Research on residual stress in SiCf reinforced titanium matrix composites

Haitao Qu,Hongliang Hou,Bing Zhao,Song Lin 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.17 No.2

This study aimed to theoretical calculate the thermal residual stress in continuous SiC fiber reinforced titanium matrix composites. The analytical solution of residual stress field distribution was obtained by using coaxial cylinder model, and the numerical solution was obtained by using finite element model (FEM). Both of the above models were compared and the thermal residual stress was analyzed in the axial, hoop, radial direction. The results indicated that both the two models were feasible to theoretical calculate the thermal residual stress in continuous SiC fiber reinforced titanium matrix composites, because the deviations between the theoretical calculation results and the test results were less than 8%. In the titanium matrix composites, along with the increment of the SiC fiber volume fraction, the longitudinal property was improved, while the equivalent residual stress was not significantly changed, keeping the intensity around 600 MPa. There was a pronounced reduction of the radial residual stress in the titanium matrix composites when there was carbon coating on the surface of the SiC fiber, because carbon coating could effectively reduce the coefficient of thermal expansion mismatch between the fiber and the titanium matrix, meanwhile, the consumption of carbon coating could protect SiC fibers effectively, so as to ensure the high-performance of the composites. The support of design and optimization of composites was provided though theoretical calculation and analysis of residual stress.

Novel fuzzy direct torque control based on constructed functional transformed grey model

Zhao, Wei,Li, Zhizhong,Xu, Jiheng,Zhang, Haitao,Yuan, Yuan The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.6

To reduce the ripple of the magnetic flux and torque of motors and the reduce the hysteresis in motor speed control, an improved grey model predictive fuzzy direct torque control (DTC) method based on function transformation is proposed. First, a function transformation is used to transform the sampled sequences to nonnegative values. This overcomes the disadvantages caused by fluctuant and random sampling of the motor torque and stator flux linkage. Second, an equal dimensional new information model is used to keep the dimensions unchanged, which reduces the time to predict the motor parameters through the model. Moreover, the voltage space vector plane is divided into six sectors, which simplifies the fuzzy control system rules. Simulation results show that the proposed fuzzy direct torque control based on the improved grey model method reduces the influence of hysteresis on the control system, decreases the motor flux chain and torque ripple, improves the response speed of the torque and rotational speed, reduces overshoot, achieves good effects in terms of anti-interference capability and dynamic response, and improves the real-time performance and accuracy of the fuzzy control system.

Fabrication of nanoarchitectured TiO₂(B)@C/rGO electrode for 4 V quasi-solid-state nanohybrid supercapacitors

Zhao, Yongfeng,Zhang, Haitao,Liu, Ao,Jiao, Yuzhi,Shim, Jae-Jin,Zhang, Suojiang Elsevier 2017 ELECTROCHIMICA ACTA Vol.258 No.-

<P><B>Abstract</B></P> <P>Novel TiO<SUB>2</SUB>(B)@C/rGO nanoarchitectures are fabricated by combining hydrothermal treatment, ions exchange, and topological phase transformation as well as carbon modification. Asymmetric hybrid Li-ion nanohybrids supercapacitors with high energy and power densities are constructed by combining hybridized anode, which can supply both pseudo capacitance from TiO<SUB>2</SUB>(B) and electrochemical double layer capacitance (EDLC) from nanocarbons (graphene nanosheets and amorphous carbon layer), and activated carbon (AC) as EDLC type cathode. The high power density is realized readily via both the modification of nanocarbons, which not only improve the electric conductivity but introduce extra Faradic capacitance, and the employment of high-voltage formulated ionic liquids electrolyte as well as ionogel polymer separator. Such a balanceable and complementary design between electrode and electrolyte allow rapid ion and electron transport in ionic liquid-based electrolyte and hybridized electrodes. The maximum energy and power density of 59.4 W h/kg and 17.3 kW/kg can be readily realized at 40 <SUP>°</SUP>C on account of the special characteristic of ionic liquids. These results clearly demonstrate that high performance nanohybrid supercapacitors can be actualized through the subtle combination of nanohybridized electrodes and high voltage formulated ionic-liquid/lithium-salt electrolytes, which make them promising power-type energy storage devices for hybrid electric vehicles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High specific capacitive TiO<SUB>2</SUB>(B)@C/rGO nanoarchitetures were successfully synthesized. </LI> <LI> Complete utilization of Faradic and non-Faradic capacitance of nanohybrids was realized by using formulated electrolyte. </LI> <LI> 4 V operating potential was actualized with the presence of ionogel polymer separator. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

State-of-charge Estimation for Lithium-ion Batteries Using a Multi-state Closed-loop Observer

Zhao, Yulan,Yun, Haitao,Liu, Shude,Jiao, Huirong,Wang, Chengzhen The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.5

Lithium-ion batteries are widely used in hybrid and pure electric vehicles. State-of-charge (SOC) estimation is a fundamental issue in vehicle power train control and battery management systems. This study proposes a novel model-based SOC estimation method that applies closed-loop state observer theory and a comprehensive battery model. The state-space model of lithium-ion battery is developed based on a three-order resistor-capacitor equivalent circuit model. The least square algorithm is used to identify model parameters. A multi-state closed-loop state observer is designed to predict the open-circuit voltage (OCV) of a battery based on the battery state-space model. Battery SOC can then be estimated based on the corresponding relationship between battery OCV and SOC. Finally, practical driving tests that use two types of typical driving cycle are performed to verify the proposed SOC estimation method. Test results prove that the proposed estimation method is reasonably accurate and exhibits accuracy in estimating SOC within 2% under different driving cycles.

Hierarchical Architectures of PMMA/MWNT-NH2 Particles: A Material for Enhanced Volatile Organic Compound Sensing Performance

Haitao Li,Yang Sun,최형진,Siqin Zhao 한국고분자학회 2018 Macromolecular Research Vol.26 No.9

Hierarchical architectures of poly(methyl methacrylate) (PMMA)/aminofunctionalized multi-walled carbon nanotube (MWNT-NH2) particles were prepared, in which the electrical conductive network was constructed on the surface of PMMA microspheres. The morphology, composition, and electrical conductivity of the particles were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and four-probe electrical conductivity measurement. The PMMA/MWNT-NH2 transducers were exposed to each ethanol, water, toluene, and chloroform for volatile organic compounds (VOCs) sensing detection. The particles showed excellent sensitivity, good reversibility, and a strong response compared to the raw MWNTs and MWNT-NH2. This was attributed not only to the formation of a charge transmission path on the particle surface, but also to the interaction between the vapor molecules and functionalized MWNTs. The enhanced sensing performance of the PMMA/MWNT-NH2 particles suggests that it is a good candidate for the preparation of electronic noses for disease diagnostics and VOCs detection.

Indoor and Outdoor Scene Classification Method Based on Fourier Transform

Zhijie Zhao,Haitao Wang,Xuesong Jin,Huadong Sun,Qian Wu 보안공학연구지원센터 2014 International Journal of Hybrid Information Techno Vol.7 No.5

State-of-charge Estimation for Lithium-ion Batteries Using a Multi-state Closed-loop Observer

Yulan Zhao,Haitao Yun,Shude Liu,Huirong Jiao,Chengzhen Wang 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.5

Lithium-ion batteries are widely used in hybrid and pure electric vehicles. State-of-charge (SOC) estimation is a fundamental issue in vehicle power train control and battery management systems. This study proposes a novel model-based SOC estimation method that applies closed-loop state observer theory and a comprehensive battery model. The state-space model of lithium-ion battery is developed based on a three-order resistor?capacitor equivalent circuit model. The least square algorithm is used to identify model parameters. A multi-state closed-loop state observer is designed to predict the open-circuit voltage (OCV) of a battery based on the battery state-space model. Battery SOC can then be estimated based on the corresponding relationship between battery OCV and SOC. Finally, practical driving tests that use two types of typical driving cycle are performed to verify the proposed SOC estimation method. Test results prove that the proposed estimation method is reasonably accurate and exhibits accuracy in estimating SOC within 2% under different driving cycles.

Enzyme-assisted extraction of astaxanthin from Haematococcus pluvialis and its stability and antioxidant activity

Xiaoyan Zhao,Xiaowei Zhang,Hongkai Liu,Haitao Zhu,Yunping Zhu 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.6

The release of bioactive pigments could bepotentially improved by enzyme degradation of plant cellwall polysaccharides. In this study, the objective was toevaluate enzyme type (cellulase and pectinase), pH values,hydrolysis temperature and time on the release of astaxanthinfrom Haematococcus pluvialis (H. pluvialis). Theresults showed that pre-treated H. pluvialis with enzymescould improve the separation yield of astaxanthin. Pectinaserelease rate of astaxanthin from H. pluvialis wassignificantly higher than cellulase (p\0.05), and enzymehydrolysis time was also shorter. The stability study ofastaxanthin oleoresin and microcapsule during storage atdifferent temperature, oxygen and illumination was foundthat the degradation rate of astaxanthin rose with increasingtemperature and illumination time, and the retention inoxygen environment decreased. The stability of astaxanthinmicrocapsules was better than astaxanthin oleoresin.

Grinding Damage of BK7 using Copper-Resin Bond Coarse-Grained Diamond Wheel

Qingliang Zhao,Junyun Chen,Haitao Huang,Xiaoyan Fang 한국정밀공학회 2011 International Journal of Precision Engineering and Vol. No.

Coarse-grained wheels can realize high efficient grinding of optical glass. However, the serious surface and subsurface damage will be inevitably introduced by the coarse-grained wheels. In this paper, the grinding damage of a copper-resin bond coarse-grained diamond wheel with grain size of 150μm was investigated on optical glass BK7. The wheel was first properly trued with a metal bond diamond wheel, then pre-dressing for the wheel and grinding experiments are carried out on a precision grinder assisted with electrolytic in process dressing (ELID) method. The surface roughness (Ra) of ground surface was measured using an atomic force microscope (AFM) and the surface topography were imaged by a white light interferometer (WLI) and the AFM. The subsurface damage level of ground surface was evaluated by means of both MRF spot method and taper polishing-etching method, in term of the biggest depth of subsurface damage, distribution of micro defects beneath the ground surface, the cluster depth of subsurface damage, relationship between subsurface damage (SSD)and PV surface roughness (SR), propagating distance and pattern of cracks beneath the ground surface. Experimental results indicate that a well conditioned copper-resin bond coarse-grained diamond wheel on a precision grinder can generate good surface quality of Ra less than 50nm and good subsurface integrity with SSD depth less than 3.5μm for optical glass BK7.

Research and Optimization of Lateral Compressive Performance of the 3-D Printed Beetle Elytron Plate

Caiqi Zhao,Tengteng Zheng,Lijie Shang,Haitao Lan,Shuo Yang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.8

In this paper, two types of beetle elytron plates (end-trabecular beetle elytron plate (EBEP) and middle-trabecular beetle elytron plate (MBEP)) and honeycomb plate (HP) were manufactured by 3-D printed and applied to large-span spatial structure. The lateral compressive performance of the 3-D printed beetle elytron plate was investigated by lateral compression bearing capacity test and numerical analysis. The influence of number of cylinders, ratio of the radius of the cylinder to the side length of the hexagonal honeycomb core (ratio of radius-length), thickness of core layer and configuration of beetle elytron plate on the lateral compressive performance of the beetle elytron plates were studied and the optimization method for lateral compressive performance of the beetle elytron plates was proposed. The result shows that the lateral compression bearing capacity of EBEP is greater than that of MBEP, and both are greater than of HP. The lateral compression bearing capacity of the beetle elytron plate with six cylinders is about 25% higher than that of the HP without cylinders. The lateral compression bearing capacity of beetle elytron plate can be improved by increasing the thickness of plates. The results of the study will promote the application of beetle elytron plates in large-span spatial structures.