scholarly journals Advanced Industrial Turbine Gear Calculation Methods

1978 ◽  
Author(s):  
Manfred Hirt
Keyword(s):  
Vibration Analysis ◽  
Load Capacity ◽  
Bending Stress ◽  
Calculation Methods ◽  
Tooth Width

Calculation of industrial turbine gears is more than calculation of load capacity concerning Hertzian pressure, bending stress, and scoring phenomena. It also includes, for example, a complete vibration analysis of the gear, shaft, and bearing systems. Some newer methods used in the German practice for these calculations and also for determining exact tooth width corrections and some aspects of the new ISO calculation methods are discussed.

Bending Fatigue Tests of High Speed Spur Gears

1981 ◽  
Vol 103 (2) ◽  
pp. 466-473 ◽  
Author(s):  
I. Yuruzume ◽  
H. Mizutani
Keyword(s):  
High Speed ◽  
Normal Load ◽  
Load Capacity ◽  
Spur Gear ◽  
Fatigue Tests ◽  
Spur Gears ◽  
Bending Fatigue ◽  
Tooth Width ◽  
Bending Load ◽  
Bending Fatigue Strength

Effects of addendum modification of tooth profiles on the bending fatigue strength of high speed spur gear are discussed in this presentation: A JIS Class O Spur gear of m3, α20 deg, Z1 27, and made of AMS 6260 (AISI 9310) steel precisely ground after carburizing and hardening was meshed with the other gear of Z2 77 and operated at 8550 rpm. In this running test, bending load capacity and running performance comparisons between the gear with standard tooth profile and the two shifted gears of which tooth addendum modification coefficients were 0.35 and 0.8. The maximum normal load of the gear with addendum modification coefficient 0.8 at 107 (10 million) cycles was 1.8 kNsmm per unit tooth width. The maximum Hertz stress of this gear was 2.43 × 109 Nsm2. The allowable normal load of the gear with 0.8 was higher than that of the standard gear by 87 percent and higher than of the 0.35 profile shifted gears by 20 percent.

Pitting Load Capacity of Helical Gears

2007 ◽  
Author(s):  
Bernd-Robert Ho¨hn ◽  
Peter Oster ◽  
Gregor Steinberger
Keyword(s):  
Calculation Method ◽  
Load Distribution ◽  
Load Capacity ◽  
Test Results ◽  
Calculation Methods ◽  
Helical Gears ◽  
Capacity Calculation ◽  
Overlap Ratio ◽  
Tooth Flank

In experimental analyzes the pitting load capacity of case carburized spur and helical gears is determined in back-to-back test rigs. The research program with one type of spur and 8 types of helical gears includes tests for the determination of influences of varying load distribution, overlap ratio and transmission ratio. The test results are presented and evaluated on the basis of the pitting load capacity calculation methods of ISO 6336-2/DIN 3990, part 2. A new DIN/ISO compatible calculation method for pitting load capacity is presented. This new calculation method comprehends helical gears more adequate than ISO 6336-2 / DIN 3990, part 2 and has the possibility to consider tooth flank modifications. The new calculation method is applied on test results and gears of a calculation study. It shows better accordance with the experimental test results than the present ISO 6336-2 / DIN 3990, part 2.

Hydrodynamic Damping and Added Mass of Modern Screw Propellers

2017 ◽  
Author(s):  
Stefan Krüger ◽  
Wilfried Abels
Keyword(s):  
Vibration Analysis ◽  
Added Mass ◽  
Design Phase ◽  
Empirical Methods ◽  
Calculation Methods ◽  
Slow Steaming ◽  
Hydrodynamic Damping ◽  
Mass Moment ◽  
Mass Moment Of Inertia ◽  
Semi Empirical

The operation of ships with “slow-steaming” poses new problems for the torsional vibration analysis of the drive train. It is well known that the propeller determines the essential part of the mass moment of inertia and the system damping. Both values are determined during the initial design phase by semi-empirical methods with have originally been developed by Schwanecke and Grim between 1970 and 1980. Since then, propeller designs have changed significantly and it is unclear if modern propeller designs are still covered by these calculation methods. The paper suggests an extension of Grim’s and Schwanecke’s method for modern screw propellers in homogeneous and unsteady flow.

scholarly journals Pile Load Capacity – Calculation Methods

2015 ◽  
Vol 37 (4) ◽  
pp. 83-93 ◽  
Author(s):  
Bogumił Wrana
Keyword(s):  
Load Capacity ◽  
Cohesive Soils ◽  
Calculation Methods ◽  
Cohesionless Soils ◽  
Short Term ◽  
Pile Capacity ◽  
Static Tests ◽  
Capacity Calculation ◽  
Foundation Pile

Abstract The article is a review of the current problems of the foundation pile capacity calculations. The article considers the main principles of pile capacity calculations presented in Eurocode 7 and other methods with adequate explanations. Two main methods are presented: α – method used to calculate the short-term load capacity of piles in cohesive soils and β – method used to calculate the long-term load capacity of piles in both cohesive and cohesionless soils. Moreover, methods based on cone CPTu result are presented as well as the pile capacity problem based on static tests.

Assessment of the Vibration Excitation and Optimization of Cylindrical Gears

2011 ◽  
Author(s):  
Bernd-Robert Ho¨hn ◽  
Michael Heider ◽  
Karsten Stahl ◽  
Michael Otto ◽  
Jens Bihr
Keyword(s):  
Load Capacity ◽  
High Load ◽  
Noise Generation ◽  
Variable Speed ◽  
Dynamic Effects ◽  
Calculation Methods ◽  
Gear Mesh ◽  
Cylindrical Gears ◽  
Resonance Behavior ◽  
High Load Capacity

Vibration and noise generation of gear stages is mainly caused by the excitation of the gear mesh. This excitation is significantly influenced by geometry of the tooth. Here, both the macro-geometry (main geometry) and the micro-geometry (flank corrections) of the teeth are important. Corrections of the tooth flanks usually have to meet the requirements of low excitation and high load capacity. Furthermore it is oftenly necessary, especially for transmissions with variable speed, to account for the dynamic effects (e.g. resonance behavior) of noise excitation. The computer program DZP (Dynamic Tooth Force Program) provides extensive calculation methods for analyzing mesh excitation and transmission dynamics. The frame program DZPopt provides extensive possibilities to determine an optimum excitation flank correction based on the calculation capabilities of DZP.

FEM Analysis for Bending Strength of Active Gear Design

2012 ◽  
Vol 487 ◽  
pp. 212-215
Author(s):  
Wei Li ◽  
Ning Liu ◽  
Ning Li ◽  
Wei Zhao ◽  
Jun Ping Liu
Keyword(s):  
High Performance ◽  
Bending Strength ◽  
Design Method ◽  
Reference Value ◽  
Fem Analysis ◽  
Bending Stress ◽  
Gear Design ◽  
Tooth Width ◽  
Active Design ◽  
Gear Rack

Gear design is based on the standard gear rack parameter in modern gear design. This makes gear design indirect and passive. However, the standard rack parameters have certain limitations on gear parameters and performances. Some good designs with nonstandard parameters are excluded. In order to meet practical requirements and improve the stress performances, a active gear design method is proposed in this paper. 3D gear modal is designed basing on active design method by PRO/E software. The bending stress of tooth root which is affected by gear shaft and tooth width is analyzed by FEM software ANSYS. This paper has a certain reference value for the gear design with high performance.

Analysis of Dynamic Contact and Carrying Capacity Factors for Super-Modulus Pinion and Rack

2015 ◽  
Vol 656-657 ◽  
pp. 622-627
Author(s):  
Qing Guo Wang ◽  
Jing Wei ◽  
Li Zhi Chen ◽  
Pan Gao
Keyword(s):  
Carrying Capacity ◽  
Dynamic Contact ◽  
Bending Stress ◽  
Tooth Width ◽  
Study Results ◽  
Engineering Significance ◽  
Hostile Environments ◽  
Influence Degree ◽  
Jack Up ◽  
Meshing Process

Jack-up platform jacking system which undertakes the weight of the platform and working load is very important during the lifting, and its performance exerts a direct influence on the safety and application effect of the whole platform. The super-modulus pinion and rack of jack-up platform jacking system are most likely to damage by fracture and fatigue pitting, which are due to the hostile environments. As a result of dynamic load, the analysis of dynamic contact has important engineering significance in an actual project. For strengthening the carrying capacity of pinion and shortening the design period, the research of carrying capacity factors is very meaningful. In this paper, the changing of stresses on the pinion and rack are gained by FEM, and main parameters that influence the carrying capacity of the pinion in a jacking system are analyzed according to the calculation method in GB standard. The study results shows the contact stresses and bending stress are higher throughout the meshing process, which implies the dangerous position of the pinion. In single meshing period, the trend of bending stress in the compression side of pinion and rack is opposite, while the bending stress in the tension side of both rack and pinion are minimum near the pitch circle. The carrying capacity of pinion can be strengthened by changing the main parameters, such as tooth width, normal modulus, pressure angle, modification coefficient, but the influence degree of each parameter is different.

scholarly journals Piles and lateral loads: comparison of calculation methods

Vestnik MGSU ◽  
2019 ◽  
pp. 1280-1291
Author(s):  
Konstantin V. Kurguzov ◽  
Igor K. Fomenko
Keyword(s):  
Mathematical Models ◽  
Load Capacity ◽  
Field Tests ◽  
Analytical Techniques ◽  
Lateral Load ◽  
Pile Foundations ◽  
Lateral Impact ◽  
Calculation Methods ◽  
Soil Model ◽  
Pile Resistance

Introduction. Calculation and analysis of pile resistance to loads remains to be a relevant problem in geoengineering. The design of pile foundations is currently performed using diverse analytical, empirical and numerical methods. However, the reliability of these methods remains to be a topic of interest among researchers and designers. This research paper analyses methods used for calculating the lateral-load capacity of piles in comparison with field-test data. Materials and methods. The paper dwells upon the development of reliable analytical expressions based on mathematical models of the pile–soil interaction. Main existing mathematical models of the soil environment, including the Mohr – Coulomb elastic ideal plastic model and the hardening soil model (HSM) were analysed. A particular attention was paid to a variety of factors affecting the pile–soil interaction, such as natural factors, pile types, pile sinking depth and technology, configurations of loads, as well as time-changed processes. A comparison of methods for calculating the lateral-load capacity of piles was conducted. To that end, calculations using the Mohr – Coulomb model and the local elastic strain theory (still required by building codes) were performed. High-level solid elements were used to develop and compute a finite-element pile-in-soil model in a spatial setting. Another model on the basis of parametric pile elements was designed using the MIDAS software. Results. It is established that the use of numerical calculation methods for evaluating the capacity and movements of pile foundations provides results comparable to those of field tests. These methods demonstrate a higher reliability compared to standardized analytical techniques. Conclusions. The reliability of numerical calculations of pile resistance to lateral impact is shown to be sufficiently high, thus being feasible for use in geoengineering. The use of these methods should be based on advanced non-linear soil models, such as HS, CamClay, etc.

scholarly journals Stress calculation on bevel gears with FEM influence vectors

2021 ◽  
Author(s):  
Frederik Mieth ◽  
Carsten Ulrich ◽  
Berthold Schlecht
Keyword(s):  
Load Capacity ◽  
Tooth Contact Analysis ◽  
Tooth Width ◽  
Tooth Stiffness ◽  
Careful Handling ◽  
Coupling Stiffness ◽  
Loaded Tooth Contact Analysis ◽  
Local Root ◽  
Local Stiffness ◽  
Root Stress

AbstractIn order to be able to carry out an optimal gear design with the aim of cost reduction and the careful handling of resources, load capacity is an important criterion for the evaluation of a gear. For the calculation of the flank and root load capacity, a precise loaded tooth contact analysis (LTCA) is necessary. With LTCA software like BECAL, influence numbers are used to calculate the deformation of the gear. These influence numbers are calculated with a BEM-module and considered for calculating the local root stress. This method simplifies the coupling stiffness in tooth width direction with a decay function and neglects the influence of local differences in tooth stiffness. In this publication, this simplification shall be questioned and evaluated.Therefore, a new method for calculating stress with FEM influence vectors is presented. This method enables the calculation of full stress tensors at any desired location in the gear with the efficiency of the influence number method. Additionally, the influence of local stiffness variations in the gear is taken into account. Various gear examples show the influence of material connections at the pinion root and the influence of the rim thickness of a wheel on the root stress. To validate the accuracy and the time efficiency of the new calculation method and to compare the results to current state-of-the-art simulations, a well-documented series of tests from the literature is recalculated and evaluated.

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