Mansour Rafeeyan

• Associate Professor
• Faculty Member at Yazd University

Maneuverability is one of the most important performance characteristics of submarines. Before constructing a designed AUV, the hydrodynamic model can be used to determine its inherent motion behavior. Standard submarine motion equations (SSME) are the most widely used hydrodynamic model in which more than 100 coefficients must be estimated. These...

Rotating machines are recognized as crucial assets for most of factories. Their internal design and working conditions inevitably subject them to vibration, which in most cases is undesirable. One of these machines is vertical motor-pump and its vibration reduction using dynamical vibration absorber is the goal of this investigation. Experiments ar...

Vibration analysis is one of the most practical methods for monitoring and troubleshooting of rotating equipment. In this research, vibration analysis and support vector machine algorithm were used for monitoring and troubleshooting Alstom locomotive blowers. First, vibration data were collected from the blowers and the received signals were catego...

Constant speed is a necessary condition for inspection pigs because they have enough time to get data from their installed sensors. Keeping the pig in constant speed is very important especially in gas pipelines because of high velocity of the fluid. This paper suggests a simple method based on sliding mode control, which is a time-domain robust co...

Periodic piezoelectric beams have been used for broadband vibration energy harvesting in recent years. In this paper, a periodic folded piezoelectric beam (PFPB) is introduced. The PFPB has special features that distinguish it from other periodic piezoelectric beams. The Adomian decomposition method (ADM) is used to calculate the first two band gap...

In this study, a new periodic beam model is introduced. This beam consists of the concentrated rigid masses and tapered beam elements with linearly variable width. The theoretical equations are derived by employing the Euler-Bernoulli beam and the Bloch–Floquet theorem and then solved using the generalized differential quadrature rule method to cal...

The problem of power loss in rotating machinery subjected to the angular misalignment and unbalancing faults are of great importance in relevant industries. Therefore, in this study, evaluation of the power loss and bearing forces of a typical coupling-disk-shaft system with angular misalignment and unbalancing faults is conducted using a novel app...

A bimorph piezoelectric beam with periodically variable cross-sections is used for the vibration energy harvesting. The effects of two geometrical parameters on the first band gap of this periodic beam are investigated by the generalized differential quadrature rule (GDQR) method. The GDQR method is also used to calculate the forced vibration respo...

In this paper, a robust optimal fuzzy controller based on the Pulse Width Modulation (PWM) technique is proposed to control a laboratory parallel robot using inexpensive on/off solenoid valves. The controller coefficients are determined using Modified Cuckoo Optimization Algorithm. The objective function of this method is considered such that the r...

In this article, based on a series of laboratory experiments, a new cubic energy-based damage index is introduced for identifying damage locations using acceleration measurements of strengthen-free and GFRP-strengthened reinforced concrete beams having different boundary conditions. For this purpose, wavelet-packet energy has been chosen as feature...

The present study aims to implement an approach for trajectory control of a 3-RPR parallel manipulator over a path with obstacles in the workspace. For this purpose, using the spline curves approach and based on the cuckoo optimization algorithm, a smooth reference trajectory with minimum length is generated in the workspace to avoid robot collisio...

In this paper a non-diagonal regulator, based on the QFT method, is synthesized for an uncertain MIMO plant whose output and control signals are subjected to time-domain constraints. This procedure includes the design of a non-diagonal pre-controller based on a new simple approach, followed by the sequential design of a diagonal QFT controller. We...

This paper deals with the dynamic analysis and simulation of Pipeline Inspection Gage (PIG) through the two and three dimensional gas pipelines. Continuity, momentum and the state equations are employed to achieve the gas flow parameters like density, velocity and pressure along the pipeline since the dynamic behavior of the pig depends on the flow...

ماشین¬های صنعتی از قبیل موتور پمپ¬ها، سهم بسیار بزرگی در دنیای صنعت امروزی دارند و نگهداری و تعمیرات آن¬ها، ضرورتی است که همواره بدان توجه شده است. هدف از این پژوهش که با همکاری دانشکده مکانیک دانشگاه یزد صورت گرفته است، برقراری ارتباط بین عیوب داخلی موتور پمپ¬ها و یکی از ابزار¬های نگهداری و تعمیرات پیشگویانه یعنی سیگنال¬های ارتعاشی اندازه¬گیری شده...

Recent investigations have demonstrated the ability of semiactive devices to reduce the structural vibration. In this paper, a new device called the semiactive damper actuator (SADA) is introduced, which reduces the vibration response of structures during earthquakes. Numerical simulations are carried out to study the effects and advantages of SADA...

حمل و نقل ريلي، سهم بزرگي در حمل و نقل دنياي كنوني دارد و استفاده از روش¬های نوین نگهداری و تعمیرات در آن، ضرورتي اجتناب¬ناپذیر است. زیرا این روش¬ها تا کنون جوابگویی ارزنده¬ای در تشخیص سریع و به موقع عیوب تجهیزات داشته¬اند. این پژوهش که با همکاری مرکز تعمیرات لکوموتیو بافق صورت گرفته، با انگیزه¬ی یافتن پارامترهای جدید (علاوه بر فاکتور تاجی) در تشخی...

This paper evaluates a new and simple controller design method based on QFT (quantitative feedback theory) for a two-link manipulator whose first link is rigid and the second is flexible. A piezoelectric patch is attached to the surface of the flexible link for vibration suppression of it. This system is modeled as a nonlinear multi-input multi-out...

حمل و نقل ريلي، سهم بزرگي در حمل و نقل دنياي كنوني دارد و استفاده از روش های نوین نگهداری و تعمیرات در آن، ضرورتي اجتناب ناپذیر است. زیرا این روش ها تاکنون جوابگویی ارزنده ای در تشخیص سریع و به موقع عیوب تجهیزات داشته اند. با این انگیزه و با هدف ایجاد نگاهی جدید به روش های سنتی تشخیص عیوب در ماشین ها، این تحقیق تلاش می کند تا برای یکی از روش های سن...

نظارت بر کارکرد ماشین‌آلات در همه‌ی شاخه‌های صنعت به‌سرعت در حال گسترش است. هدف از نظارت بر ماشین‌آلات و پایش وضعیت، مشخص نمودن عیوب دستگاه‌های در حال کار می‌باشد. روش‌های مختلفی در زمینه پایش وضعیت وجود دارد که یکی از مهم‌ترین آن‌ها بررسی ارتعاشات ماشین‌ها است. عیوب ایجاد شده در ماشین باعث تغییر سیگنال‌های ارتعاشی می‌شوند. برای بررسی وسعت و پیشرفت...

تجزیه و تحلیل ارتعاشات ماشین آلات دوار می تواند وضعیت عیوب بالقوه مانند نابالانسی، ناهمراستایی، محور خم، ترک محور، لقی بیرینگ ، مالش روتور، لقی، غلغله و شلاق روغن و سایر عیوب را نشان دهد. تشخیص عیوب روتور در سال های اخیر دارای اهمیت شده است. مقالات بسیاری چاپ شده که با عیوب تکی کار کرده اند، اما معمولاً، بیش از یک عیب می تواند در روتور رخ دهد. این...

In this paper, a non contact method for measuring instantaneous tension in a wire, based on equations of lateral vibrations of wires, is introduced. The lateral vibration of the string is measured using an eddy current transducer and is sent to a computer. This signal is then imported to a suitable software for fast Fourier transform (FFT) processi...

Cracks in concrete beams have a major influence on their responses. Crack existence in concrete can initiates debonding in a strengthened RC beam. In this article, an experimental study has been performed for damage detection and localization in RC beams and FRP-strengthened RC beams. For this purpose, some specimens are examined using piezoelectri...

To provide an efficient inspection of pipeline, pigging operations must be executed at a constant speed. This paper presents an efficient and simple method based on Quantitative Feedback Theory (QFT), which is a well-known robust controller scheme, for speed control of a pig with bypass flow in a liquid pipeline. This classical-type controller comm...

The derivation and solution of the two and three dimensional dynamic equations for a small pipeline inspection gauge (Pig) through a liquid pipeline is the main aim of this work. These equations can be used for synthesis of speed controller of a pig by using a bypass port in Pig. Momentum and energy equations are employed to study the influence of...

در اين تحقيق، پاسخ ارتعاشي تير بتن آرمه¬ي ساده و نيز تير بتن آرمه مقاوم¬سازي شده با GFRP به روش آزمايشگاهي مورد بررسي قرار گرفته است. با استفاده از بررسي تغييرات انرژي سيگنال با تبديل پاکت-موجک و استفاده از شاخص آسيب و شاخص¬هاي ارزيابي انرژي، پاسخ تيرهاي سالم با پاسخ آن¬ها پس از آسيب در درجات آزادي مختلف، مقايسه شده¬اند و مکان و شدت آسيب به خوبي تخ...

Misalignment and unbalanc of rotating machinery. Several methods for modeling and detecting these faults rare cases concentrated on the energy loss rate due to these faults based on equations of motion for a system with misalignment and unbalance loss calculation and the governing equations are solved cases of with and without the faults and also f...

In this paper, active vibration control of a simply supported rectangular plate made from functionally graded materials (FGM) with fuzzy logic control (FLC) is investigated and compared to the results obtained with the application of PID control. According to the importance of vibration reduction of plates as a major element of industrial and aeros...

تاكنون پردازش هاي سيگنال مختلفي براي عيب يابي جعبه دنده ها ارائه شده اند، در اين مقاله هدف يافتن روش مناسب براي تشخيص هر عيب با استفاده از آناليز سيگنال ارتعاشي است. به همين دليل از جعبه ي دنده ي تك سرعته در دو حالت سالم و معيوب (دندانه ي سايش يافته، نيمه شكسته و تمام شكسته) و در هر حالت در دو وضعيت خشك و روغنكاري شده ، داده برداري و با روش هاي مخت...

This paper presents a new and simple controller design method based on QFT (quantitative feedback theory) for a two-link manipulator whose first link is rigid and the second is flexible. A piezoelectric patch is attached to the surface of the flexible link for vibration suppression of it. This system is modeled as a nonlinear multi-input multi-outp...

This paper deals with the dynamics of small pipeline inspection gauges (pigs) in space pipelines. First, the differential equations for dynamic analysis of the small pig, whose length is short, are developed. The flow field can significantly influence the pig's trajectory. In this research, the effect of the flow field on the pig's trajectory was i...

Active control vibrations of an arbitrary point of a simply supported rectangular plate is presented in this paper. The governing differential equation of plate with attached piezoelectric sensor/actuator patches, whose effects of mass and stiffness are included by the local functions, is solved at first. The response of the plate is computed using...

In this research, active control of vibrations of a simply supported rectangular plate is investigated by a new method. At first, differential equation of motion of a plate with piezoelectric patches is developed by means of classical plate theory in order to apply in this method, and a local function is used for applying the mass and stiffness eff...

This paper presents a method for calculating the PIG motion in pipelines. The PIG speed may control through the amount of bypass flow across its body. The dynamic behavior of the PIG depends on the pressure difference across its body and the bypass flow through it. The system dynamics includes: dynamics of driving gas flow behind the PIG, dynamics...

This paper reports an analytical study of the contact pressure between an elastic garment and some parts of the human body whose geometries are cylindrical and conical, which is based on contact mechanics. The results of this model are compared with a numerical simulation using the finite element method as well as an experimental approach. This mod...

A QFT-type frequency-domain controller design technique is presented for multiple input-multiple ouput (MIMO) nonlinear systems with significant structured (parametric) uncertainty. Hard time-domain constraints are imposed on the outputs and control inputs in response to step disturbances. The control design method is based on replacing the nonline...

This paper deals with the dynamics of small pipeline inspection gauges (pigs) in space pipelines. First, the differential equations for dynamic analysis of the small pig, whose length is short, are developed. The flow field can significantly influence the pig's trajectory. In this research, the effect of the flow field on the pig's trajectory was i...