|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Effect of high temperature on compression property and deformation recovery of ceramic fiber reinforced silica aerogel composites显示文摘Ceramic fiber reinforced silica aerogel composites are novel insulation materials in the thermal protection field for hypersonic vehicles. Before the aerogel composites are applied in load-bearing structures, it is necessary to investigate their mechanical properties including load-bearing and deformation recovery capabilities. High temperature from service conditions will have important effects on the mechanical properties of thermal protection materials. In this paper, compression tests including loading and unloading stages were conducted for ceramic fiber reinforced silica aerogel composites at room temperature and elevated temperatures(300℃, 600℃ and 900℃). Influences of thermal exposure to high temperature and high temperature service environment on the compression property and deformation recovery were both investigated. Scanning electron microscopy(SEM), Fourier transform infrared spectroscopy(FT-IR) and X-ray diffraction(XRD) were applied to help understand the mechanisms of mechanical property variations. The experimental results show that the compression modulus and strength both increase with the increasing thermal exposure temperature and testing temperature,but the deformation recovery capability decreases. The micro structure changes caused by thermal sintering are considered as the main reason for the property variations.Viscous flow and matter transport due to high temperature resulted in the fusion of aerogel particles. This made the particle skeleton thicker and stronger, which led to higher stiffness and strength of the composites. However, matrix cracks induced by the formation and fracture of larger pores made unrecoverable deformation more serious. In the tests at elevated temperatures,the aggregation of aerogel particles in a fused state got more severe because of the addition of mechanical load. As a result, the degradation of deformation recovery capability became more significant. | LYU ShuangQi YANG XiaoGuang SHI DuoQi QI HongYu JING Xin LI ShaoLin | 2017 | Science China(Technological Sciences)2017，60，11： | 4 |
| 2 | Experimental investigation and numerical modeling for elastoplastic notch-root stress/strain analysis under monotonic loadings显示文摘Experimental investigation and numerical modeling on elasto-plastic notch-root stress/strain distributions under monotonic loadings of both the Ni-based directionally solidified(DS)superalloy and Titanium alloy were carried out simultaneously.For measuring inhomogeneous deformation fields at notch roots,an optical-numerical full-field surface deformation measurement system was developed based on the digital image correlation(DIC)method.The obtained strain distributions were then verified with reasonable accuracy by finite element simulation,where an anisotropic elastic-viscoplastic constitutive model was developed for DS superalloy and a simple isotropic stress-strain relationship was adopted for Titanium alloy.Meanwhile,factors affecting elasto-plastic notch-root stress/strain distributions were systematically investigated numerically,where the emphasis was placed on temperature,loading stress rate,sample shape,anisotropy and notch features.The results show that stress/strain behavior at notch root is significantly affected by the mentioned factors,which are concretely embodied in the distribution of tensile stress/strain,equivalent stress and accumulative equivalent plastic strain. | HUANG Jia SHI DuoQi YANG XiaoGuang PAN Bing SHI Hao | 2014 | Science China(Technological Sciences)2014，57，7： | 3 |
| 3 | Out of phase thermal mechanical fatigue investigation of a directionally solidified superalloy DZ125显示文摘Out of phase(OP) thermal mechanical fatigue(TMF) behavior of a directionally solidified(DS) superalloy DZ125 was experimentally and numerically studied. Two different temperature conditions, which are 500–1000 °C and 400–900 °C, were considered in the present research.Stress and strain responses as well as fatigue life results were presented and discussed. Scanning electron microscope(SEM) and metallographic analysis were used to study the damage mechanism. An oxidation assisted crack initiation and propagation phenomenon were found to explain the shorted life under TMF cycles. In order to characterize the stress and strain deformations under TMF loadings, a modified Chaboche's constitutive model was applied. Additionally, the TMF life of the material was modeled and predicted by Neu–Sehitoglu damage law with high accuracy. | Hu Xiaoan Yang Xiaoguang Shi Duoqi Yu Huichen | 2016 | Chinese Journal of Aeronautics2016，29，1： | 3 |
| 4 | A reduced-order method for parameter identification of a crystal plasticity model considering crystal symmetry显示文摘The focus of this paper is to identify the material parameters of a crystal plasticity model for Ni-base single crystal superalloys.To facilitate the stepwise calibration of the multistage flow rules, further decoupling and simplification are implemented without compromising its simulating capability. Reduced-order kinematics in crystal plasticity, which only comprise scalar components instead of their original tensors, are derived by considering the crystal symmetry and uniaxial loading condition. The relationships between components in elastic and plastic deformation gradient are established by explicitly accounting the control quantities, which is overall load in stress-controlled creep tests or displacement of gauge section in strain-controlled experiments,respectively. In addition, their approximate forms are also given by neglecting both elastic changes in volume and section area. A new objective function based on the shortest distance was introduced to correlate data from the simulations and experiments, and an integrated optimization process without finite element computation was developed into a commercial software package.Parameters in the crystal plasticity model are successfully calibrated by the efficient reduced-order method from the experimental data in such a sequence as: elastic, plastic, primary stage and secondary to tertiary stages creep laws. The multistage weak coupling flow rules can significantly reduce the non-uniqueness of the optimal solution under the circumstance of excessive parameters but insufficient experimental data. Finally, the optimized results with the reduced-order method have been validated by the finite element method. | HAN ShiWei YANG XiaoGuang SHI DuoQi HUANG Jia | 2019 | Science China(Technological Sciences)2019，62，3： | 2 |
| 5 | Improvement on the modeling of rate-dependent plasticity and cyclic hardening by Bodner-Partom model显示文摘 | SHI Duoqi YANG Xiaoguang WANG Yanrong | 2005 | Chinese Journal of Aeronautic2005，18，1： | 1 |
| 6 | Experimental study and numerical modeling of the damage evolution of thermal barrier coating systems under tension显示文摘This study investigated the damage evolution(i.e., formation of vertical cracks, transformation of vertical cracks to interfacial crack and delamination) of thermal barrier coating systems under tension by using experimental and numerical methods.Experimental results revealed that the first transverse crack that was perpendicular to the load direction occurred when the strain of the top coat reached 0.5%. The full-scale strain of the top coat layer obtained by using the Digital Image Correlation technique indicated that surface cracks formed due to the coalescence of micro-cracks. Moreover, the results of the finite element method demonstrated that the vertical cracks initiated from the coating surface and extended through the thickness of the coatings. The density of the surface cracks was used as a damage evolution indicator such that numerical simulation could predict the cracking behaviour under tension loading. The results were consistent with those of the experimental study. | LI ShaoLin YANG HongWei QI HongYu SONG JiaNan YANG XiaoGuang SHI DuoQi | 2018 | Science China(Technological Sciences)2018，61，12： | 1 |
| 7 | Experi mental investigation on mechanical properties of a fiber reinforced silica aerogel composite 显示文摘 | Yang Xiaoguang Sun Yantao Shi Duoqi | 2011 | Materials Science and Engineering A2011，528，1314： | 1 |
| 8 | A modern and robust methodology for modeling anisotropic creep characteristics of Ni-based DS and SC superalloys显示文摘According to more recent work,the Wilshire equations have shown good prediction accuracy in a wide range of materials and stress-temperature conditions,particularly in extrapolation of short term results to long term predictions.In the current paper,this methodology was further developed for modeling anisotropic creep characteristics(i.e.minimum creep strain εmin ,stress rupture life tf and time to a specified strain tε)of four typical Ni-based directionally solidified(DS)and single crystal(SC)superalloys,where a simple orientation factor related to the ultimate tensile strength(UTS)was introduced.The application of these simplistic approaches showed that the anisotropic creep characteristics in a wide range of stress-temperature conditions can be accurately simulated.Meanwhile,during the application of the modified Wilshire equations,break points occurring at the specified stress levels agree well with the transition of creep deformation mechanisms occurring in different stress regions,which provides confidence for using this method. | HUANG Jia SHI DuoQi YANG XiaoGuang | 2014 | Science China(Technological Sciences)2014，57，9： | 1 |
| 9 | Experi-mental investigation on low cycle fatigue and creep-fatigueinteraction of DZ125 in different dwell time at elevatedtemperatures显示文摘 | SHI Duoqi LIU Jinlong YANG Xiaoguang | 2010 | Materials Science and Engineering2010，528，23： | 1 |
| 10 | Experi-mental investigation on both low cycle fatigue and fracturebehavior of DZ125 base metal and the brazed joint at ele-vated temperature显示文摘 | YANG Xiaoguang DONG Chengli SHI Duoqi | 2011 | Materials Science and Engineering2011，528，22： | 1 |
| 11 | Experimental,analytical and numerical investigation on tensile behavior of twisted fiber yarns显示文摘Stitched composite materials are emerging as a promising material due to their high interlaminar strength,combined performance and light weight.The mechanical properties of stitch yarns are very essential for stitched composite structures.In this study,the tensile behaviors of the twisted fiber yarn in stitched composites were investigated experimentally,analytically and numerically.Two kinds of cross-sectional area of twisted yarn are proposed and discussed.The paper presents an intersecting circle model to describe the cross-section of twisted fiber yarns,and a physics-based theoretical model to predict the effective tensile moduli.The numerical models take into account the cross-sectional characteristic and the twist architecture.The investigation shows that:the sum of each fiber area should be used for experimental analysis;and the crosssectional area surrounded by the yarn profile should be used for theoretical predictions and finite element(FE)simulations.The relative errors of the prediction method and the FE simulation are less than 2%and 1%,respectively.The friction between the fibers is derived,and the effect of friction on mechanical properties is discussed.The investigation method will serve as a fundamental component of twisted fiber bundle/yarn analysis. | Xuefeng TENG Duoqi SHI Xin JING Shuangqi LYU Xiaoguang YANG | 2021 | Chinese Journal of Aeronautics2021，34，5： | 1 |
| 12 | An energy-based low-cycle fatigue life evaluation method considering anisotropy of single crystal superalloys显示文摘The crystal orientation significantly affects the low-cycle fatigue (LCF) propertiesof single crystal (SC) superalloys. However, the orientation-dependent LCF life model withprecise mechanisms and strong applicability is still lacking. This investigation aims at establishing an energy-based LCF life evaluation method that could consider the orientation effect. First,the influencing factors of anisotropy were identified through the literature review. Secondly, themultiaxial formula of the Ramberg-Osgood (ReO) equation was established to describe theanisotropic cyclic deformation characteristics. Furthermore, the strain energy density of SC superalloys was determined based on this equation, and the effective strain energy density wasintroduced to account for the effect of orientation. Finally, the energy-based method was validated by its application to several SC superalloys. Results showed that the crystallographicorientation with a lower Young’s modulus usually exhibits better LCF resistance. This phenomenon could be attributed to the different values of strain energy density dissipated in one cycle.The multiaxial ReO relationship could capture the anisotropic cyclic deformation response ofDD6. Compared with the classical methods, the energy-based model is favored by its precisemechanism and strong applicability. And it also exhibited better prediction accuracy. Most datapoints of different crystallographic orientations lay within the 3 error band. | Tianxiao Sui Duoqi Shi Yongsheng Fan Zhenlei Li Xiaoguang Yang | 2022 | Propulsion and Power Research2022，11，2： | 0 |
| 13 | A multi-scale framework for life reduction assessment of turbine blade caused by microstructural degradation显示文摘The prolonged thermal exposure with centrifugal load results in microstructural degradation,which ultimately leads to a reduction in the fatigue and creep resistance of the turbine blades.The present work proposes a multi-scale framework to estimate the life reduction of turbine blades,which combines a microstructural degradation model,a two-phase constitutive model,and a microstructure-dependent fatigue and creep life reduction model.The framework with multi-scale models is validated by a Single Crystal(SC)Ni-based superalloy at the microstructural length-scale and is then applied to calculate the microstructural degradation and the fatigue and creep life reduction of turbine blades under two specific service conditions.The simulation results and quantitative analysis show that the microstructural degradation and fatigue and creep life reduction of the turbine blade are heavily influenced by the variations in the proportion of the intermediate state,namely,the maximum rotor speed status,in the two specific service conditions.The intermediate state accelerates the microstructural degradation and leads to a reduction of the life,especially the effective fatigue life reserve due to the higher temperature and rotational speed than that of the 93%maximum rotor speed status marked as the reference state.The proposed multi-scale framework provides a capable approach to analyze the reduction of the fatigue and creep life for turbine blade induced by microstructural degradation,which can assist to determine a reasonable Time Between Overhaul(TBO)of the engine. | Xiaoguang YANG Menglei WANG Duoqi SHI Zhenlei LI Yongsheng FAN | 2024 | Chinese Journal of Aeronautics2024，37，1： | 0 |
| 14 | A physically-based representative stress methodology for predicting stress rupture life of Ni-based DS superalloy显示文摘Smooth and three types of U-shape single-edge notched plate specimens adopted to experimentally investigate stress rupture behavior of Ni-based Directionally Solidified(DS)superalloy at 850℃ exhibit notch weakening effect and multi-source cracking initiation near the notch root.However,stress rupture behavior of smooth and V-shape notched round bars at 1040℃ revealed by Li et al indicates notch strengthening effect and creep micro-holes originating mostly from the central portion.A combined creep-viscoplastic constitutive model is employed to analyze the distribution of stress,strain and stress Triaxial Factor(TF)near the notch root.The different stress distribution and creep restraint between asymmetric notched plate specimens and symmetric notched round bars are the main reasons for the corresponding failure mechanism.Meanwhile,a good qualitative relationship exists between TF value and stress rupture life of notched specimen.Especially,the area with maximum TF value(TF_(max))is highly consistent with creep damage initiation region.Hence,based on the distribution characteristics of the initial tensile loading,a representative stress method independent of time-changing creep load at the location of TF_(max) is conducted for life prediction.The predicted results of both smooth and notched plate specimens and round bars agrees well with the experimental results. | Jia HUANG Zhenzhuo HE Shuangqi LYU Xiaoguang YANG Duoqi SHI Yantao SUN Yongzhao LYU Zhizhong FU Guolei MIAO Jianan SONG | 2023 | Chinese Journal of Aeronautics2023，36，6： | 0 |
| 15 | An orientation-dependent creep life evaluation method for nickel-based single crystal superalloys显示文摘This paper aims to propose a creep life evaluation method considering the effect of crystallographic orientation.First,the maximum Schmid factor of{111}〈112〉and the corresponding lattice rotation angle were introduced to form an“orientation factor”.Then the equivalent stress was calculated by multiplying this factor and the nominal stress.Latterly,the Larson-Miller Parameter(LMP)method was adopted as the rupture life evaluation criteria,in which the input variable was the equivalent stress instead of the nominal stress.All the predictions showed high accuracy when the proposed method was applied to Mar-M247,SC7-14,CMSX-2,Alloy454,CMSX-4 and DD6.Finally,the applicable temperature ranges of the orientation-dependent method(using equivalent stress)and the traditional LMP method(using nominal stress)were discussed.The results show that only the Orientation-Dependent(OD)method is reliable at intermediate temperatures(760–850°C)because the orientation has significant effect on the stress rupture life,while the influence of orientation is considerably reduced at high temperatures.Both methods provide precise predictions in this situation,and the LMP method should be favored since it is much easier to implement. | Duoqi SHI Tianxiao SUI Zhenlei LI Xiaoguang YANG | 2022 | Chinese Journal of Aeronautics2022，35，1： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员