Stability analysis for design improvement of bio-inspired flapping wings by energy method

, Article Aerospace Science and Technology ; Volume 111 , 2021 ; 12709638 (ISSN) Kamankesh, Z ; Banazadeh, A ; Sharif University of Technology

Elsevier Masson s.r.l 2021

Abstract

This study attempts to reach a broad understanding of the stability properties of nonlinear time-periodic flapping wing structures. Two bio-system models, Hummingbird (6DOF) and Hawkmoth (3DOF) are developed for this purpose. Initial analysis on the Hummingbird model, which is based on the Floquet theory, kinetic energy integration, and phase portrait technique, indicates lack of stability in hover flight. Kinetic energy integration is carried out on the extended model of the Hawkmoth to find the domain of attraction and increase the level of stability by varying the design parameters. Here, the hinge location of the wing, flapping amplitude, flapping frequency, and mean angle of attack are...

Stability Analysis of Nonlinear Periodically Time-Varying Dynamic Systems By Studying Typical Insect-Like Flapping Wing

, M.Sc. Thesis Sharif University of Technology Kamankesh, Zahra (Author) ; Banazadeh, Afshin (Supervisor)

Abstract

Designing Nonautonomous periodic systems such as helicopters, multirotors, monocopters or the dynamics of flapping wings requires stability analysis and careful examination in order to identify and determine their dynamic behaviour. In practice, analysis and design are interdependent and the design of nonlinear control systems involves an iterative process. To know the importance of identifying and to accurately implement methods to analyse this kind of systems in the field of aerospace, the flapping wing can be a good example. The issue of stability and the control of the flapping wings have not yet had a clear solution, and the current research including controller design based on linear...

Seismic Vulnerability Assessment of Masonry Infilled RC Frames with Different Infill Configuration and Opening

, M.Sc. Thesis Sharif University of Technology Kamankesh, Yones (Author) ; Bakhshi, Ali (Supervisor)

Abstract

Reinforced concrete buildings with open ground storey are vulnerable to accumulate of large lateral displacement at the ground story. This is due to drastic reduction in the relative stiffness of the ground story compared to the upper stories, a phenomenon known as soft storey effect. Furthermore inevitable Existence of Opening in masonry infill and increasing it’s area reduces both the lateral strength and stiffness of the fully infilled RC frames so when percentage of the central opening is very high, the behaviour of the infilled frame approaches the bare frame. It is a perception about open ground storey buildings that openings in the upper stories infilled frame offset the soft storey...

Frequency domain identification of a tapered beam embedded by piezoelectric layer

, Article 2016 International Conference on Advanced Mechatronic Systems, ICAMechS 2016, 30 November 2016 through 3 December 2016 ; 2017 , Pages 312-317 ; 23250682 (ISSN); 9781509053469 (ISBN) Banazadeh, A ; Ahranjani, F. F ; Kamankesh, Z ; Sharif University of Technology

IEEE Computer Society 2017

Abstract

This study is conducted aiming to identify the dynamics of a tapered beam, embedded by piezoelectric layer. Narrowing the tip of the beam equipped with piezoelectric patches leads to optimize the output power after excitation by the frequency sweep input. An accelerometer is installed on the beam base, which measures the acceleration that is applied to the system. Piezoelectric sensors also measure the generated voltage. The experimental test data is handled through CIFER software, using Fourier transform and Bode plot in the frequency domain, to obtain appropriate transfer functions. MATLAB is used for nonlinear simulation and validation of discrete transfer functions by a set of data that...

Effect of strain path change on mechanical properties and final microstructure of Cu-Al2O3 in equal channel angular pressing

, Article Materials Science and Technology (United Kingdom) ; Volume 29, Issue 2 , 2013 , Pages 210-218 ; 02670836 (ISSN) Monshat, H ; Serajzadeh, S ; Akhgar, J. M ; Kamankesh, A ; Sharif University of Technology

2013

Abstract

In the present work, the process of equal channel angular pressing of dispersion strengthened Cu-1̇1 wt-%Al2O3 containing nanometric alumina particles was investigated by means of mathematical modelling and experimental testing. Through the modelling, deformation parameters such as hydrostatic pressure distribution and strain field were determined, and the effect of deformation path on these parameters was estimated. Equal channel angular pressing as well as mechanical and microstructural evaluations were also conducted to assess mechanical properties, grain structure and void volume fraction after deformation in different routes. The results indicate that distributions of plastic strain and...

Liquid-liquid equilibrium (LLE) data for ternary mixtures of {aliphatic+p-xylene+[EMpy][ESO 4]} at T=313.15K

, Article Fluid Phase Equilibria ; Volume 332 , 2012 , Pages 48-54 ; 03783812 (ISSN) Kamankesh, A ; Vossoughi, M ; Shamloo, A ; Mirkhani, S. A ; Akbari, J ; Sharif University of Technology

Elsevier 2012

Abstract

Liquid-liquid equilibrium (LLE) data for the ternary systems (heptane. +. p-xylene. +. 1-ethyl-3-methylpyridinium ethylsulfate) and (n-octane. +. p-xylene. +. 1-ethyl-3-methylpyridinium ethylsulfate) were measured at . T=. 313.15. K and atmospheric pressure. The selectivity and aromatic distribution coefficients, calculated from the equilibrium data, were used to determine if this ionic liquid can be used as a potential extracting solvent for the separation of p-xylene from heptane and n-octane. The consistency of tie-line data was ascertained by applying the Othmer-Tobias and Hand equations

Evaluation of Process Partitioning of Enzyme in Polymer-Salt Aqueous Two-PHase Systems

, M.Sc. Thesis Sharif University of Technology Kamankesh, Amin (Author) ; Alamzadeh, Iran (Supervisor) ; Vossoughi, Manouchehr (Supervisor) ; Pazuki, Gholamreza (Supervisor)

Abstract

In this research, the amount of partitioning Invertase to be evaluated in nine systems, these systems contain Peg 2000,Peg 4000 & Peg 6000 with three different salt.In first, Binodal curve for nine systems to be drown by cloudy point method, then five point be selected in each system such as sample feed. Invertase in every systems to be solved in constant weight fraction. The analysis of every phasesto be achieved by Merchuk method. For correlation data of this method to be used by Othmer-Tobias method and then using equation Mrchvk ensure the accuracy of phase analysis , analysis of the results obtained with the UV method was studied.Accuracy of UV analysis was studied by using lattice...