The manuscript discusses issues related to the use of mathematical modeling to substantiate the reliability and safety of the Superjet-100 aircraft during the emergency landing.The problem of the passenger airplane ai...The manuscript discusses issues related to the use of mathematical modeling to substantiate the reliability and safety of the Superjet-100 aircraft during the emergency landing.The problem of the passenger airplane airframe dynamic deformation in the landing with partially removed and released the landing gear under given initial conditions of touching the runway of the airfield.Confirmation of the adequacy and reliability of modeling and the accuracy of numerical results are considered.展开更多
A computing technology of the numerical simulations based on Abaqus code is presented in this paper for complex analysis of the uniaxial compressed stiffened composite panel,having local impact damage.The technology a...A computing technology of the numerical simulations based on Abaqus code is presented in this paper for complex analysis of the uniaxial compressed stiffened composite panel,having local impact damage.The technology allows simulating both dynamic deformations of the panel subjected to local impact and followed up by an axial static compression.A reliability of the developed computing technology is confirmed by comparison and closeness of the obtained numerical results and experimental data.Discrepancy of values obtained by the simulation from the corresponding experimental data is 8%for maximum contact force between the panel and impactor,7%for crack length on the opposite to the impact side of the panel and 10%for ultimate force,when the initially damaged panel is in compression.Also,the acceptable qualitative similarity of the modeled fracture mechanism and the shape to that observed in the experiments is observed.展开更多
The present paper discusses issues related to dynamic deformation and failure of the jet engine case impacted by released blade of rotating rotor.It is shown that due to a local area of deformation of the jet engine c...The present paper discusses issues related to dynamic deformation and failure of the jet engine case impacted by released blade of rotating rotor.It is shown that due to a local area of deformation of the jet engine case impacted by the released blade acceptable failure criterion for the case can be obtained on the base of model tests and corresponding numerical simulations.The equation of motion based on the variation principle of balance of virtual powers of work.The plasticity models of the materials are based on the von Mises yield surface with associated flow rule and isotropic hardening low depends on the strain rate.Numerical solutions of the problem are implemented by the finite element method and explicit scheme of numerical integration in time,realized in the code LOGOS.The uncoupled ductile fracture model is applied with the equivalent plastic strain as failure criterion.Validity of computer simulations is supported by proximity of numerical and experimental data for the depth of cutting of the targets at the impact sides and perforation and perforation time of the targets.Analysis of the principal strains and equivalent plastic strains as well as stress triaxiality parameters during the deformation process up to the failure of the targets is also presented.It is shown that destruction of the plane model of the jet engine case is initiated on the impact side when the equivalent plastic strain normalized by the elongation reaches the levelε_(pl1)^(f)=2.5 with triaxial compression and perforation of the plate takes place ifε_(pl2)^(f)=1.2 on the opposite side of the target plate with biaxial tension.展开更多
Propagation of low cycle fatigue cracks in main parts of an aviation gas turbine engine can cause sudden engine destruction during operationwith catastrophic consequences.Accurate prediction of an engine lowcycle fati...Propagation of low cycle fatigue cracks in main parts of an aviation gas turbine engine can cause sudden engine destruction during operationwith catastrophic consequences.Accurate prediction of an engine lowcycle fatigue durability can be accessed using finite element simulations.Main aspects of the applied approach for low cycle fatigue stable crack propagation finite element simulations in 3D specification for main parts of an aviation gas turbine engine are described in the article.These include applied formulation and procedure,descriptions of applied models and assumptions,parameters of generated grids,some results of grid convergence studies and simulation results for turbine discs.The significance of some aspects for solution accuracy such as along crack front grid resolution is demonstrated.Advancements to the applied approach are proposed which include solution under-relaxation preventing instability when large crack propagation steps are used and circular correction improving crack path prediction accuracy for bodies of revolution.The improvements result in the overall simulation accuracy increase and effort decrease up to 50%.展开更多
文摘The manuscript discusses issues related to the use of mathematical modeling to substantiate the reliability and safety of the Superjet-100 aircraft during the emergency landing.The problem of the passenger airplane airframe dynamic deformation in the landing with partially removed and released the landing gear under given initial conditions of touching the runway of the airfield.Confirmation of the adequacy and reliability of modeling and the accuracy of numerical results are considered.
文摘A computing technology of the numerical simulations based on Abaqus code is presented in this paper for complex analysis of the uniaxial compressed stiffened composite panel,having local impact damage.The technology allows simulating both dynamic deformations of the panel subjected to local impact and followed up by an axial static compression.A reliability of the developed computing technology is confirmed by comparison and closeness of the obtained numerical results and experimental data.Discrepancy of values obtained by the simulation from the corresponding experimental data is 8%for maximum contact force between the panel and impactor,7%for crack length on the opposite to the impact side of the panel and 10%for ultimate force,when the initially damaged panel is in compression.Also,the acceptable qualitative similarity of the modeled fracture mechanism and the shape to that observed in the experiments is observed.
文摘The present paper discusses issues related to dynamic deformation and failure of the jet engine case impacted by released blade of rotating rotor.It is shown that due to a local area of deformation of the jet engine case impacted by the released blade acceptable failure criterion for the case can be obtained on the base of model tests and corresponding numerical simulations.The equation of motion based on the variation principle of balance of virtual powers of work.The plasticity models of the materials are based on the von Mises yield surface with associated flow rule and isotropic hardening low depends on the strain rate.Numerical solutions of the problem are implemented by the finite element method and explicit scheme of numerical integration in time,realized in the code LOGOS.The uncoupled ductile fracture model is applied with the equivalent plastic strain as failure criterion.Validity of computer simulations is supported by proximity of numerical and experimental data for the depth of cutting of the targets at the impact sides and perforation and perforation time of the targets.Analysis of the principal strains and equivalent plastic strains as well as stress triaxiality parameters during the deformation process up to the failure of the targets is also presented.It is shown that destruction of the plane model of the jet engine case is initiated on the impact side when the equivalent plastic strain normalized by the elongation reaches the levelε_(pl1)^(f)=2.5 with triaxial compression and perforation of the plate takes place ifε_(pl2)^(f)=1.2 on the opposite side of the target plate with biaxial tension.
基金sponsored by Sarov Engineering Center(www.saec.ru)supported by the UECKlimov。
文摘Propagation of low cycle fatigue cracks in main parts of an aviation gas turbine engine can cause sudden engine destruction during operationwith catastrophic consequences.Accurate prediction of an engine lowcycle fatigue durability can be accessed using finite element simulations.Main aspects of the applied approach for low cycle fatigue stable crack propagation finite element simulations in 3D specification for main parts of an aviation gas turbine engine are described in the article.These include applied formulation and procedure,descriptions of applied models and assumptions,parameters of generated grids,some results of grid convergence studies and simulation results for turbine discs.The significance of some aspects for solution accuracy such as along crack front grid resolution is demonstrated.Advancements to the applied approach are proposed which include solution under-relaxation preventing instability when large crack propagation steps are used and circular correction improving crack path prediction accuracy for bodies of revolution.The improvements result in the overall simulation accuracy increase and effort decrease up to 50%.
