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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of the Korean Society of Mechanical Engineers A
Journal Basic Information
Journal DOI :
The Korean Society of Mechanical Engineers
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Volume & Issues
Volume 35, Issue 12 - Dec 2011
Volume 35, Issue 11 - Nov 2011
Volume 35, Issue 10 - Oct 2011
Volume 35, Issue 9 - Sep 2011
Volume 35, Issue 8 - Aug 2011
Volume 35, Issue 7 - Jul 2011
Volume 35, Issue 6 - Jun 2011
Volume 35, Issue 5 - May 2011
Volume 35, Issue 4 - Apr 2011
Volume 35, Issue 3 - Mar 2011
Volume 35, Issue 2 - Feb 2011
Volume 35, Issue 1 - Jan 2011
Selecting the target year
Development of Three-dimensional Chemotaxis Model for a Single Crawling Cell, Considering the Interaction between the Cell and Substrate
Song, Ji-Hwan ; Kim, Dong-Choul ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1355~1360
DOI : 10.3795/KSME-A.2011.35.11.1355
The interaction between the cell and the substrate is the most prominent feature affecting the migration of a crawling cell. This paper proposes a three-dimensional dynamic model using the diffuse interface description that reveals the effects of the interaction between a single crawling cell and the substrate during chemotactic migration. To illustrate the effects of interaction between the cell and the substrate, we consider the interfacial energy between the coexistent materials. Multiple mechanisms including the interface energy, chemotaxis effect, and diffusion, are addressed by employing a diffuse interface model.
Fatigue Crack Propagation and Fatigue Life Evaluation of High-Performance Steel using Modified Forman Model
Choi, Sung-Won ; Kang, Dong-Hwan ; Lee, Jong-Kwan ; Kim, Tae-Won ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1361~1368
DOI : 10.3795/KSME-A.2011.35.11.1361
Fatigue crack propagation behavior and the fatigue life in-high performance steel were investigated by means of fatigue crack propagation tests under constant loading conditions of 'R=0.1 and f=0.1 Hz', 'R=0.3 and f=0.3 Hz', and 'R=0.5 and f=0.5 Hz' for the load ratio and frequency, respectively. A modified Forman model was developed to describe the fatigue crack propagation behavior for the conditions. The modified Forman model is applicable to all fatigue crack propagation regions I, II, and III by implementing the threshold stress intensity factor range and the effective stress intensity factor range caused by crack closure. The results show that predicted fatigue lives of Forman and modified Forman models were 8,814 and 12,292 cycles, respectively when the crack propagated approximately 5.0 mm and the load ratio and frequency were both 0.1. Comparison of the test results indicates that the modified Forman model showed much more effective fatigue crack propagation behavior in high-performance steel.
Effect of Strain Rate and Material Hardness on Residual Stress in Multiple Impact Shot Peening
Kim, Tae-Woo ; Yang, Zhao-Rui ; Na, Doo-Hyun ; Lee, Young-Seog ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1369~1375
DOI : 10.3795/KSME-A.2011.35.11.1369
Shot ball impacts to materials cause residual compressive stress on their surfaces. Improving the fatigue strength of a material that has this residual compress stress is the purpose of the shot peening process. A numerical study was performed to evaluate the effect of the strain rate sensitivity and hardness of the shot ball on the residual compressive stress. We calculated the residual compressive stress due to multiple impact shot peening using ABAQUS 6.9-1. AISI 4340 steel was the material used in this study. We compared the effects of high strain rate sensitivities and low strain rate sensitivities and found that when the material's sensitivity to the strain rate increased, the residual compressive stress decreased. In addition, the residual compressive stress of low-hardness material is higher than that of high-hardness material.
Development of Evaluation Technique for Hydrogen Embrittlement Behavior of Metallic Materials Using in-situ SP Testing under Pressurized Hydrogen Gas Conditions
Shin, Hyung-Seop ; Kim, Ki-Hyun ; Baek, Un-Bong ; Nahm, Seung-Hoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1377~1382
DOI : 10.3795/KSME-A.2011.35.11.1377
Recently, alternative and novel energy resources have been developed for use in the future because of the current environmental problems and exhaustion of fossil energy resources. Hydrogen energy has many merits, such as its environmental friendliness, easy storage, and easy production, but it also has disadvantages, in that it is highly combustible and explosive. In this study, a test procedure using a simple SP test under highly pressurized hydrogen gas conditions was established. In order to evaluate its applicability, SP tests were carried out using a stainless steel (SUS316L) sample under atmospheric, pressurized helium, and pressurized hydrogen gas conditions. The results under the pressurized hydrogen gas condition showed fissuring and produced a reduction of the elongation in the plastic instability region due to hydrogen embrittlement, showing the effectiveness of the current in-situ SP test.
Design of a Gerotor Pump and Experimental Investigation of Its Volumetric Displacement Characteristics
Kim, Dae-Myoung ; Kim, Sung-Dong ; Gu, Ji-Suk ; Oh, Sung-Jin ; Ham, Young-Bog ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1383~1389
DOI : 10.3795/KSME-A.2011.35.11.1383
Gerotor-type volumetric displacement pumps are suitable for oil or water hydraulics. For this reason, many researchers have studied this topic. Gerotor pumps have been widely used in various fields. In this study, we designed a rotor profile based on an envelope of a family of curves. An analytic method for determining the volumetric displacement of the gerotor pump is verified by comparing a result obtained using CAD technology and an experimental result. Throughout the experiment, the flow rate performance was verified. In addition, we describe the design and volumetric displacement characteristics of the gerotor pump.
Biomechanical Analysis of Arm Motion during Steering Using Motion Analysis Technique
Kim, Young-Hwan ; Tak, Tea-Oh ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1391~1398
DOI : 10.3795/KSME-A.2011.35.11.1391
Biomechanical analysis of arm motion during steering was performed using a motion analysis technique. Three-dimensional position data for each part of arm are fed into an interactive model combining a musculoskeletal arm model and the mechanical steering system to calculate joint angles and torques using inverse kinematic and dynamic analyses, respectively. The analysis shows that elbow pronation/supination, wrist flexion/extension, shoulder adduction/abduction, and shoulder flexion/extension have significant magnitudes. Sensitivity analysis of the arm joint motion with respect to seating posture and steering wheel configuration is carried out to investigate the qualitative influence of the seating posture and driver's seat configuration on the steering behavior.
A Study on Structural Safety and Advanced Efficiency for a Drywell Type Reducer
Oh, Sang-Yeob ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1399~1406
DOI : 10.3795/KSME-A.2011.35.11.1399
The reducer of the mixer is one of the main parts of the processor used for water and wastewater treatment. In this study, an advanced reducer with a drywell structure was developed in order to prevent oil leakage during operation in the field. During the development of the advanced reducer prototype, a mockup, a metal mold, and a cast were made using CAD and a CNC machine. The structural safety of the reducer prototype's lower housing (drywell structure) was checked using the ALGOR commercial FEM analysis code, which yielded a von Mises stress of about 123 N/mm2, which is below the yield stress of 250 N/
, and a natural frequency of about 650-700 Hz. In addition, the torque transmission efficiency for the advanced prototype was 95.87%, which is about 8% more than that found in a previous study, 88.45%, and the sound level was below 75 dB. Furthermore, no oil leakage or abnormal sound or vibration occurred. Therefore, an optimally designed advanced reducer prototype has been successfully developed.
Full Scale Structural Testing of Small Wind Turbine Composite Blade
Kim, Hong-Kwan ; Kim, Tae-Seong ; Lee, Jang-Ho ; Moon, Byung-Young ; Kang, Ki-Weon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1407~1413
DOI : 10.3795/KSME-A.2011.35.11.1407
In this paper, the structural design for composite blade was performed and full scale structural test was conducted to verify the structural design and integrity of composite blade. Firstly, FE analysis was performed using commercial software ABAQUS under conditions of rated wind speed and Case H in IEC 61400-2. Lay-up sequence and ply thickness were designed based on FE results. And to verify the structural design, full scale structural test was conducted according to IEC 61400-2 under identical loading conditions of FE analysis. Finally, the force-deflection and local strain behavior of composite blade were evaluated.
A Quantitative Analysis of ΔK Conversion Method for the Retardation Behavior of Fatigue Crack Growth in Varying Thickness of Al 2024-T3 Sheet Alloy
Kim, Seung-Gwon ; Lee, Ouk-Sub ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1415~1422
DOI : 10.3795/KSME-A.2011.35.11.1415
Sheet aluminum alloys used in manufacturing of machine structures for transportation show the difference of crack growth speed depending on thickness under the constant fatigue stress condition. The referred thickness effect is a major fatigue failure property of sheet aluminum alloys. In this work, we identified the thickness effect in fatigue test of thick plate and thin plate of Al 2024-T3 alloy under the constant fatigue stress condition, and presented the thickness effect to a correlative equation,
which is determined by the shape factor, thickness ratio,
and the loading factor, equivalent effective stress intensity ratio depending on thickness,
. And we analyzed quantitatively the crack growth retardation behavior in thin plate compared to thick plate by the thickness effect using
conversion method. We obtained such values as decrement of thickness(DoT), decrement of stress intensity factor range,
(DoS) and identified the relation between them to present the nature of thickness effect in this work.
Learning Input Shaping Control with Parameter Estimation for Nonlinear Actuators
Kim, Deuk-Hyeon ; Sung, Yoon-Gyung ; Jang, Wan-Shik ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1423~1428
DOI : 10.3795/KSME-A.2011.35.11.1423
This paper proposes a learning input shaper with nonlinear actuator dynamics to reduce the residual vibration of flexible systems. The controller is composed of an estimator of the time constant of the nonlinear actuator dynamics, a recursive least squares method, and an iterative updating algorithm. The updating mechanism is modified by introducing a vibration measurement function to cope with the dynamics of nonlinear actuators. The controller is numerically evaluated with respect to parameter convergence and control performance by using a benchmark pendulum system. The feasibility and applicability of the controller are demonstrated by comparing its control performance to that of an existing controller algorithm.
Radius-Measuring Algorithm for Small Tubes Based on Machine Vision using Fuzzy Searching Method
Naranbaatar, Erdenesuren ; Lee, Sang-Jin ; Kim, Hyoung-Seok ; Bae, Yong-Hwan ; Lee, Byung-Ryong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1429~1436
DOI : 10.3795/KSME-A.2011.35.11.1429
In this paper, a new tube-radius-measuring algorithm has been proposed for effectively measuring the radii of small tubes under severe noise conditions that can also perform well when metal scraps that make it difficult to measure the radius correctly are inside the tube hole. In the algorithm, we adopt a fuzzy searching method that searches for the center of the inner circle by using fuzzy parameters for distance and orientation from the initial search point. The proposed algorithm has been implemented and tested on both synthetic and real-world tube images, and the performance is compared to existing circle-detection algorithms, such as the Hough transform and RANSAC methods, to prove the accuracy and effectiveness of the algorithm. From this comparison, it is concluded that the proposed algorithm has excellent performance in terms of measurement accuracy and computation time.
Prediction of Width-Direction Asymmetric Deformation Behavior and Its Setup Model in Plate Rolling
Byon, Sang-Min ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1437~1443
DOI : 10.3795/KSME-A.2011.35.11.1437
Thick plates produced by the rolling process are used as the basic elements of ship structures. In this paper, we present a setup model for controlling the asymmetric factors causing plate bending in the width direction during plate rolling. A series of three-dimensional finite element analyses is conducted to predict the relationship between various asymmetric factors and plate bending. The setup model is developed by performing regression on the relationship to produce linear equations with several nondimensional parameters. The setup model is verified with a pilot rolling test in which variations in thickness and temperature differences in the width direction exist. The results show that the bending curvatures predicted by the model are in fairly good agreement with the measured results for those asymmetric factors.
Life and Performance Degradation Characteristics for Small-Sized Plug-In Type Pneumatic Manifold Valves
Kang, Bo-Sik ; Lee, Choong-Sung ; Kim, Hyoung-Eui ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1445~1451
DOI : 10.3795/KSME-A.2011.35.11.1445
Pneumatic valves are widely used parts that have the ability to control the air supplied to automation systems. However, if failure occurs in a pneumatic valve, it may affect the entire system and could lead to huge losses, depending on the characteristics of the system at the time of failure. Because of this significant risk and the level of consumer demand for reliability, there has been much study on ensuring the reliability of products by predicting valve lifetime distributions and degradation characteristics. In this paper, in order to determine the main factors useful for predicting the lifetime of a pneumatic valve, the scale parameter and
life time value of the widely used plug-in-type pneumatic manifold valves were measured using complete observational data on the valve lifetimes. And also the property of life distribution has been distribution-suitabilityreviewed by correlation coefficients, the degradation characteristics of valve has been presented by the result of analysis through dynamic response time test and leakage test.
Contact Surface Fatigue Life for RPG System
Nam, Hyoung-Chul ; Kwon, Soon-Man ; Shin, Joong-Ho ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1453~1459
DOI : 10.3795/KSME-A.2011.35.11.1453
A roller pinion gear (RPG) system composed of either a pin or a roller and its conjugated cam gear can improve the gear endurance from that of a conventional gear system by reducing the sliding contact while increasing the rolling motion. In this paper, we first proposed the exact cam gear profile and the self-intersection condition obtained when the profile shift coefficient is introduced. Then, we investigated the Hertzian contact stresses and the load stress factors while the varying the shape design parameters to predict the gear surface fatigue life, which is strongly related to the gear noise and vibration at the contact patch. The results show that the pitting life can be extended significantly by increasing the profile shift coefficient.
Effects of Axial Misalignments on the Torque Specimens Using Finite Element Analysis
Kim, Ju-Hee ; Kim, Yun-Jae ; Huh, Yong-Hak ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1461~1469
DOI : 10.3795/KSME-A.2011.35.11.1461
Using three-dimensional (3-D) FE analyses, this paper provides a method for analyzing the effects on stresses and strains produced by angular and concentric misalignment of a test specimen for a torsion test. To quantitativele compare of the FE results, the average bending strain for the angular, concentric, and combined misalignment was proposed. To verify the effects of axial misalignment of the test specimens, we used both circular and tubular specimens. From the FE results, we proposed general predictions for the effects caused by the various types of axial misalignment and its direction. In addition, we confirmed the effect of initial yielding moment based on the initial yielding condition for axial misalignment of specimens in torsion tests.
Development of a Finite Element Program for Determining Mat Pressure in the Canning Process for a Catalytic Converter
Chu, Seok-Jae ; Lee, Young-Dae ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1471~1476
DOI : 10.3795/KSME-A.2011.35.11.1471
The catalytic converter in the front part of an automobile's exhaust system converts toxic exhaust gas into nontoxic gas. The substrate in the central part of the converter has a circular or oval-shaped cross section and fine lattice-shaped walls. In the canning process, the substrate is wrapped in mats and inserted into a can. During this process, mat pressure is induced, which may cause brittle fracturing in the substrate. In this paper, a finite element program for determining the mat pressure distribution was developed to avoid these fractures. The program was created in Microsoft EXCEL, so the input and output procedures are relatively simple. It was assumed that the substrate is rigid, the mat is material nonlinear, and the can is linear elastic. The can is modeled as a beam element to resist both bending and uniform tension/compression. The number of elements is fixed to 35, and the number of iterations, to 20. The solutions are compared to ABAQUS solutions and found to be in good agreement.
Experimental Study on the Reduction of Vibration of Gear Trains Due to a One-Way Clutch
Cheon, Gill-Jeong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1477~1482
DOI : 10.3795/KSME-A.2011.35.11.1477
Using a one-way clutch has been reported to be very effective in reducing the vibration of gear pairs. However, study on the effect of using a one-way clutch has been based on numerical analysis only, and no experimental study has yet been executed. Hence, in this study, experiments to verify the effectiveness of using a one-way clutch to reduce the torsional vibration have been executed. Dynamic responses over a wide range of speeds have been compared for various numbers and positions of the clutch. The results of the experiments verified that a one-way clutch is effective in reducing the vibration by decreasing the tooth mesh vibration as well as the vibration transmitted from the input shaft.
Start and Stop Characteristics of Single-Rod Electro-Hydrostatic Actuator
Jung, Gyu-Hong ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1483~1490
DOI : 10.3795/KSME-A.2011.35.11.1483
Electro-hydrostatic actuators(EHAs), which are usually composed of a direct motor-driven hydraulic pump and a cylinder, have been widely adopted as aircraft actuation systems because of their benefits in terms of improved efficiency, weight savings and the fact that they use a standalone power source. Since the recent trend in construction vehicles has been focus on energy savings in their hydraulic systems, EHAs are expected to be potential substitutes for conventional power transmission, since they are capable of energy recovery as well as highly efficient pump control. In this paper, the start and stop characteristics of EHAs were investigated through cracking pressure analysis of the pilot-operated check valve(PCV), which enables the cylinder to standstill against an external load with no holding effort from the hydraulic pump. A mathematical model that includes the load dynamics and the EHA's internal hydraulic circuit was derived for simulation with the MATLAB Simulink package. This model verified the PCV's opening and closing sequence, which in turn affects the EHA's start and stop characteristics.
Mechanism for Vertical Welding for a Combination of Circular and Linear Paths
Noh, Tae-Yang ; Jang, Won-Tek ; Kim, Jae-Kwon ; Park, Jong-Yoen ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1491~1497
DOI : 10.3795/KSME-A.2011.35.11.1491
One of the primary concerns in the design of welding devices is how to reduce the distance error between the welding path and the torch, especially when the path has a combination of circular and linear parts. This study investigated a mechanism for reducing the tracking error in the tangent area of a circular and linear path. A portable welding device, called a carriage, has been designed for a specific welding path by considering the distance error deviation. This welding carriage for vertical cover plate welding consists of a rail, a welding torch and the carriage body itself.
Macroscopic High-Temperature Structural Analysis Model for a Small-Scale PCHE Prototype (I)
Song, Kee-Nam ; Lee, Heong-Yeon ; Kim, Chan-Soo ; Hong, Sung-Duk ; Park, Hong-Yoon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1499~1506
DOI : 10.3795/KSME-A.2011.35.11.1499
The IHX (intermediate heat exchanger) is a key component of nuclear hydrogen systems for the production of massive amounts hydrogen. The IHX transfers the
heat generated by the VHTR (very high temperature reactor) to a hydrogen production plant. The Korea Atomic Energy Research Institute established a small-scale gas loop to test the performance of key VHTR components and manufactured a small-scale PCHE (printed circuit heat exchanger) prototype, which is being considered as a candidate for the IHX, for testing in the small-scale gas loop. In this study, as a part of the high-temperature structural integrity evaluation of the small-scale PCHE prototype, we carried out high-temperature structural analysis modeling and macroscopic thermal and structural analysis for the small-scale PCHE prototype under the small-scale gas loop test conditions. This analysis serves as a precedent study to scheduled PCHE performance test in the small-scale gas loop. The results obtained in this study will be compared with the test results for the small-scale PCHE and then used to design the medium-scale PCHE prototype.
Injection Molding and Structure Analysis of Inline Skate Frames Using FEA
Park, Chul-Woo ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1507~1514
DOI : 10.3795/KSME-A.2011.35.11.1507
Injection molding is the most commonly used process that uses plastic material. Today, the uses of plastic material are continuously increasing, and the range of application is also being extended by the development of novel materials. An inline skate consists of 4 components: the boot, frame, wheel and brake. Among these components, the frame is the most critical. The injection formability for a variety of injection materials for inline skate frames was studied. We also studied the injection formability of the product for various sizes of the runner and gate. In this study, injection molding analysis was performed using MOLDFLOW, and structural analysis was performed using ANSYS.
Structural Evaluation of the 300 Ton Goliath Crane
Shin, Sung-Hwan ; Kim, Jeong-Kyeong ; Song, Chul-Ki ; Kim, Bum-Keun ; Bae, Tae-Han ; Kim, Joong-Moon ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1515~1520
DOI : 10.3795/KSME-A.2011.35.11.1515
Structural analysis and evaluation for the 300ton Goliath Crane were conducted with an FEM tool. The Golliath Crane has a 300 ton hoisting weight, a 110 m span and a 50 m lift. All loads such as the self weight, crane traveling load, trolley traveling load, wind load, and earthquake force, etc., that are indicat in the reference standards, were inputted as various severe conditions affecting the crane. The deformation and equivalent stress (von Mises stress) were evaluated for the crane structures.
Material Properties for Reliability Improvement in the FEA Results for Rubber Parts
Baek, Un-Cheol ; Cho, Maeng-Hyo ; Hawong, Jai-Sug ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1521~1528
DOI : 10.3795/KSME-A.2011.35.11.1521
We studied the material properties for reliability improvement in finite element analysis results for a nitrile butadiene rubber hub-bearing seal and for a carbon-filled rubber mount used in a vehicle. It was difficult to measure the material properties of hundreds of types of rubber for the mount design. Thus, we suggested that the engineering stressstrain relations from pure shear test data could be synthesized by using simple tension data and Poisson's ratio. We defined Poisson's ratio by using a function of principal stretches to synthesize the stress-strain relations for a pure shear test. A transformation of the pure shear data was applied to the experimental values to obtain the predicted results when the strain approaches 100%. In the finite element analysis for the contact force of a hub-bearing seal, the strain results that used the transformation of the pure shear data and simple tension data almost corresponded to the experimental values. Ogden constants were used to analyze.
Methodology of Engine Fitness Diagnosis Using Variation of Crankshaft Angular Speed
Lee, Byung-Yeol ; Ha, Seung-Jin ; Lim, Ock-Taeck ;
Transactions of the Korean Society of Mechanical Engineers A, volume 35, issue 11, 2011, Pages 1529~1535
DOI : 10.3795/KSME-A.2011.35.11.1529
Improvement of the thermal efficiency in operation and maintenance of low- and medium-speed engines is a kind of never-ending requirement in the maritime power plant business. For the purpose of improving engine management efficiency, a principal factor that represents the fitness of the engine should be identified. Gas pressure, gas temperature, and vibration have all been used as this factor. However, they have limitations in terms of response speed and diagnosis accuracy. The EFR (engine fitness ratio) is suggested as a new diagnostic factor in this paper. The EFR is defined as the ratio of particular frequencies in the frequency domain and represents the fitness of an engine. It is calculated from the fluctuation pattern of the crankshaft angular speed. The EFR was verified using an experimental method for a low-speed engine and an analytic method for a medium-speed engine.