The Study of Hydroelastic Behavior of Submerged Slender Bodies Considering Sloshing in Tanks

, M.Sc. Thesis Sharif University of Technology Mobasserfar, Yasin (Author) ; Haddadpour, Hassan (Supervisor)

Abstract

In the present work, dynamic behavior of submerged slender bodies under external hydrodynamic forces with internal sloshing tanks is studied. The main application of this thesis is in submarines. For this purpose slender body theory is used for hydrodyanamics of body and unsteady hydrodynamics is used for the vehicle control fins. In submarines there are some water tanks that control the buoyancy, so that sloshing can be importatnt. An equivalent mechanical model is developed for simulating the dynamics of sloshing tanks. Assuming that a submarine is a slender body, elastic deformation of submarine body can affect dynamics of the whole system. Elastic behavior of the main body is simulated...

Skew-normal log-volatility model of road surface profile

, Article Mechanical Systems and Signal Processing ; Volume 177 , 2022 ; 08883270 (ISSN) Mobasserfar, Y ; Adibnazari, S ; Shariyat, M ; Sharif University of Technology

Academic Press 2022

Abstract

Road roughness-induced vibrations are the main source of fatigue damage accumulation in vehicles. Hence, road surface profile modeling and simulation are of high importance when it comes to vehicle fatigue damage assessment. This research focuses on uncovering the statistical distributions that describe the characteristics of road loads that affect fatigue damage accumulation. Particle filtering is deployed to estimate the log-volatility of the road surface profile by assuming a random walk behavior for the hidden log-volatility. The skew-normal distribution with three parameters is fitted to the estimated log-volatility. The inferred parameters are used for synthesizing artificial road...

A size-dependent generalized thermoelasticity theory for thermoelastic damping in vibrations of nanobeam resonators

, Article International Journal of Structural Stability and Dynamics ; Volume 23, Issue 12 , 2023 ; 02194554 (ISSN) Jalil, A.T ; Saleh, Z. M ; Imran, A. F ; Yasin, Y ; Ruhaima, A. A. K ; Gatea, M. A ; Esmaeili, S ; Sharif University of Technology

World Scientific 2023

Abstract

Thermoelastic damping (TED) has been discerned as a definite source of intrinsic energy loss in miniaturized mechanical elements. The size-dependent structural and thermal behavior of these small-sized structures has been proven through experimental observations. As a first attempt, this article exploits nonlocal strain gradient theory (NSGT) and nonlocal dual-phase-lag (NDPL) heat conduction model simultaneously to acquire a mathematical formulation and analytical solution for TED in nanobeams that can accommodate size effect into both structural and heat transfer fields. For this purpose, the coupled equations of motion and heat conduction are firstly extracted via NSGT and NDPL model....

Effect of pesticides on erythrocytes of indigenous fish Labeo rohita

, Article Journal of King Saud University - Science ; Volume 33, Issue 7 , 2021 ; 10183647 (ISSN) Bano, N ; Nadeem, A ; Maalik, S ; Mushtaq, S ; Iqbal, N ; Khan, A. K ; Shabbir, A ; Imran, M ; Niaz, S ; Yasin, M ; Qayyum, M. A ; Ahmad, B ; Skalicky, M ; Alharbi, S. A ; Alfarraj, S ; Sharif University of Technology

Elsevier B.V 2021

Abstract

Single cell gel electrophoresis was used to observe the effect of bifenthrin and chlorpyrifos on Labeo rohita. The present work was planned to study the genotoxic effect of pesticide mixture on the major indian carp, L. rohita at sub-lethal concentration 33% LC50. First of all, 96-hr LC50 was determined for L. rohita, then fish was given sub-lethal environment for 70 days. Erythrocytes from blood were taken after each fortnight for the assessment of time dependent DNA damage (% damage), aggregate tail length of comets and genomic destruction. There was increase in damage up to 56 days and after that a slight decrease was observed in next fourteen days. After statistical analysis, it was...