On Dynamic Loads in Parallel Shaft Transmissions: Part II—Parameter Study

1988 ◽  
Vol 110 (2) ◽  
pp. 226-229 ◽  
Author(s):  
H.-H. Lin ◽  
R. L. Huston ◽  
J. J. Coy
Keyword(s):  
Natural Frequency ◽  
Dynamic Loading ◽  
Dynamic Load ◽  
Spur Gear ◽  
Transmission Model ◽  
Parameter Study ◽  
Factors Affecting ◽  
Rotating Speed ◽  
Tooth Stiffness ◽  
Speed Up

Solutions to the governing equations of a spur gear transmission model, developed in Part I, are presented. Factors affecting the dynamic load are identified. It is found that the dynamic load increases with operating speed up to a system natural frequency. At operating speeds beyond the natural frequency the dynamic load decreases dramatically. Also, it is found that the applied load and shaft inertia have little effect upon the dynamic load. Damping and friction decrease the dynamic load. Finally, tooth stiffness has a significant effect upon dynamic loading: the higher the stiffness, the lower the dynamic loading. Also, the higher the stiffness the higher the rotating speed required for peak dynamic response.

On Dynamic Loads in Parallel Shaft Transmissions: Part I—Modelling and Analysis

1988 ◽  
Vol 110 (2) ◽  
pp. 221-225 ◽  
Author(s):  
H.-H. Lin ◽  
R. L. Huston ◽  
J. J. Coy
Keyword(s):  
Contact Stress ◽  
Spur Gear ◽  
Power Source ◽  
Solution Procedure ◽  
Dynamic Loads ◽  
Parameter Study ◽  
Factors Affecting ◽  
Stress Load ◽  
Tooth Stiffness ◽  
Local Compliance

A model of a simple parallel-shaft, spur-gear transmission is presented. The model is developed to simulate dynamic loads in power transmissions. Factors affecting these loads are identified. Included are shaft stiffness and inertia, load and power source inertia, tooth geometry, tooth stiffness, local compliance due to contact stress, load sharing, and friction. Governing differential equations are developed and a solution procedure is outlined. A parameter study of the solutions is presented in Part 2.

Dynamic Spur Geared Rotor Analysis of a Multi-Shaft Turbine With Gear Parameters

2015 ◽  
Author(s):  
T. N. Shiau ◽  
C. R. Wang ◽  
D. S. Liu ◽  
W. C. Wang ◽  
W. C. Hsu
Keyword(s):  
Natural Frequency ◽  
Spur Gear ◽  
Turbine Rotor ◽  
Rotor System ◽  
Assumed Mode Method ◽  
Rotating Speed ◽  
System Equation ◽  
Unbalance Response ◽  
Mode Method ◽  
Main Components

The dynamic analysis of the multi-shaft turbine rotor equipped with a spur gear pair for the various gear parameters is studied. Main components of the multi-shaft turbine rotor system include the outer shaft, the inner shaft, the impeller shaft, the oil shaft and the ball bearings. The global assumed mode method (GAMM) is applied to model the rotor motion and the system equation of motion is formulated using Lagrange’s approach. The dynamic behavior of the geared multi-shaft turbine rotor system includes the natural frequency, mode shape and unbalanced response. Numerical results show that large vibration amplitude is observed in steady state at self-excited rotating speed adjacent to the natural frequency. There is no influence of the various pressure angle, modulus, and modification coefficients on unbalance response. Contrary to above cases, the variation of the system unbalance response is dominated by the tooth types rather than the other gear parameters.

Effect of Contact Ratio on Spur Gear Dynamic Load With No Tooth Profile Modifications

1996 ◽  
Vol 118 (3) ◽  
pp. 439-443 ◽  
Author(s):  
Chuen-Huei Liou ◽  
Hsiang Hsi Lin ◽  
F. B. Oswald ◽  
D. P. Townsend
Keyword(s):  
Dynamic Load ◽  
Spur Gear ◽  
Tooth Size ◽  
Contact Ratio ◽  
Gear Dynamics ◽  
Wide Range ◽  
Gear Contact ◽  
Center Distance ◽  
Selection Of ◽  
Better Than

This paper presents a computer simulation showing how the gear contact ratio affects the dynamic load on a spur gear transmission. The contact ratio can be affected by the tooth addendum, the pressure angle, the tooth size (diametral pitch), and the center distance. The analysis presented in this paper was performed by using the NASA gear dynamics code DANST. In the analysis, the contact ratio was varied over the range 1.20 to 2.40 by changing the length of the tooth addendum. In order to simplify the analysis, other parameters related to contact ratio were held constant. The contact ratio was found to have a significant influence on gear dynamics. Over a wide range of operating speeds, a contact ratio close to 2.0 minimized dynamic load. For low-contact-ratio gears (contact ratio less than two), increasing the contact ratio reduced gear dynamic load. For high-contact-ratio gears (contact ratio equal to or greater than 2.0), the selection of contact ratio should take into consideration the intended operating speeds. In general, high-contact-ratio gears minimized dynamic load better than low-contact-ratio gears.

Pore Pressure Build-up of Silt Soft Clay under Dynamic Loading at Zhoushan Islands

2012 ◽  
Vol 594-597 ◽  
pp. 460-464
Author(s):  
Qian Shi ◽  
Kui Zhou ◽  
Qiang Li
Keyword(s):  
Pore Pressure ◽  
Dynamic Loading ◽  
Dynamic Load ◽  
Soft Clay ◽  
Test System ◽  
Dynamic Responses ◽  
Minor Effect ◽  
Consolidation Pressure ◽  
Anisotropic Consolidation ◽  
Pore Pressure Build Up

The mechanism of dynamic tri-axial test is introduced in this paper and the dynamic responses of silt soft clay at Zhoushan are studied using a dynamic tri-axial test system. The laws of pore pressure build-up of the silt clay are obtained which are affected by the consolidation pressure and dynamic load. The greater the consolidation pressure and the dynamic loading is, the more the build-up of pore pressure is. However, the dynamic load has minor effect on pore pressure build-up under the anisotropic consolidation.

scholarly journals Fluid-Induced Vibration Elimination of a Rotor/Seal System with the Dynamic Vibration Absorber

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Qi Xu ◽  
Junkai Niu ◽  
Hongliang Yao ◽  
Lichao Zhao ◽  
Bangchun Wen
Keyword(s):  
Natural Frequency ◽  
Nonlinear Differential Equations ◽  
Damping Ratio ◽  
Force Model ◽  
Vibration Absorbers ◽  
Dynamic Vibration Absorber ◽  
Major Purpose ◽  
Rotating Speed ◽  
Dynamic Vibration ◽  
Nonlinear Responses

The dynamic vibration absorbers have been applied to attenuate the rotor unbalance and torsional vibrations. The major purpose of this paper is to research the elimination of the fluid-induced vibration in the rotor/seal system using the absorber. The simplified rotor model with the absorber is established, and the Muszynska fluid force model is employed for the nonlinear seal force. The numerical method is used for the solutions of the nonlinear differential equations. The nonlinear responses of the rotor/seal system without and with the absorber are obtained, and then the rotating speed ranges by which the fluid-induced instability can be eliminated completely and partially are presented, respectively. The absorber parameters ranges by which the instability vibration can be eliminated completely and partially are obtained. The results show that the natural frequency vibration due to the fluid-induced instability in the rotor/seal system can be eliminated efficiently using the absorber. The appropriate natural frequency and damping ratio of the absorber can extend the complete elimination region of the instability vibration and postpone the occurrence of the instability vibration.

Transient Thermoelastohydrodynamic Study of Tilting-Pad Journal Bearings Under Dynamic Loading

1998 ◽  
Vol 120 (2) ◽  
pp. 405-409 ◽  
Author(s):  
P. Monmousseau ◽  
M. Fillon ◽  
J. Freˆne
Keyword(s):  
Steady State ◽  
Dynamic Loading ◽  
Dynamic Load ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Maximum Temperature ◽  
Tilting Pad ◽  
Transient Period ◽  
Final Steady State ◽  
Tilting Pad Journal Bearings

Nowadays, tilting-pad journal bearings are submitted to more and more severe operating conditions. The aim of this work is to study the thermal and mechanical behavior of the bearing during the transient period from an initial steady state to a final steady state (periodic). In order to study the behavior of this kind of bearing under dynamic loading (Fdyn) due to a blade loss, a nonlinear analysis, including local thermal effects, realistic boundary conditions, and bearing solid deformations (TEHD analysis) is realized. After a comparison between theoretical results obtained with four models (ISO, ADI, THD, and TEHD) and experimental data under steady-state operating conditions (static load Ws), the evolution of the main characteristics for three different cases of the dynamic load (Fdyn/Ws < 1, Fdyn/Ws = 1 and Fdyn//Ws > 1) is discussed. The influence of the transient period on the minimum film thickness, the maximum pressure, the maximum temperature, and the shaft orbit is presented. The final steady state is obtained a long time after the appearance of a dynamic load.

scholarly journals ANALYSIS OF DYNAMIC LOADING OF IMPROVED CONSTRUCTION OF A TANK CONTAINER UNDER OPERATIONAL LOAD MODES

2019 ◽  
Vol 2 ◽  
pp. 61-70
Author(s):  
Oleksij Fomin ◽  
Alyona Lovska ◽  
Oleksandr Gorobchenko ◽  
Serhii Turpak ◽  
Iryna Kyrychenko ◽  
...  
Keyword(s):  
Dynamic Loading ◽  
Dynamic Load ◽  
Operating Conditions ◽  
Dynamic Loads ◽  
The Finite Element Method ◽  
Operational Load ◽  
International Transport ◽  
Improvement Measures ◽  
Cargo Transportation

An increase in the volume of bulk cargo transportation through international transport corridors necessitates the commissioning of tank containers. Intermodalization of a tank container predetermines its load in various operating conditions depending on the type of vehicle on which it is carried: aviation, sea, air or rail. The analysis of the operating conditions of tank containers, as well as the regulatory documents governing their workload, led to the conclusion that the most dynamic loads acting on the supporting structures during transportation by rail. Namely, during the maneuvering collision of a wagon-platform, on which there are tank containers. In this case, it is stipulated that for a loaded tank container, the dynamic load is assumed to be 4g, and for an empty (for the purpose of checking the reinforcement) – 5g. It is important to note that when the tank container is underfilled with bulk cargo and taking into account movements of fittings relative to fittings, the maximum value of dynamic load can reach significantly larger values. Therefore, in order to ensure the strength of tank containers, an improvement of their structures has been proposed by introducing elastic-viscous bonds into the fittings. To determine the dynamic loading of the tank container, taking into account the improvement measures, mathematical models have been compiled, taking into account the presence of elastic, viscous and elastic-viscous bonds between the fittings, stops and fittings. It is established that the elastic bond does not fully compensate for the dynamic loads acting on the tank container. The results of mathematical modeling of dynamic loading, taking into account the presence of viscous and elastic-viscous coupling in the fittings, made it possible to conclude that the maximum accelerations per tank container do not exceed the normalized values. The determination of the dynamic loading of the tank container is also carried out by computer simulation using the finite element method. The calculation takes place in the software package CosmosWorks. The maximum values of accelerations are obtained, as well as their distribution fields relative to the supporting structure of the tank container. The developed models are verified by the Fisher criterion. The research will contribute to the creation of tank containers with improved technical, operational, as well as environmental characteristics and an increase in the efficiency of the liquid cargo transportation process through international transport corridors.

scholarly journals IDENTIFIKASI FAKTOR PENGARUH DOMINAN KETERLAMBATAN PROYEK AKIBAT RANTAI PASOK PADA PENGADAAN PELAT BETON PRACETAK

2020 ◽  
Vol 3 (4) ◽  
pp. 1295
Author(s):  
Firena Bian Saputri ◽  
Basuki Anondho
Keyword(s):  
Supply Chain ◽  
Human Error ◽  
Concrete Slab ◽  
Precast Concrete ◽  
Influence Factors ◽  
Concrete Slabs ◽  
Literature Study ◽  
Factors Affecting ◽  
Project Duration ◽  
Speed Up

One way that can be done to speed up the duration of the project is to use precast concrete slabs. However, the use of precast concrete slab elements in the project can be ineffective if in the order stage, production stage, until the delivery stage of precast concrete elements to the project site is not managed properly, which can cause delays in project duration. Therefore, the use of precast concrete slabs is very dependent on the supply chain management. To anticipate this risk, it is necessary to identify what are the dominant factors in the supply chain that affect the procurement of precast concrete slabs which can cause delays in project duration. The initial influence factors were collected through a literature study and interviews with a number of practitioners, followed by a survey using a questionnaire to a number of project actors in projects using precast concrete slabs. The Likert scale 1-5 is used to measure the level of influence of a factor identified on project delays. By using factor analysis techniques, as many as three groups of dominant supply chain factors affecting the procurement of precast concrete slabs were found, namely special factors, technical factors, and human error factors.ABSTRAKSalah satu cara yang dapat dilakukan demi mempercepat durasi proyek adalah menggunakan pelat beton pracetak. Namun, penggunaan elemen pelat beton pracetak di proyek bisa tidak efektif apabila dalam tahap pemesanan, tahap produksi, hingga tahap pengiriman elemen beton pracetak ke lokasi proyek tidak dikelola dengan baik, sehingga dapat menyebabkan keterlambatan durasi proyek. Oleh sebab itu, penggunaan pelat beton pracetak sangat bergantung pada manajemen rantai pasokannya. Untuk mengantisipasi risiko tersebut, perlu adanya identifikasi mengenai faktor dominan apa saja pada rantai pasok yang mempengaruhi pengadaan pelat beton pracetak yang dapat menyebabkan keterlambatan durasi proyek. Faktor pengaruh awal dikumpulkan melalui studi literatur dan wawancara kepada sejumlah praktisi, dilanjutkan dengan survei menggunakan kuesioner kepada sejumlah pelaku proyek di proyek yang menggunakan pelat beton pracetak. Skala Likert 1-5 digunakan untuk mengukur tingkat pengaruh suatu faktor yang diidentifikasi terhadap keterlambatan proyek. Dengan menggunakan teknik analisis faktor, sebanyak tiga kelompok faktor dominan rantai pasok yang berpengaruh pada proses pengadaan pelat beton pracetak ditemukan, yaitu faktor khusus, faktor teknis, dan faktor human error.

The Effect of Tooth Wear on the Vibration Spectrum of a Spur Gear Pair

2001 ◽  
Vol 123 (3) ◽  
pp. 311-317 ◽  
Author(s):  
J. H. Kuang ◽  
A. D. Lin
Keyword(s):  
Dynamic Load ◽  
Sliding Wear ◽  
Vibration Spectrum ◽  
Tooth Wear ◽  
Spur Gear ◽  
Damping Factor ◽  
Gear Pair ◽  
Mesh Stiffness ◽  
Wear Process ◽  
The Mathematical Model

In this paper, the effect of tooth wear on the vibration spectrum variation of a rotating spur gear pair is studied. In order to approximate the dynamic characteristics of an engaging spur gear pair, the load sharing alternation, position dependent mesh stiffness, damping factor and friction coefficient are considered in the mathematical model. The wear prediction model proposed by Flodin et al. is used to simulate the tooth profile wear process. The variation of the vibration spectra introduced from the interaction between the sliding wear and the dynamic load is simulated and analyzed. Numerical results indicate that the dynamic load histogram of an engaging spur gear pair may change greatly with the tooth wear. This finding implies that the variation of the gear vibration spectrum might be used to monitor the tooth wear of an engaging spur gear pair.

scholarly journals Effect of Tooth Deformation Due to Plastic Flow on Dynamic Load and Pitting in Spur Gear

1975 ◽  
Vol 41 (345) ◽  
pp. 1587-1596
Author(s):  
Kazunori ICHIMARU ◽  
Fujio HIRANO ◽  
Michio HATAMOTO
Keyword(s):  
Plastic Flow ◽  
Dynamic Load ◽  
Spur Gear
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