interface frictional characters of two kinds of geotextiles (woven and needle-punched nonwoven) are investigated through pullout test. Nonwoven specimen has more wide variety of displacement along length than that of woven under the same pressure because of their different extensibility. The greater the elongation and deformation of specimens, the more evident the variations of displacement along reinforcement from front to pullout end. The greater the normal pressure, the smaller the displacement of every position along length with the same pullout load. The study focuses on the effects of the tensile modulus and the difference of pullout response between woven and nonwoven geotextiles.
基金Sponsored by the Scientific Research Foundation of Harbin Institute of Technology(Grant No.HIT.2000.65).
文摘According to the data of the experiment made in mechanical tensile of Polycarbonate in high temperature, experiments were done to polycarbonate sheet by hot gas pressure bulge-forming. It was found that selecting and combination of the processing parameters were vital to the quality. In the experiments and numerical simulation with the software of DYNAFORM, the processing parameters have been studied.The results showed that the method of discontinuous pressure and pressure preservation advantage the forming; when temperature and pressure meet the forming conditions, the longer time of pressure preservation promotes sufficient forming.
基金Project(51905362)supported by the National Natural Science Foundation of ChinaProjects(19KJB460022,18KJB130006)supported by the Natural Science Foundation of Jiangsu Higher Education Institution,China。
文摘This study aims to develop a model to characterize the inhomogeneous material deformation behavior in micro-forming.First,the influence of individual grain heterogeneity on the deformation behavior of CuZn20 foils was investigated via tensile and micro-hardness tests.The results showed that different from thick sheets,the hardening behavior of grains in the deformation area of thin foils is not uniform.The flow stress of thin foils actually only reflects the average hardening behavior of several easy-deformation-grains,which is the reason that thinner foils own smaller flow stress.Then,a composite modeling method under consideration of individual grain heterogeneity was developed,where the effects of grain orientation and shape are quantitatively represented by the method of flow stress classification and Voronoi tessellation,respectively.This model provides an accurate and effective method to analyze the influence of individual grain heterogeneity on the deformation behavior of the micro-sized material.
文摘The stiffness reduction is studied in detail of compact W-Shapes （wide-flange steel shapes） that results from yielding of the cross-section due to uniaxial bending and axial compression. Three-dimensional m-p-τ surface plots developed from detailed fiber element models of a W8x31 are used to develop a generalized material model for direct implementation in the virtual work method. A portal steel frame is used to illustrate the virtual work method with the nonlinear material model in a first-order, inelastic analysis implementation and in a second-order, inelastic analysis condition. The nonlinear modeling capabilities of MASTAN2 are used to verify the accuracy of the virtual work results and are found to be in very close agreement.
基金Doctoral Programs Foundation of Ministry of Education of China (No. 200800561083)
文摘A giant magnetostrictive material (GMM) model is developed based on the hysteretic nonlinear theory. The Gram-Schmidt regression method is introduced to determine the parameters of the model as well as the relation- ship between the material strain and the strength and frequency of magnetic field in the model. Through comparison, it is shown that this regression method has good performance in significance test. Then the model is applied to study the motion law of a circular plate in classical GMM transducer, which helps control the transducer rapidly and accurately.
