The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Fu Liu - One of the best experts on this subject based on the ideXlab platform.
-
a modified johnson cook model of dynamic Tensile behaviors for 7075 t6 aluminum alloy
Journal of Alloys and Compounds, 2015Co-Authors: Ding-ni Zhang, Qian-qian Shangguan, Can-jun Xie, Fu LiuAbstract:Abstract The dynamic mechanical behaviors of 7075-T6 aluminum alloy at various strain rates were measured by dynamic Tensile tests using the electronic universal testing machine, high velocity testing system and split Hopkinson Tensile Bar (SHTB). Stress–strain curves at different rates were obtained. The results show that the strain rate hardening effect of 7075-T6 aluminum alloy is significant. By modifying the strain rate hardening term in the Johnson–Cook constitutive model, a new Johnson–Cook (JC) constitutive model of 7075-T6 aluminum alloy was obtained. The improved Johnson–Cook model matched the experiment results very well. With the Johnson–Cook constitutive model, numerical simulations of Tensile tests at different rates for 7075-T6 aluminum alloy were conducted. According to Tensile loading and stress–strain relation of 7075-T6 aluminum alloy, calculation results were compared with experimental results. Accuracy of the modified Johnson–Cook constitutive equation was further proved.
-
A modified Johnson–Cook model of dynamic Tensile behaviors for 7075-T6 aluminum alloy
Journal of Alloys and Compounds, 2015Co-Authors: Ding-ni Zhang, Qian-qian Shangguan, Can-jun Xie, Fu LiuAbstract:Abstract The dynamic mechanical behaviors of 7075-T6 aluminum alloy at various strain rates were measured by dynamic Tensile tests using the electronic universal testing machine, high velocity testing system and split Hopkinson Tensile Bar (SHTB). Stress–strain curves at different rates were obtained. The results show that the strain rate hardening effect of 7075-T6 aluminum alloy is significant. By modifying the strain rate hardening term in the Johnson–Cook constitutive model, a new Johnson–Cook (JC) constitutive model of 7075-T6 aluminum alloy was obtained. The improved Johnson–Cook model matched the experiment results very well. With the Johnson–Cook constitutive model, numerical simulations of Tensile tests at different rates for 7075-T6 aluminum alloy were conducted. According to Tensile loading and stress–strain relation of 7075-T6 aluminum alloy, calculation results were compared with experimental results. Accuracy of the modified Johnson–Cook constitutive equation was further proved.
Ding-ni Zhang - One of the best experts on this subject based on the ideXlab platform.
-
a modified johnson cook model of dynamic Tensile behaviors for 7075 t6 aluminum alloy
Journal of Alloys and Compounds, 2015Co-Authors: Ding-ni Zhang, Qian-qian Shangguan, Can-jun Xie, Fu LiuAbstract:Abstract The dynamic mechanical behaviors of 7075-T6 aluminum alloy at various strain rates were measured by dynamic Tensile tests using the electronic universal testing machine, high velocity testing system and split Hopkinson Tensile Bar (SHTB). Stress–strain curves at different rates were obtained. The results show that the strain rate hardening effect of 7075-T6 aluminum alloy is significant. By modifying the strain rate hardening term in the Johnson–Cook constitutive model, a new Johnson–Cook (JC) constitutive model of 7075-T6 aluminum alloy was obtained. The improved Johnson–Cook model matched the experiment results very well. With the Johnson–Cook constitutive model, numerical simulations of Tensile tests at different rates for 7075-T6 aluminum alloy were conducted. According to Tensile loading and stress–strain relation of 7075-T6 aluminum alloy, calculation results were compared with experimental results. Accuracy of the modified Johnson–Cook constitutive equation was further proved.
-
A modified Johnson–Cook model of dynamic Tensile behaviors for 7075-T6 aluminum alloy
Journal of Alloys and Compounds, 2015Co-Authors: Ding-ni Zhang, Qian-qian Shangguan, Can-jun Xie, Fu LiuAbstract:Abstract The dynamic mechanical behaviors of 7075-T6 aluminum alloy at various strain rates were measured by dynamic Tensile tests using the electronic universal testing machine, high velocity testing system and split Hopkinson Tensile Bar (SHTB). Stress–strain curves at different rates were obtained. The results show that the strain rate hardening effect of 7075-T6 aluminum alloy is significant. By modifying the strain rate hardening term in the Johnson–Cook constitutive model, a new Johnson–Cook (JC) constitutive model of 7075-T6 aluminum alloy was obtained. The improved Johnson–Cook model matched the experiment results very well. With the Johnson–Cook constitutive model, numerical simulations of Tensile tests at different rates for 7075-T6 aluminum alloy were conducted. According to Tensile loading and stress–strain relation of 7075-T6 aluminum alloy, calculation results were compared with experimental results. Accuracy of the modified Johnson–Cook constitutive equation was further proved.
Patricia Verleysen - One of the best experts on this subject based on the ideXlab platform.
-
effect of strain rate on the forming behaviour of sheet metals
Journal of Materials Processing Technology, 2011Co-Authors: Patricia Verleysen, Jos Van Slycken, Jan Peirs, Koen Faes, Laurent DucheneAbstract:Abstract The strain rate dependence of plastic yield and failure properties displayed by most metals affects energies, forces and forming limits involved in high speed forming processes. This paper investigates the influence of the strain rate on the forming properties of one laboratory made and three commercial steel grades: a CMnAl TRIP steel, the ferritic structural steel S235JR, the drawing steel DC04 and the ferritic stainless steel AISI 409. First, split Hopkinson Tensile Bar (SHTB) experiments are carried out to assess the influence of the strain rate on the materials’ stress–strain curves. Subsequently, the obtained SHTB results, together with static Tensile test results, are used to model the constitutive behaviour of the investigated steels using the phenomenological Johnson–Cook (JC) model and the Voce model, thus allowing dynamic modelling of forming processes. Finally, forming limit diagrams (FLDs) are calculated using the Marciniak–Kuczynski method. The results clearly show that the effect of the strain rate on forces and energies involved in a forming process, and the forming limits is non-negligible and strongly material dependent.
-
numerical study of the influence of the specimen geometry on split hopkinson Bar Tensile test results
Latin American Journal of Solids and Structures, 2009Co-Authors: Patricia Verleysen, Benedict Verhegghe, Tom Verstraete, Joris DegrieckAbstract:FINITE ELEMENT SIMULATIONS OF HIGH STRAIN RATE Tensile EXPERIMENTS ON SHEET MATERIALS USING DIFFERENT SPECIMEN GEOMETRIES ARE PRESENTED. THE SIMULATIONS COMPLEMENT AN EXPERIMENTAL STUDY, USING A SPLIT HOPKINSON Tensile Bar SET-UP, COUPLED WITH A FULL-FIELD DEFORMATION MEASUREMENT DEVICE. THE SIMULATIONS GIVE DETAILED INFORMATION ON THE STRESS STATE. DUE TO THE SMALL SIZE OF THE SPECIMENS AND THE WAY THEY ARE CONNECTED TO THE TEST DEVICE, NON-AXIAL STRESSES DEVELOP DURING LOADING. THESE STRESS COMPONENTS ARE COMMONLY NEGLECTED, BUT, AS WILL BE SHOWN, HAVE A DISTINCT INFLUENCE ON THE SPECIMEN BEHAVIOUR AND THE STRESS-STRAIN CURVE EXTRACTED FROM THE EXPERIMENT. THE VALIDITY OF THE BASIC ASSUMPTIONS OF HOPKINSON EXPERIMENTS IS INVESTIGATED: THE UNIAXIALITY OF THE STRESS STATE, THE HOMOGENEITY OF THE STRAIN AND THE NEGLIGIBLENESS OF THE DEFORMATION OF THE TRANSITION ZONES. THE INFLUENCE OF DEVIATIONS FROM THESE ASSUMPTIONS ON THE MATERIAL BEHAVIOUR EXTRACTED FROM A HOPKINSON EXPERIMENT IS DISCUSSED.
-
influence of specimen geometry on split hopkinson Tensile Bar tests on sheet materials
Experimental Mechanics, 2008Co-Authors: Patricia Verleysen, Thierry Verstraete, Joris Degrieck, Jos Van SlyckenAbstract:In recent years numerous studies on the high strain rate behaviour of sheet materials using split Hopkinson Tensile Bar set-ups have been reported in literature. For these experiments mostly dogbone-shaped specimens are used. However, widely divergent specimen dimensions can be found. In the present study the influence of this specimen geometry on the test results is investigated experimentally. An extensive series of Hopkinson tests on a steel sheet material using different specimen geometries is performed. An advanced optical technique is used to obtain the true distribution of the deformation along the length of the specimen. Important issues such as the contribution of the deformation of the transition zones to the total deformation and the (non-)homogeneity of the strain in the specimen are thus determined. From the experiments it is clear that the influence of the specimen geometry on the observed behaviour cannot be neglected. It is shown that inconsistencies between the assumed and real specimen behaviour account for these differences. For the TRIP steel considered in the study, accurate deformation values are only guaranteed if the length to width ratio of the central zone is larger than 1.25 and if the radius of the transition zone is sufficiently small.
-
The effect of silicon, aluminium and phosphor on the dynamic behavior and phenomenological modelling of multiphase TRIP steels
Metals and Materials International, 2007Co-Authors: Jos Van Slycken, Jeremy Bouquerel, Patricia Verleysen, Joris Degrieck, Bruno C. De CoomanAbstract:Multiphase TRansformation Induced Plasticity (TRIP) steels combine excellent ductility and high strength, making them ideally suited for shock absorbing parts in the automotive industry. When designing structures for impact, an understanding of the mechanical properties of materials under high strain rate conditions is essential. An extensive experimental program using a split Hopkinson Tensile Bar set-up was established in an effort to investigate the dynamic properties of various TRIP steel grades. Four different TRIP steels are described with varying contents of the alloying elements silicon, aluminium and phosphor. Moreover, several phenomenological models describing the strain rate and temperature-dependent mechanical behaviour are validated. TRIP steel grades in which aluminium is the main alloying element show high elongation values, whereas a high silicon content results in an increase in strength. The widely used Johnson-Cook model can describe the behaviour of TRIP steels and provides the opportunity to study its material and structural response.
-
Impact-dynamic behaviour of Al-TRIP steel
2005Co-Authors: Patricia Verleysen, Jos Van Slycken, Joris DegrieckAbstract:In recent years TRIP-steels (TRansformation Induced Plasticity-steels) have been developed. TRIP-steels are composite steels composed of ferrite, bainite and retained austenite. During plastic deformation, the austenite phase transforms to martensite, and this gives rise to an exceptional mechanical behaviour of the material: high strength levels (yield strength, Tensile strength, ...) are combined with an excellent ductility. The resulting high energy dissipation makes TRIP-steels extremely suitable for energy-absorbing devices such as the Bars used in the crumpling zone of a car. To guarantee a controlled dissipation of the energy released during a crash, knowledge and understanding of the impact-dynamic material properties is essential. In this contribution results of an extensive experimental program to investigate the strain rate dependent mechanical properties of a TRIP-Al-steel are presented. A split Hopkinson Tensile Bar set-up was used for the experiments. Next to the TRIP-material, also the three constituent phases of the TRIP-steel were produced and subjected to high strain rate loading. From the results it is clear that TRIP steels, also in dynamic circumstances, show excellent mechanical properties.
Qian-qian Shangguan - One of the best experts on this subject based on the ideXlab platform.
-
a modified johnson cook model of dynamic Tensile behaviors for 7075 t6 aluminum alloy
Journal of Alloys and Compounds, 2015Co-Authors: Ding-ni Zhang, Qian-qian Shangguan, Can-jun Xie, Fu LiuAbstract:Abstract The dynamic mechanical behaviors of 7075-T6 aluminum alloy at various strain rates were measured by dynamic Tensile tests using the electronic universal testing machine, high velocity testing system and split Hopkinson Tensile Bar (SHTB). Stress–strain curves at different rates were obtained. The results show that the strain rate hardening effect of 7075-T6 aluminum alloy is significant. By modifying the strain rate hardening term in the Johnson–Cook constitutive model, a new Johnson–Cook (JC) constitutive model of 7075-T6 aluminum alloy was obtained. The improved Johnson–Cook model matched the experiment results very well. With the Johnson–Cook constitutive model, numerical simulations of Tensile tests at different rates for 7075-T6 aluminum alloy were conducted. According to Tensile loading and stress–strain relation of 7075-T6 aluminum alloy, calculation results were compared with experimental results. Accuracy of the modified Johnson–Cook constitutive equation was further proved.
-
A modified Johnson–Cook model of dynamic Tensile behaviors for 7075-T6 aluminum alloy
Journal of Alloys and Compounds, 2015Co-Authors: Ding-ni Zhang, Qian-qian Shangguan, Can-jun Xie, Fu LiuAbstract:Abstract The dynamic mechanical behaviors of 7075-T6 aluminum alloy at various strain rates were measured by dynamic Tensile tests using the electronic universal testing machine, high velocity testing system and split Hopkinson Tensile Bar (SHTB). Stress–strain curves at different rates were obtained. The results show that the strain rate hardening effect of 7075-T6 aluminum alloy is significant. By modifying the strain rate hardening term in the Johnson–Cook constitutive model, a new Johnson–Cook (JC) constitutive model of 7075-T6 aluminum alloy was obtained. The improved Johnson–Cook model matched the experiment results very well. With the Johnson–Cook constitutive model, numerical simulations of Tensile tests at different rates for 7075-T6 aluminum alloy were conducted. According to Tensile loading and stress–strain relation of 7075-T6 aluminum alloy, calculation results were compared with experimental results. Accuracy of the modified Johnson–Cook constitutive equation was further proved.
Can-jun Xie - One of the best experts on this subject based on the ideXlab platform.
-
a modified johnson cook model of dynamic Tensile behaviors for 7075 t6 aluminum alloy
Journal of Alloys and Compounds, 2015Co-Authors: Ding-ni Zhang, Qian-qian Shangguan, Can-jun Xie, Fu LiuAbstract:Abstract The dynamic mechanical behaviors of 7075-T6 aluminum alloy at various strain rates were measured by dynamic Tensile tests using the electronic universal testing machine, high velocity testing system and split Hopkinson Tensile Bar (SHTB). Stress–strain curves at different rates were obtained. The results show that the strain rate hardening effect of 7075-T6 aluminum alloy is significant. By modifying the strain rate hardening term in the Johnson–Cook constitutive model, a new Johnson–Cook (JC) constitutive model of 7075-T6 aluminum alloy was obtained. The improved Johnson–Cook model matched the experiment results very well. With the Johnson–Cook constitutive model, numerical simulations of Tensile tests at different rates for 7075-T6 aluminum alloy were conducted. According to Tensile loading and stress–strain relation of 7075-T6 aluminum alloy, calculation results were compared with experimental results. Accuracy of the modified Johnson–Cook constitutive equation was further proved.
-
A modified Johnson–Cook model of dynamic Tensile behaviors for 7075-T6 aluminum alloy
Journal of Alloys and Compounds, 2015Co-Authors: Ding-ni Zhang, Qian-qian Shangguan, Can-jun Xie, Fu LiuAbstract:Abstract The dynamic mechanical behaviors of 7075-T6 aluminum alloy at various strain rates were measured by dynamic Tensile tests using the electronic universal testing machine, high velocity testing system and split Hopkinson Tensile Bar (SHTB). Stress–strain curves at different rates were obtained. The results show that the strain rate hardening effect of 7075-T6 aluminum alloy is significant. By modifying the strain rate hardening term in the Johnson–Cook constitutive model, a new Johnson–Cook (JC) constitutive model of 7075-T6 aluminum alloy was obtained. The improved Johnson–Cook model matched the experiment results very well. With the Johnson–Cook constitutive model, numerical simulations of Tensile tests at different rates for 7075-T6 aluminum alloy were conducted. According to Tensile loading and stress–strain relation of 7075-T6 aluminum alloy, calculation results were compared with experimental results. Accuracy of the modified Johnson–Cook constitutive equation was further proved.
