Propeller Shaft Research Articles

Frequency Based Damage Detection and Localization of Propeller Shaft of a Ship Using Experimental Modal Analysis

: The whole ship is dependent on the propeller shaft for its movement, the vibrations produced from the shaft destabilizes the whole ship and may lead to accidents. With this objective in mind, in this paper, we describe a methodology to detect and locate the crack present in the intermediate simply supported shaft using experimental modal analysis. In the present work, 304 stainless steel material shaft is taken as the specimen as it is one of the most versatile and widely used steels in the world for making different shafts used in any machinery equipment like ships propeller shaft, engine shafts, motor shafts. Initially, analytical analysis is done on the simply supported shaft then numerical modal analysis using ANSYS 2019 R3 software. Results obtained from the numerical modal analysis are compared with the experimental modal analysis which is done using FFT analyzer. Finally, the first three natural frequencies are used as a tool to detect damage detection and location in the propeller intermediate shaft

Operator based finite element modelling of viscoelastic cracked propeller shaft: a comparative study

The present study focuses on to explore the dynamic analysis of a viscoelastic propeller-shaft system with transverse breathing crack supported by journal bearings. Finite element modelling of the shaft continuum is done considering the Euler-Bernoulli beam theory. Operator based constitutive relationship is applied to incorporate material damping of the rotor and higher-order equations of motion are established. Accurate time-dependent functions are used to formulate cracked element stiffness matrix and augmented to the overall stiffness matrix of the entire system. Eigen analysis is performed after converting the higher-order equation into the first-order form. A Comparative study is demonstrated based on different dynamic parameters like whirl frequency, modal damping factor and stability limit of spin speed. Further, the variation of stability limit of spin speed and natural frequency is also studied based on the parameters such as crack depth and its location along different section of the propeller shaft.

Modification and analysis on fatigue study in universal joint of an automobile vehicle

The main task, especially targets at checking out the standard joint at exceptional operating angles and specific materials in order that the time to failure of the accepted joint may be reduced to a degree. The strength generated inside the engine due to the fact the stop result of combustion of gasoline is converted to wheels through the transmission gadget inside the car. This machine in particular encompasses device container, propeller shafts, tremendous joints and differential gears. The stress shaft imparts torque from the engine (Kamal et al., 2011). The screw ups that added on to the energy shaft is especially because of vibration strain, fatigue, bending pressure or maybe the misalignment of the driveshaft. a majority of those defects especially because of the overloading or even repeated extra time use (Hummel and Chassapis 1998). The main result of all these are the pre-mature failure of the drive shaft at the operation times. For almost all the cases, the failure occurs at the area around the universal joints, as the angle difference and the velocity variations occurs in that area.

Analisis Faktor Kejadian Gangguan Pendengaran di PT Inti Ganda Perdana Plant Karawang Tahun 2019

Study objective - PT. Inti Ganda Perdana Plant Karawang in the process of producing automotive components in the form of rear axle and propeller shaft, of course workers are not free from the dangers of noise. Noise in the work environment ranges from 70 - 104 dB. Besides noise at work, there are other factors that can cause hearing disorders. In a preliminary study it was found that the results of medical check-up as much as 49% of 293 workers suffer from hearing disorders. The purpose of this study is to determine the most associated factors with the incidence of hearing disorders in workers at PT. Inti Ganda Perdana Plant Karawang in 2019. Design and setting – The design of this cross sectional analytic research design. The study population is all workers at PT. Inti Ganda Perdana Plant Karawang with a total sample of 75 respondents. Sampling technique uses Accidental sampling, statistical test using multiple logistic regression analysis. The results of study are the noise intensity (OR = 3,729), age of workers (OR = 2,707) and work period (OR = 7,749). The highest OR is t he work period (OR = 7,749). It means that the workers with work period >10 years will experience hearing disorders of 7,749 times higher than the workers with work period < 10 years after being controlled by variables of noise intensity, age of workers, use of APT and smoking history. Main results - Conclusion of the most related factors to the incidence of hearing disorder is the length of work period. It is recommended that company requires all workers exposed to noise> 81 dB to use ear protection to minimize direct and prolonged exposure to noise from equipment and machinery.Keywords: Hearing Disorder, noise intensity, age of workers, work period.

밸러스트 흘수에서 중형 유조선의 좌현 전타시의 추진축 거동 해석

The propeller shaft of the shafting system has various pattern by the engine power, propeller eccentric thrust and weight, which increases the adverse effect of bearing failure causing load variation on after stern tube bearing. To prevent this, diverse research on the shafting system has been conducted with a focus on optimize the relative slope angle and oil film thickness between the shaft and the support bearing, mainly based on the Rules for the Classification of Steel Ships. However, in order to secure the integrity of the shafting system through a more scrutinized assessment, it is necessary to consider the dynamic condition including the transient condition due to the sudden alteration in the stern wakefield. In this context, for the case ship, this study deals with the effect of propeller shaft behavior at rapid rudder turn portside, which is one of the typical transient conditions at ballast draught. As a result of the analysis, it was confirmed that the estimation of the change of the propulsion shaft behavior due to the transient condition have a different pattern from the interpretation in the quasi-static condition.

A Reverse-Engineering Method for Powertrain Parameters Characterization Applied to a P2 Plug-In Hybrid Electric Vehicle with Automatic Transmission

<div class="section abstract"><div class="htmlview paragraph">Over the next decade, CO2 legislation will be more demanding and the automotive industry has seen in vehicle electrification a possible solution. This has led to an increasing need for advanced powertrain systems and systematic model-based control approaches, along with additional complexity. This represents a serious challenge for all the OEMs. This paper describes a novel reverse engineering methodology developed to estimate relevant powertrain data required for fuel consumption-oriented hybrid electric vehicle (HEV) modelling. The estimated quantities include high-voltage battery internal resistance, electric motor and transmission efficiency, gearshift thresholds, torque converter performance diagrams, engine fuel consumption map and front/rear hydraulic brake torque distribution. This activity provides a list of dedicated experimental tests, to be carried out on road or on a chassis dynamometer, aiming at powertrain characterization thanks to a suitable post-processing algorithm. In this regard, the methodology was applied on a P2 Diesel Plug-in HEV equipped with a 9-speed AT. Voltage and current sensors are used to measure the electrical power exchanged between battery and electric motor; a torque sensor on the propeller shaft measures the total torque coming out from the automatic transmission. The hydraulic pressures in the four brake calipers are measured and CAN data is logged. The results of the testing campaign are then presented and discussed. Functional models of powertrain subsystems are introduced and their parameters estimated using least square method. The good match between models and experimental data proved that the proposed methodology, if properly adapted to the specific layout, is a suitable tool for powertrain parameter estimation.</div></div>

Effect of Transient Condition on Propeller Shaft Movement during Starboard Turning under Ballast Draught Condition for the 50,000 DWT Oil Tanker

Effect of Transient Condition on Propeller Shaft Movement during Starboard Turning under Ballast Draught Condition for the 50,000 DWT Oil Tanker

Crack Identification and Localization In Structural Beams Using Numerical and Experimental Modal Analysis- A Review

This article presents a critical review of recent research done on crack identification and localization in structural beams using numerical and experimental modal analysis. Crack identification and localization in beams are very crucial in various engineering applications such as ship propeller shafts, aircraft wings, gantry cranes, and Turbo machinery blades. It is necessary to identify the damage in time; otherwise, there may be serious consequences like a catastrophic failure of the engineering structures. Experimental modal analysis is used to study the vibration characteristics of structures like natural frequency, damping and mode shapes. The modal parameters like natural frequency and mode shapes of undamaged and damaged beams are different. Based on this reason, structural damage can be detected, especially in beams. From the review of various research papers, it is identified that a lot of the research done on beams with open transverse crack. Crack location is identified by tracking variation in natural frequencies of a healthy and cracked beam

Hybrid Electric Aircraft Switched Model Optimal Control

This work presents the modeling, control design, and simulation of a Cirrus SR20 with a hybrid electric propulsion (HEP) system composed of a combustion engine and battery-supplied electric drive that operates in one of two modes: 1) battery discharging and electric drive propelling, and 2) battery charging and electric drive generating. Given a supervisory-level system model, two optimization control problems are developed. The first finds the elevator deflection and propeller shaft power and speed that minimizes the desired flight profile tracking error. The second manages HEP power flows to provide the desired propeller shaft power while trading off fuel use and battery charge level deviation. The second optimal control problem is a switched problem that requires optimization over discrete and continuous control inputs. The problem is solved using an embedding method that relaxes the discrete valued inputs to continuous values to avoid computational complexity associated with alternate approaches. The resulting model predictive control is demonstrated with simulation of two flight profiles: sawtooth-shaped altitude profile while maintaining constant velocity and an experimental one taken from a production aircraft. Simulations show good profile tracking and appropriate power management. The HEP-equipped aircraft demonstrates a 15.6% fuel savings over the experimental profile; further, the proposed control achieves a 4.3% savings over a rule-based approach under certain conditions.

Energy Analysis of the Propulsion Shaft Fatigue Process in a Rotating Mechanical System Part II Identification Studies – Developing the Fatigue Durability Model of a Drive Shaft

Abstract The article presents a continuation of research carried out concerning identification of energy consequences of mechanical fatigue within a propeller shaft in a rotating mechanical system, while working under conditions of the loss of the required alignment of shaft lines. Experimental research was carried out on a physical model reflecting a full-sized real object: i.e., the propulsion system of the ship. It is proven, by means of an active experiment, that changes in propeller shaft deflection are reflected in the amount of dissipated kinetic energy of masses in rotational motion and the accumulated internal energy in its construction material. Adoption of a high-cycle fatigue syndrome, consisting of diagnostic symptoms determined from the action of the propeller shaft associated with the transformation of mechanical energy into work and heat, as well as with the generation of mechanical vibrations and elastic waves of acoustic emission, is proposed. To assess the diagnostic information quantity brought about by the defined features of propeller shaft fatigue, an experimental research program was developed and implemented, in which two statistical hypotheses are verified: the significance of the impact of the values enforcing the fatigue process, presented in the first part of the article, and the adequacy of the regression equation describing the fatigue durability of the propeller shaft in the energy aspect, constituting the second part of the article. This finally gives us the opportunity, after the appropriate translation of the model test results into full-sized real objects, to develop a methodology to diagnose marine propeller shaft fatigue in operating conditions. The third part of the article is devoted to this issue

IMPROVED ALGORITHM FOR SUPERVISORY CONTROL AND DATA ACQUISITIONOF COMBINED VESSEL’S ENERGY SYSTEM

Main development trends of modern ship power systems have beenanalyzed. The purpose of the paper is the analysis of energy modes and the development of criteria for transitions between different modes of an integrated marine vessel’s power system, providing maximum efficiency in the use of fuel and motor resources of main vessel engines. It is proposed to identify, in addition to the shore-to-ship mode, four main operating modes in the presence of a synchronous machine on a propeller shaft and a converter that ensures an operation of this machine in both motor and generator modes.By dividing the main engine load into four levels –small, medium, nominal and large –an automatic system can accordingly control (or recommend in semi-automatic mode) the switching sequence of power equipment and actuating machines and mechanisms.Usinga few container shipsas an example, it is shown when the ship moves at a low speed, the main engine load becomes so low that it can be provided by diesel generatorsof the ship’s energy system (“Power-Take-Home”mode). This, on the one hand, allows to save fuel, and on the other hand increases the completeness of fuel oil consumption, since diesel generators operate at an optimal load unlike the main engine, the load of which reaches only 10percent. Similarly, in case of medium loading of the main engine, it is recommended to switch to the power supply of ship’s grid from the main engine with the shaft generator (“Power-Take-Off”mode), and if it is necessary to obtain increased power of the propulsion system, the synchronous machine is switched totheengine mode powered by diesel generators (“Power-Take-In”mode). In addition, the ability to switchofthese and mainmodesin emergency situationsquickly increases thevessel’ssurvivability and safety. Based on the analysis, an algorithm for switching between modes is proposed, which can be implemented in Supervisory Control Ad Data Acquisition ofship’s energy systems, in particular, on a physical simulator at the National University “Odessa Maritime Academy”.

Tribological comparison of an optimum single and double slope design of the stern tube bearing, case study for a marine vessel

In the present work, the optimal geometric parameters of a double slope aft stern-tube bearing are determined, for (a) maximizing the ‘effective pressure’ area between the bearing and the propeller shaft, and (b) minimizing the maximum local pressure exerted on the bearing surface. The aft stern-tube bearing design is modeled parametrically, taking into account the elastic shaft geometry. The computational approach used evolves from the solution of the Reynolds differential equation, which yields bearing operational parameters. The system is coupled to a general-purpose optimizer to calculate the optimum geometry based on two objective functions. Optimum designs for single and double slope bearings are calculated, and the performance parameters of these designs are compared for normal and extreme operational conditions.

Theoretical and experimental analysis of an unbalanced and cracked cardan shaft in the vicinity of the critical speed

This paper presents a theoretical and experimental analysis of a coupled lateral and torsional vibrations of two identical rotors interconnected by a flexible Hooke’s joint and modelled as a multibody system with a small misalignment angle. Using energy principle and a Lagrangian transformation, the governing equation of the propeller shaft system is established by considering a nonlinear elastic shaft time-dependent perturbation. To study the sensitivity of the crack for a rotating shaft, the model is enriched by considering the periodical feature of the time-varying stiffness deriving from the crack breathing model. The nonstationary response of a cracked rotor system in the presence of unbalance has been evaluated using orbit patterns and Fast Fourier Transform. The highly oscillated feature of the rotors system is theoretically obtained and experimentally analysed. The analysis demonstrated that the crack parameters in the input shaft tend to inhibit the occurrence of unstable oscillations in lateral deflection, orbit and frequency spectrum of the secondary response. It is also found that the passage of the cracked primary shaft near to an integral multiple of the critical speed leads to the phenomenon of sup-harmonic resonance. Subsequently, the experimental analysis conducted equally indicated that the quantitative relation between the faults and the performance of the transmission is impacted by the time-varying stiffness and is the main cause of the frequency-modulated feature in the Cardan shaft system. Finally, the experimental results were informative for the transient response exploration and comparable to the theoretical findings for validating the proposed twin-rotor model.

SEREP-based reduced model of higher order viscoelastic propeller shaft considering various asymmetries

The material damping of rotors causes instability by introducing tangential force to whirl orbit. Literature shows that the improvement of stability range is achieved using fibre-reinforced composites or layered rotors which are light yet strong and exhibit better damping properties. In this study, a multi-layered viscoelastic propeller shaft mounted on three journal bearings is considered. Higher order finite-element model is developed after utilizing operator-based constitutive relationship, which includes various asymmetries from several sources like gyroscopic effect, internal damping, and journal bearing support. A large number of states of the higher order model, as well as the presence of asymmetry, make the system complicated for post-processing. Modified system equivalent reduction expansion process (SEREP) is applied for model reduction that uses both right and left eigenvectors of the original propeller-shaft system. Different numerical results are compared to test the effectiveness of reduced model. Though SEREP is found in the literature, its application over most realistic and higher order asymmetric system is completely new.

Improving the efficiency and reliability of combined ship propulsions

Purpose. Ensuring high propulsion performance in a wide range of modes by optimizing the control of technological processes of energy use. Ways to improve energy efficiency and reduce the environmental impact of diesel propulsion systems were considered. A Container ship was choose, as example. A ship`s combined type propulsion unit is equipped with a synchronous machine, which is installed in the propeller shaft line and performs the function of a shaft generator. Its use is possible only when the vessel main diesel engine operates with a power above 40% of the nominal. In economy modes and in special conditions of vessel movement with lower power, the efficiency of the working process in the main engine decreases, fuel consumption per unit of power and time, as well as harmful emissions, increases. That is, in the existing composition, the propulsion unit does not meet a modern requirements for efficiency and environmental friendliness, and the practice of its use is not flexible enough. Methodology. To confirm the economic feasibility of modernization and the use of PTH mode, mathematical modeling of electromechanical transients in the "Ship network - vectordriven synchronous motor - load" system was performed. Results. Improving the safety and survivability of the ship (PTH mode) due to the additional propeller independent of the main engine of the electric drive. Reducing fuel consumption and harmful emissions into the environment, which increases the EEIO (Energy Efficiency Operational Index) of the vessel. Originality. The developed version of the modernization of the propulsion installation provides running mode of the vessel in special situations with reduced power by means of using the shaft generator as a motor. To implement this option, the propulsion installation need to be equipped additionally with a hydraulic coupling, which is allow to disconnect the main engine from the propeller shaft and to change over to electrical driving of ship propeller. The advantages of the propeller electric drive as the synchronous machine and frequency converter which is supplied from the ship's electrical network, are analyzed in comparison with the main diesel engine operates with low power. The block diagrams of the electric drive with vector control are given. Practical value. When the vessel is moving at a low speed, switching to PTH mode saves fuel (up to 118 kg / h), and increases the completeness of its combustion, since diesel generators operate at optimal load, unlike the main engine, which in this case is extremely unfavorable for the machine.

Оценка влияния упругих свойств подшипников скольжения дейдвудного устройства судна на значение коэффициента жесткости

The article considers the ship shaft line as a complex dynamic system influencing the operation of the ship. There has been given a diagram of the shaft line with one stern bearing and one remote bearing of the propeller shaft. The shaft line service life depends on the material of the slide bearing of the stern gear (lignum vitae, babbitt, textolite, caprolon, bronze, polyurethanes, rubber). The analysis of the research of static and dynamic calculations of ship shafting has been carried out. The design scheme of the ship shafting on elastic point supports is presented. It has been referred to consider feasibility of the elastic and mechanical properties of stern bearings at the stage of designing a ship shaft line. The method of calculating the transverse vibrations of the shaft line is studied, the purpose of which is to determine the natural frequency. The formula for calculating the lowest natural frequency of bending vibrations is given. The results of experimental studies at the KMV-200 stand based on uneven distribution of loads along the stern bearings are considered. It has been suggested that the greater the wear, the lower the stiffness coefficient. At a certain degree of wear of stern bearings, a resonance phenomenon occurs at the lowest operating frequencies. The value of the stiffness coefficient is studied depending on the modulus of elasticity of the stern bearing material. Static analysis of the ship shaft line was made taking into account the stiffness coefficient of the stern bearing. The universal equation of the curved axis of the beam is used according to the initial parameters method. As it has been found, the greater the deflection at the propeller attachment point, the lower the natural frequency of the transverse vibrations of the shaft line. In calculations it is necessary to take into account the separation of the shaft line from the stern bearing, since it helps to reduce the natural frequency and the appearing resonance during transverse vibrations.

Design and Analysis of Composite Reinforced Steel Propeller Shaft for Improved Strength

Design and Analysis of Composite Reinforced Steel Propeller Shaft for Improved Strength

Static and Modal Analysis of Propeller Shaft of LMV

Static and Modal Analysis of Propeller Shaft of LMV

Effect of Shaft Misalignment on Hypoid Gear Pair Driven Through a Universal Joint

An enhanced hypoid geared rotor system model incorporating a universal joint that connects driveline propeller shaft and pinion shaft is introduced in this study. The effect of shaft misalignment and pinion mass unbalance on hypoid gear dynamic response is evaluated under different assembly conditions. A nonlinear 14-DOF lumped parameter model based on coupled multi-body dynamics is applied by considering large rotational displacement in torsional direction. Results demonstrate three main influences from shaft misalignment and mass unbalance including speed and torque fluctuation as well as external bending moment on pinion shaft. It is also observed that bending moment generated can exert additional load on pinion shaft bearings which is found to be more sensitive to misalignment angle compared to dynamic response along line-of-action. Besides, shaft misalignment and mass unbalance excitation will interact with gear internal excitation from transmission error (TE) which can affect mesh parameters.

Energy and Exergy Evaluation of a Two-Stage Axial Vapour Compressor on the LNG Carrier.

Data from a two-stage axial vapor cryogenic compressor on the dual-fuel diesel–electric (DFDE) liquefied natural gas (LNG) carrier were measured and analyzed to investigate compressor energy and exergy efficiency in real exploitation conditions. The running parameters of the two-stage compressor were collected while changing the main propeller shafts rpm. As the compressor supply of vaporized gas to the main engines increases, so does the load and rpm in propulsion electric motors, and vice versa. The results show that when the main engine load varied from 46 to 56 rpm at main propulsion shafts increased mass flow rate of vaporized LNG at a two-stage compressor has an influence on compressor performance. Compressor average energy efficiency is around 50%, while the exergy efficiency of the compressor is significantly lower in all measured ranges and on average is around 34%. The change in the ambient temperature from 0 to 50 °C also influences the compressor’s exergy efficiency. Higher exergy efficiency is achieved at lower ambient temperatures. As temperature increases, overall compressor exergy efficiency decreases by about 7% on average over the whole analyzed range. The proposed new concept of energy-saving and increasing the compressor efficiency based on pre-cooling of the compressor second stage is also analyzed. The temperature at the second stage was varied in the range from 0 to −50 °C, which results in power savings up to 26 kW for optimal running regimes.