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Mass and performance optimization of an airplane wing leading edge structure against bird strike using Taguchi-based grey relational analysis

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Chinese Journal of Aeronautics 2016年第4期29卷 934-944页

作者： Hassan Pahange Mohammad hossein Abolbashari Department of Mechanical Engineering Ferdowsi University of Mashhad Department of Mechanical Engineering Lean Production Engineering Research Center Ferdowsi University of Mashhad

Collisions between birds and aircraft are one of the most dangerous threats to flight safety. In this study, smoothed particles hydrodynamics(SPH) method is used for simulating the bird strike to an airplane wing leading edge structure. In order to verify the model, first, experiment of bird strike to a flat aluminum plate is simulated, and then bird impact on an airplane wing leading edge structure is investigated. After that, considering dimensions of wing internal structural components like ribs, skin and spar as design variables, we try to minimize structural mass and wing skin deformation simultaneously. To do this, bird strike simulations to 18 different wing structures are made based on Taguchi’s L18 factorial design of experiment. Then grey relational analysis is used to minimize structural mass and wing skin deformation due to the bird strike. The analysis of variance(ANOVA) is also applied and it is concluded that the most significant parameter for the performance of wing structure against impact is the skin thickness. Finally, a validation simulation is conducted under the optimal condition to show the improvement of performance of the wing structure.

关键词： Bird strike Grey relational analysis Multi-objective optimization Smooth particle hydrody namics(SPH) Wing leading edge structure

On the finite horizon Nash equilibrium solution in the differential game approach to formation control

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Journal of Systems Engineering and Electronics 2019年第6期30卷 1233-1242页

作者： JOND hossein barghi NABIYEV Vasif Department of Computer Engineering Karadeniz Technical University

The solvability of the coupled Riccati differential equations appearing in the differential game approach to the formation control problem is vital to the finite horizon Nash equilibrium *** equations(if solvable)can be solved numerically by using the terminal value and the backward *** investigate the solvability and solution of these equations the formation control problem as the differential game is replaced by a discrete-time dynamic *** main contributions of this paper are as ***,the existence of Nash equilibrium controls for the discretetime formation control problem is ***,a backward iteration approximate solution to the coupled Riccati differential equations in the continuous-time differential game is *** illustrative example is given to justify the models and solution.

关键词： formation control differential game dynamic game Nash equilibrium coupled Riccati equations.

Theoretical study of failure in composite pressure vessels subjected to low-velocity impact and internal pressure

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Frontiers of Structural and Civil Engineering 2020年第6期14卷 1349-1358页

作者： Roham RAFIEE hossein RASHEDI Shiva REZAEE Composites Research Laboratory Faculty o f New Science&TechnologiesUniversity o f TehranTehran ***Iran

A theoretical solution is aimed to be developed in this research for predicting the failure in internally pressurized composite pressure vessels exposed to low-velocity *** in-plane and out-of-plane failure modes are taken into account simultaneously and thus all components of the stress and strain fields are *** this purpose,layer-wise theory is employed in a composite cylinder under internal pressure and low-velocity *** stress/strain components are fed into appropriate failure criteria for investigating the occurrence of *** case of experiencing any in-plane failure mode,the evolution of damage is modeled using progressive damage modeling in the context of continuum damage ***,mechanical properties of failed ply are degraded and stress analysis is performed on the updated status of the *** the event of delamination occurrence,the solution is *** obtained results are validated with available experimental observations in open *** is observed that the sequence of in-plane failure and delamination varies by increasing the impact energy.

关键词： composite pressure vessel low-velocity impact failure theoretical solution progressive damage modeling

Construction of a PVC based 15-crown-5 electrochemical sensor for Ag(Ⅰ) cation

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Chinese Chemical Letters 2014年第5期25卷 809-814页

作者： Fereshteh Karimian Gholam hossein Rounaghi Mohammad hossein Arbab-Zavar Department of Chemistry Faculty of SciencesFerdowsi University of Mashhad

The macrocyclic ligand,15-crown-5,was used as an ionophore for fabrication of a polyvinyl chloride（PVC） based membrane sensor for Ag（Ⅰ） *** construction of the Ag（Ⅰ） cation selective electrode the best response characteristics were obtained using the composition： 15-crown-5/PVC/o-nitrophenyloctylether（NPOE）/sodium tetraphenyl borate（NaTPB） in the percentage ratio of 5.6/30/60.5/3.9（w/w/w/w）.The electrochemical sensor shows a linear dynamic range 1.0 10 7–1.0 10 1mol/L and a Nernstian slope of 58.9 0.5 mV/decade with a detection limit of 8.09 10 8mol/L for Ag（Ⅰ） *** has a fast response time of 〈10 s and can be used for at least 8 weeks without any considerable divergences in its potential *** was successfully used as an indicator electrode in potentiometric titration of Ag（Ⅰ）cation with I and Cl anions and also for the determination of this metal cation in radiology waste water.

关键词： 15-Crown-5 Electrochemical sensor Potentiometry Ag(I)

Improving pulsed laser weldability of duplex stainless steel to 5456 aluminum alloy via friction stir process reinforcing of aluminum by BNi-2 brazing alloy

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Transactions of Nonferrous Metals Society of China 2019年第7期29卷 1401-1412页

作者： hossein ESMAILY Ali HABIBOLAHZADEH Mohammad TAJALLY Faculty of Materials and Metallurgical Engineering Semnan University

Effects of laser pulse distance and reinforcing of 5456 aluminum alloy were investigated on laser weldability of Al alloy to duplex stainless steel (DSS) plates. The aluminum alloy plate was reinforced by nickel-base BNi-2 brazing powder via friction stir processing. The DSS plates were laser welded to the Al5456/BNi-2 composite and also to the Al5456 alloy plates. The welding zones were studied by scanning electron microscopy, X-ray diffractometry, micro-hardness and shear tests. The weld interface layer became thinner from 23 to 5 μm, as the laser pulse distance was increased from 0.2 to 0.5 mm. Reinforcing of the Al alloy modified the phases at interface layer from Al-Fe intermetallic compounds (IMCs) in the DSS/Al alloy weld, to Al-Ni-Fe IMCs in the DSS/Al composite one, since more nickel was injected in the weld pool by BNi-2 reinforcements. This led to a remarkable reduction in crack tendency of the welds and decreased the hardness of the interface layer from ~950 HV to ~600 HV. Shear strengths of the DSS/Al composite welds were significantly increased by ~150%, from 46 to 114 MPa, in comparison to the DSS/Al alloy ones.

关键词： duplex stainless steel (DSS) Al5456 aluminum alloy BNi-2 brazing alloy friction stir processing pulsed laser welding

Design of on-board calibration methods for a digital sun sensor based on Levenberg–Marquardt algorithm and Kalman filters

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Chinese Journal of Aeronautics 2020年第1期33卷 339-351页

作者： Ali RAHDAN hossein BOLANDI Mostafa ABEDI Department of Electrical Engineering Iran University of Science&TechnologyTehran ***Iran Department of Electrical Engineering Shahid Beheshti UniversityTehran ***Iran

Digital sun sensor is one of the most important sensors used in the Attitude Determination System(ADS)of the *** to the harsh environmental conditions that exist in the space,various distortions may occur in the sun sensor optical system that lead to the reduced accuracy of this ***,it is necessary to recalibrate the optical parameters of the aforementioned *** this purpose,first a novel attitude independent error model is proposed for the SS-411 sun sensor that includes the central point of the CCD array,installation error,filter thickness and sensor ***,the mutual interfaces between the sensor parameters are considered in the developed *** order to extract the sensor parameters,a nonlinear optimization technique called the Levenberg–Marquardt is applied to the developed model as a batch *** addition,the Extended Kalman Filter(EKF)and the Unscented Kalman Filter(UKF)have been utilized as sequential *** will be shown that by considering a worst case of variation amount for sensor parameters,an accuracy improvement of about 17°is achieved by the developed calibration *** between the developed algorithms represents that UKF has higher accuracy,shorter time convergence but higher computational load.

关键词： Digital sun sensor Extended Kalman filter Levenberg–Marquardt On-board calibration Unscented Kalman filter

Thermal stress distribution around a thermally-insulated polygonal cutout in graphite/epoxy composite laminates under heat flux

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Journal of Central South University 2021年第11期28卷 3418-3433页

作者： Mohammad hossein baYATI CHALESHTARI Hadi KHORAMISHAD School of Mechanical Engineering Iran University of Science and TechnologyNarmakTehran 16846Iran

In this study,the effect of influencing parameters on the stress distribution around a polygonal cutout within a laminated composite under uniform heat flux was analytically *** analytical method was developed based on the classical laminated plate theory and two-dimensional thermo-elastic method.A mapping function was employed to extend the solution of a perforated symmetric laminate with a circular cutout to the solution of polygonal *** effect of significant parameters such as the cutout angular position,bluntness and aspect ratio,the heat flux angle and the laminate stacking sequence in symmetric composite laminate containing triangular,square and pentagonal cutouts was *** Neumann boundary condition was used at the edges of the thermally insulated polygonal *** laminate was made of graphite/epoxy(AS/3501) material with two different stacking sequences of [30/45]sand[30/0/-30]_(s).The analytical solutions were well validated against finite element results.

关键词： analytical solution thermal stress analysis polygonal cutout complex variable method polymeric composite

A New Evaluation Criterion for Optimizing the Mechanical Properties of Toughened Polypropylene/Silica Nanocomposites

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Chinese Journal of Polymer Science 2020年第8期38卷 877-887,I0008页

作者： hossein Pourrahmani Mona Golparvar Mohammad Fasihi Group of Energy Materials (E)cole Polytechnique Fédérale de LausanneSion 1951Switzerland School of Chemical Petroleum and Gas EngineeringIran University of Science and TechnologyTehran 16846-13114Iran School of Mechanical Engineering Braunschweig university of technologyBraunschweig 38106Germany

This study aims to experiment with the mechanical properties of polypropylene(PP)/thermoplastic elastomer/nano-silica/compatibilizer nanocomposite using the melt mixing *** addition of polyolefin elastomers has proved to be an approachable solution for low impact strength of PP,while it would also reduce the Young's modulus and tensile *** is why reinforcement would be applied to this combination to enhance the elastic *** mechanical properties of the prepared composites were devised to train an artificial neural network to predict these properties of the system in 6256 unknown ***,the sensitivity analysis was performed and the share of each input parameter on the respective output values was ***,a novel parameter called nanocomposite evaluation criterion(NEC)is introduced to analyze the suitability of the nanocomposites considering the mechanical ***,the formulation with optimal mechanical properties of toughness,elongation at break,tensile strength,Young's modulus,and impact strength was obtained.

关键词： Nanocomposite Polypropylene(PP) Silica Artificial neural networks Nanocomposite evaluation criterion(NEC) Sensitivity analysis

Enhanced microstructural and mechanical properties of Stellite/WC nanocomposite on Inconel 718 deposited through vibration-assisted laser cladding

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International Journal of Minerals,Metallurgy and Materials 2022年第2期29卷 327-334页

作者： hossein hosseini-Tayeb Seyed Mahdi Rafiaei Daneshpajoohan Pishro Higher Education Institute IsfahanIran Department of Materials Science and Engineering Golpayegan University of TechnologyGolpayeganIsfahanIran

Stellite-21/WC nanopowders were deposited on Inconel through vibration-assisted laser cladding with different laser *** and scanning electron microscopy,hardness measurements,and wear characterizations were employed to understand the microstructural and mechanical behaviors of the *** showed that varying the cooling rate exerted remarkable effects on the microstructure of the as-cladded ***,increasing the laser power from 150 W to 250 W increased the heat input and the *** was affected by the scanning rate and powder feeding rate at a high laser power of 250 *** WC nanoparticles were added as reinforcement,the dilution magnitude intensified while the hardness value increased from HV 350 to HV *** wear characterizations indicated that the composites containing 3 wt%WC nanoparticles possessed the highest wear resistance.

关键词： Stellite WC nanoparticles mechanical properties laser cladding