The ice impact can cause a severe damage to an aircraft’s exposed structure,thus,requiring its prevention.The numerical simulation represents an effective method to overcome this challenge.The establishment of the ic...The ice impact can cause a severe damage to an aircraft’s exposed structure,thus,requiring its prevention.The numerical simulation represents an effective method to overcome this challenge.The establishment of the ice material model is critical.However,ice is not a common structural material and exhibits an extremely complex material behavior.The material models of ice reported so far are not able to accurately simulate the ice behavior at high strain rates.This study proposes a novel high-precision macro-phenomenological elastic fracture model based on the brittle behavior of ice at high strain rates.The developed model has been compared with five reported models by using the smoothed particle hydrodynamics method so as to simulate the ice-impact process with respect to the impact speeds and ice shapes.The important metrics and phenomena(impact force history,deformation and fragmentation of the ice projectile and deflection of the target)were compared with the experimental data reported in the literature.The findings obtained from the developed model are observed to be most consistent with the experimental data,which demonstrates that the model represents the basic physics and phenomena governing the ice impact at high strain rates.The developed model includes a relatively fewer number of material parameters.Further,the used parameters have a clear physical meaning and can be directly obtained through experiments.Moreover,no adjustment of any material parameter is needed,and the consumption duration is also acceptable.These advantages indicate that the developed model is suitable for simulating the iceimpact process and can be applied for the anti-ice impact design in aviation.展开更多
As a model bee metal, tantalum and its alloys have wide applications in defense-related fields. The KHL (Khan, Huang, Liang, 1999) model and the constitutive model proposed by Nemat-Nasser et al (Nemat-Nasser and K...As a model bee metal, tantalum and its alloys have wide applications in defense-related fields. The KHL (Khan, Huang, Liang, 1999) model and the constitutive model proposed by Nemat-Nasser et al (Nemat-Nasser and Kapoor, 2001) for tantalum and its alloys were analyzed and compared with each other. A set of published data recorded during elastic-plastic deformations of tantalum, tantalum alloy containing tungsten of 2.5% (Ta-2.5W), over a wide range of strains, strain rates, and temperatures were used to correlate the two models. Overall, it can be concluded that KHL model correlates much better with the data than the model used by Nemat-Nasser et al.展开更多
基金supported by the National Science and Technology Major Project,China(No.J2019-I-0013-0013)。
文摘The ice impact can cause a severe damage to an aircraft’s exposed structure,thus,requiring its prevention.The numerical simulation represents an effective method to overcome this challenge.The establishment of the ice material model is critical.However,ice is not a common structural material and exhibits an extremely complex material behavior.The material models of ice reported so far are not able to accurately simulate the ice behavior at high strain rates.This study proposes a novel high-precision macro-phenomenological elastic fracture model based on the brittle behavior of ice at high strain rates.The developed model has been compared with five reported models by using the smoothed particle hydrodynamics method so as to simulate the ice-impact process with respect to the impact speeds and ice shapes.The important metrics and phenomena(impact force history,deformation and fragmentation of the ice projectile and deflection of the target)were compared with the experimental data reported in the literature.The findings obtained from the developed model are observed to be most consistent with the experimental data,which demonstrates that the model represents the basic physics and phenomena governing the ice impact at high strain rates.The developed model includes a relatively fewer number of material parameters.Further,the used parameters have a clear physical meaning and can be directly obtained through experiments.Moreover,no adjustment of any material parameter is needed,and the consumption duration is also acceptable.These advantages indicate that the developed model is suitable for simulating the iceimpact process and can be applied for the anti-ice impact design in aviation.
文摘As a model bee metal, tantalum and its alloys have wide applications in defense-related fields. The KHL (Khan, Huang, Liang, 1999) model and the constitutive model proposed by Nemat-Nasser et al (Nemat-Nasser and Kapoor, 2001) for tantalum and its alloys were analyzed and compared with each other. A set of published data recorded during elastic-plastic deformations of tantalum, tantalum alloy containing tungsten of 2.5% (Ta-2.5W), over a wide range of strains, strain rates, and temperatures were used to correlate the two models. Overall, it can be concluded that KHL model correlates much better with the data than the model used by Nemat-Nasser et al.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.1212221l,11772275,U19A20110,and 51825504)Research Fund of State Key Laboratory of Traction Power(Grant No.2019TPL-T1l).