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Research on influence of typical microstructure characteristics of Ni base single crystal on creep rupture and deformation analysis of turbo blade

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航空动力学报 2011年第5期26卷 1148-1158页

作者： CAO Juan WANG Yan-rong SHI duo-qi School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing 100191 China

Considering the influence of typical microstructure characteristics on creep performance,a series of UM-F single crystal alloys which had similar element components but different microstructures were used to analyze the relationship between creep life and microstructure characteristics of Ni base single *** main factors were proposed:misfit,volume fraction of precipitate and maximum matrix channel *** Microstate parameter Ymicro was established to estimate the deformation state of the *** linear relationship between the initial value of microstate parameter Y0 and creep life under a certain temperature/load was *** analyzing the high temperature region of turbo blade using the material parameters of DD 3,the creep deformation and the life prediction of the critical points of blade were obtained and the result closed to the test.

关键词：《航空动力学报》期刊摘要编辑部

A physically based methodology for predicting anisotropic creep properties of Ni-based superalloys

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Rare Metals 2016年第8期35卷 606-614页

作者： Jia Huang duo-qi Shi Xiao-Guang Yang School of Energy and Power Engineering Beihang University

This paper is focused on developing suitable methodology for predicting creep characteristics （i.e., the minimum creep strain rate, stress rupture life and time to a specified creep strain） of typical Ni-based directionally solidified （DS） and single-crystal （SC） superalloys. A modem method with high accuracy on simulating wide ranging creep properties was fully validated by a sufficient amount of experimental data, which was then developed to model anisotropic creep characteristics by introducing a simple orientation factor defined by the ultimate tensile strength （UTS）. Physical confidence on this methodology is provided by the well-predicted transitions of creep defor- mation mechanisms. Meanwhile, this method was further adopted to innovatively evaluate the creep properties of different materials from a relative perspective.

关键词： Wilshire equations Anisotropic creepproperties Ni-based superalloy Prediction methodologyCreep mechanism

Research on consensus of multi-agent systems with and without input saturation constraints

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Journal of Systems Engineering and Electronics 2021年第4期32卷 947-955页

作者： qi duo HU Junhua LIANG Xiaolong ZHANG Jiaqiang ZHANG Zhihao Air Traffic Control and Navigation College Air Force Engineering UniversityXi’an 710051China Shaanxi Province Lab.of Meta-Synthesis for Electronic&Information System Xi’an 710051China Aeronautical Engineering College Air Force Engineering UniversityXi’an 710038China

In recent years,with the continuous development of multi-agent technology represented by unmanned aerial vehicle(UAV)swarm,consensus control has become a hot spot in academic *** this paper,we put forward a discrete-time consensus protocol and obtain the necessary and sufficient conditions for the second-order consensus of the second-order multi-agent system with a fixed structure under the condition of no saturation *** theoretical derivation verifies that the two eigenvalues of the Laplacian of the communication network matrix and the sampling period have an important effect on achieving *** we construct and verify sufficient conditions to achieve consensus under the condition of input saturation *** results show that consensus can be achieved if velocity,position gain,and sampling period satisfy a set of inequalities related to the eigenvalues of the Laplacian ***,the accuracy and validity of the theoretical results are proved by numerical simulations.

关键词： multi-agent system consensus control input constraint distributed control

Microstructural evolution and restoration of creep property for a damaged K403 alloy after rejuvenation heat treatments

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Rare Metals 2021年第7期40卷 1865-1871页

作者： Liang Wang Xiao-Guang Yang Hong-Yu qi duo-qi Shi Shao-Lin Li School of Energy and Power Engineering Beihang UniversityBeijing 100191China Beijing Key Laboratory of Aero-Engine Structure and Strength Beijing 100191China

Rejuvenation heat treatments can restore the microstructures and mechanical properties of the degraded turbine blades in gas turbine *** we analyze the effects of rejuvenation heat treatments on the microstructural characteristics and mechanical properties of damaged and undamaged specimens of a Ni-based superalloy,*** damaged specimens were found to have degraded microstructures and shorter creep lifetime than the undamaged *** rejuvenation heat treatment proved beneficial,especially for specimens exposed to damage for 50 *** addition,the microstructure recovery and creep life were found to depend on the predamage durations of the specimens.A y’-precipitate-based creep lifetime model was established to predict the residual lifetime based on the microstructural information.

关键词： Microstructural evolution Creep property Restoration Rejuvenation heat treatments

Low-cycle fatigue behavior of DZ125 superalloy under prior exposure conditions

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Rare Metals 2023年第6期42卷 2028-2036页

作者： Hong-Yu qi Xiao-Lei Zheng Li-qiang Ma Shao-Lin Li Xiao-Guang Yang duo-qi Shi School of Energy and Power Engineering Beihang UniversityBeijing100191China Collaborative Innovation Center of Advanced Aero-Engine Beijing100191China Shenyang Engine Design and Research Institute Aviation Industry Corporation of ChinaShenyang110015China

Low-cycle fatigue(LCF) behavior of the directionally solidified(DS) nickel-based DZ125 superalloy was studied at elevated temperature(980 ℃).Specimens were,respectively,exposed for 0,2,25,50,and 100 h in *** fatigue life of pre-exposed specimens is lower than that of unexposed *** result is closely associated with fatigue crack initiation and propagation due to oxygen embrittlement and cycle *** fractographic evaluations indicate the fatigue life is closely related to the surface microstructural *** resulting changes in microstructure cause the decrease in the effective area and the increase in actual stress.A methodology based on the continuum damage mechanics is developed to describe the correlation between the residual LCF life and pre-exposed time.

关键词： Nickel-based superalloy Oxidation Prior exposure Low-cycle fatigue Continuum damage mechanics

Constitutive modeling of a directionally solidified nickel-based superalloy DZ125 subjected to thermal mechanical creep fatigue loadings

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Rare Metals 2019年第10期38卷 922-936页

作者： Xiao-An Hu Xiao-Guang Yang duo-qi Shi Hui-Chen Yu Ting-Ting Ren School of Energy and Power Engineering Beihang UniversityBeijing 100191China Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical MaterialsBeijing 100095China Air Force Armament Department China Aviation MuseumBeijing 102211China

A transversely isotropic continuum elasto-viscoplasticity model,which was developed from Chaboche’s unified constitutive model,was formulated to capture the thermal mechanical creep fatigue deformation behavior of a directionally solidified nickel-based superalloy.A fourthorder tensor was introduced to model material *** order to model the tertiary creep behavior,the Kachanov damage evolution equation was coupled into the stress *** on the test results of uniaxial tensile,fatigue,and creep loadings at isothermal temperature conditions,the material parameters are *** mechanical fatigue(TMF) and creep-fatigue interaction test results were used to verify the robustness of the ***,strain-temperature-dependent stress-strain responses under TMF loadings were analyzed using the present *** strain-controlled conditions,both of the stress ranges and mean stresses are strongly influenced by the strain-temperature phases,a key parameter for TMF tests.

关键词： Constitutive Thermal mechanical fatigue Creep Viscoplastic Superalloy

Unified modeling of high temperature deformations of a Ni-based polycrystalline wrought superalloy under tension-compression, cyclic, creep and creep-fatigue loadings

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Science China(Technological Sciences) 2015年第2期58卷 248-257页

作者： HUANG Jia SHI duo qi YANG Xiao Guang YU Hui Chen DONG Cheng Li School of Energy and Power Engineering Beihang University Beijing Institute of Aeronautical Materials

The complex deformation behaviors under tension-compression, cyclic, creep and creep-fatigue loadings of a nickel-base polycrystalline wrought superalloy at 650℃ and 700℃ were experimentally investigated. To uniformly simulate the complex deformation behaviors, the modified viscoplastic constitutive model combined with both the Kachanov damage evolution equation and the Ohno-Wang modification was formulated on the basis of the Chaboche theory. The simulated results on ten-sion-compression behavior, cyclic viscoplastic and creep deformations showed comprehensive predicting ability. With the obtained material parameters, the deformations in creep-fatigue interaction under three dwell types were simulated and the capability of the modified model was further verified with good accuracy.

关键词： superalloy constitutive relation fatigue creep creep-fatigue interaction

Research on Water-Exit and Take-off Process for Morphing Unmanned Submersible Aerial Vehicle

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China Ocean Engineering 2017年第2期31卷 202-209页

作者： HU Jun-hua XU Bao-wei FENG Jin-fu qi duo YANG Jian WANG Cong Engineering College of Aeronautics and Astronautics Air Force Engineering University Flying Instructor Training Base Air Force Aviation University

This paper presents a theoretic implementation method of Morphing Unmanned Submersible Aerial Vehicle （MUSAV）, which can both submerge in the water and fly in the air. Two different shapes are put forward so that the vehicle can suit both submergence and flight, considering the tremendous differences between hydrodynamic configuration and aerodynamic configuration of a vehicle. The transition of the two shapes can be achieved by using morphing technology. The water-to-air process, including water-exit, morphing, take-off and steady flight, is analyzed. The hydrodynamic and aerodynamic model of the vehicle exiting the water surface obliquely and then taking off into the air has been founded. The control strategy after morphing is analyzed and the control method is given. Numerical method is used to validate the motion model of the water-exit process. Results of simulations show the validity of the proposed model and the feasibility of MUSAV in theory.

关键词： Morphing Unmanned Submersible Aerial Vehicle (MUSAV) water-to-air process dynamic model flight control

Fatigue response,fracture characteristic and life modeling of a near-alpha titanium alloy under typical cyclic loadings in service

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Rare Metals 2016年第9期35卷 676-685页

作者： Jia Huang Yin-Yin Luo Peng-Tao Zhao duo-qi Shi Xiao-Guang Yang Hui-Chen Yu School of Energy and Power Engineering Beihang UniversityBeijing 100191China Shanghai Electric Power Equipment Co. Ltd.Shanghai Steam Turbine FactoryShanghai 200240China Beijing Institute of Aeronautical Materials Beijing 100095China

Experimental investigations on the fatigue behavior of a near-alpha titanium alloy under typical cyclic loadings were carried out to simulate the service loading states applied on the engine *** axial stress-controlled tension–tension low-cycle fatigue（LCF） tests were carried out over a range of maximum stresses and stress *** rotary bending tests were conducted using a step-loading procedure to reveal the high-cycle fatigue（HCF） limit *** cyclic softening effect is observed in this material,and the strain ratcheting occurs obviously at the maximum LCF loading of 900 *** LCF resistance is found to be dependent on both the maximum loading and the stress *** HCF limit stresses for 1 9 107 and 1 9 106 cycles are determined as405.7 and 457.6 MPa,*** macroscopic fatigue fracture mode and the failure features on fracture surfaces were analyzed by scanning electron microscope（SEM）.

关键词： Titanium alloy High-cycle fatigue Lowcycle fatigue Fracture analysis Ratcheting