scholarly journals Mesh Force Modelling and Parametric Studies for Compound Oscillatory Roller Reducer

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Changxu Wei ◽  
Chaosheng Song ◽  
Caichao Zhu ◽  
Chengcheng Liang ◽  
Long Hu
Keyword(s):  
Analytical Model ◽  
Tooth Profile ◽  
Gear Transmission ◽  
Design Parameters ◽  
Manufacturing Error ◽  
Second Stage ◽  
Profile Equation ◽  
Manufacturing Errors ◽  
Parametric Studies ◽  
Significant Factors

AbstractA compound oscillatory roller reducer (CORR) with a first-stage gear transmission and a second-stage oscillatory roller transmission is presented. The transmission principle of oscillatory roller transmission is introduced, and the tooth profile equation of the inner gear is derived. The analytical model of mesh force considering the installation errors and manufacturing errors is proposed. Then, parametric studies considering different errors on the mesh force are conducted. Results show that the design parameters are significant factors for mesh force. The mesh force is reduced by 17% as the eccentricity of disk cam increases from 2.5 mm to 4 mm. When the radius of the movable roller increases from 7 mm to 20 mm, the mesh force decreases by 8%. As the radius of disk cam increases from 125 mm to 170 mm, the mesh force is decreased by 26.5%. For the impacts of errors, the mesh force has a noticeable fluctuation when these errors exist including the manufacturing error of disk cam, the installation error of disk cam and the manufacturing error of movable roller change. The prototype of the reducer is manufactured and preliminary run-in test proved the feasibility of the transmission principle.

Stability Analysis of Spools with Imperfect Sealing Gap Geometries

2021 ◽  
Author(s):  
Rituraj Rituraj ◽  
Rudolf Scheidl
Keyword(s):  
Stability Analysis ◽  
Analytical Model ◽  
Ritz Method ◽  
Lateral Force ◽  
Graphical Analysis ◽  
Numerical Results ◽  
Design Parameters ◽  
Analytical Expression ◽  
Parametric Studies ◽  
The Stability

Spools in hydraulic valves are prone to sticking caused by unbalanced lateral forces due to geometric imperfections of their sealing lands. This sticking problem can be related to the stability of the coaxial spool position. Numerical methods are commonly used to study this behaviour. However, since several parameters can influence the spool stability, parametric studies become significantly computationally expensive and graphical analysis of the numerical results in multidimensional parameter space becomes difficult. To overcome this difficulty, in this work, an analytical approach for studying the stability characteristics of the spool valve is presented. A Rayleigh-Ritz method is used for solving the Reynolds equation in an approximate way in order to determine an analytical expression for the lateral force on the sealing lands. This analytical expression allows stability analysis of the spool via analytical means which finally results in the expression of critical axial velocity which demarcates the regions of stable behaviour. Simplicity of the expression allows an immediate insight into the role of design parameters in the stability of the spool. To verify the analytical model, a numerical model for spool dynamics is developed in this work and the numerical results are found to match the analytical model in terms of the stability behaviour of the spool.

Research on Geometry Relationship of Pin-Rack Gearing

2011 ◽  
Vol 86 ◽  
pp. 547-551
Author(s):  
Zhan Hui Feng ◽  
Ming Kang Gou ◽  
Shao Wu
Keyword(s):  
Design Theory ◽  
Lower Cost ◽  
Tooth Profile ◽  
Design Parameters ◽  
Compact Structure ◽  
Profile Equation ◽  
Rotation Motion ◽  
Relationship Of ◽  
Rack Mechanism ◽  
Vibration Noise

The pin-rack gearing is a particular type of cycloidal gearing which transforms a rotation motion to a linear one. Comparing with rack and pinion gearing and hydraulic swing cylinder, the pin-rack gearing has a more compact structure, less mass and lower cost. Nevertheless, designers always worry about vibration, noise and low use life as pin-rack mechanism working caused by deficiency of design theory. The present research derived the pin-rack gearing tooth profile equation and studied the geometry relationship among design parameters. The results can help to improve the pin-rack gearing design.

scholarly journals Impact of Cross-Tie Properties on the Modal Behavior of Cable Networks on Cable-Stayed Bridges

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Javaid Ahmad ◽  
Shaohong Cheng ◽  
Faouzi Ghrib
Keyword(s):  
Analytical Model ◽  
Design Parameters ◽  
Reference Base ◽  
Cable Network ◽  
Cable Networks ◽  
Modal Behavior ◽  
Stiffness And Damping ◽  
Main Cables ◽  
The Impact ◽  
Selection Of

Dynamic behaviour of cable networks is highly dependent on the installation location, stiffness, and damping of cross-ties. Thus, these are the important design parameters for a cable network. While the effects of the former two on the network response have been investigated to some extent in the past, the impact of cross-tie damping has rarely been addressed. To comprehend our knowledge of mechanics associated with cable networks, in the current study, an analytical model of a cable network will be proposed by taking into account both cross-tie stiffness and damping. In addition, the damping property of main cables in the network will also be considered in the formulation. This would allow exploring not only the effectiveness of a cross-tie design on enhancing the in-plane stiffness of a constituted cable network, but also its energy dissipation capacity. The proposed analytical model will be applied to networks with different configurations. The influence of cross-tie stiffness and damping on the modal response of various types of networks will be investigated by using the corresponding undamped rigid cross-tie network as a reference base. Results will provide valuable information on the selection of cross-tie properties to achieve more effective cable vibration control.

scholarly journals Multi-stable composite twisting structure for morphing applications

2012 ◽  
Vol 468 (2141) ◽  
pp. 1230-1251 ◽  
Author(s):  
X. Lachenal ◽  
P. M. Weaver ◽  
S. Daynes
Keyword(s):  
Analytical Model ◽  
Material Properties ◽  
Degrees Of Freedom ◽  
Design Parameters ◽  
Engineering Structures ◽  
The Past ◽  
Wide Range ◽  
Morphing Structure ◽  
Low Mass ◽  
Unstable States

Conventional shape-changing engineering structures use discrete parts articulated around a number of linkages. Each part carries the loads, and the articulations provide the degrees of freedom of the system, leading to heavy and complex mechanisms. Consequently, there has been increased interest in morphing structures over the past decade owing to their potential to combine the conflicting requirements of strength, flexibility and low mass. This article presents a novel type of morphing structure capable of large deformations, simply consisting of two pre-stressed flanges joined to introduce two stable configurations. The bistability is analysed through a simple analytical model, predicting the positions of the stable and unstable states for different design parameters and material properties. Good correlation is found between experimental results, finite-element modelling and predictions from the analytical model for one particular example. A wide range of design parameters and material properties is also analytically investigated, yielding a remarkable structure with zero stiffness along the twisting axis.

Numerical Simulation of the “Floating Spiral” Pipeline Installation Procedure: Second Stage, Spiral Transportation, Behavior Under Waves

2008 ◽  
Author(s):  
Bruno Martins Jacovazzo ◽  
Fabri´cio Nogueira Correˆa ◽  
Carl Horst Albrecht ◽  
Breno Pinheiro Jacob ◽  
Fernando Gomes da Silva Torres ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Optimal Control ◽  
Environmental Conditions ◽  
Companion Paper ◽  
Time Constraints ◽  
Second Stage ◽  
Parametric Studies ◽  
Large Length ◽  
Transportation Behavior ◽  
Flat Spiral

The Floating Spiral pipeline installation method consists basically in winding the pipeline into a huge floating spiral, and towing this assembly to the installation site, where the spiral is then unwound and lowered to the seabed. In this method the pipeline is fabricated onshore, as the spiral is created, under well controlled conditions and relatively relaxed time constraints. Therefore the welds can be better inspected, which allows for optimal control of quality in pipeline manufacturing. The first stage of the installation process by this method consists in setting the pipeline afloat and winding it elastically to form a large flat spiral. This stage is studied in a companion paper [1], to be also presented at IPC2008. The second stage consists in towing the floating spiral pipeline employing standard tugboats before laying it at the installation site. The objective of this work is, therefore, to present results of parametric studies for a large length pipeline at this second stage of the Floating Spiral method. The focus now is in the pipeline behavior under wave environmental conditions during transportation. Several numerical simulations are performed and the results are discussed and compared.

Prevention of Historically Challenging Sustained Casing Pressure from Shallow Gas Through Re-Engineered Cement Design and Execution Methodology

2021 ◽  
Author(s):  
Farah Shakina Ezani ◽  
Myat Thuzar ◽  
Avinash Kishore Kumar ◽  
Chee Hen Lau
Keyword(s):  
Mitigation Measures ◽  
Design Parameters ◽  
Two Stage ◽  
Shallow Gas ◽  
Second Stage ◽  
The Past ◽  
Sustained Casing Pressure ◽  
Dual Stage ◽  
Casing Pressure ◽  
Selection Of

Abstract Sustained casing pressure (SCP) is a very costly event for any operator either at production phase or at the end of a well’s lifecycle. SCP is a result of incomplete hydraulic isolation across hydrocarbon bearing zone. In one of the gas fields in Malaysia, notoriously known for shallow gas hazard, drilled development wells which have reportedly been suffering SCP. In the past, various improvements in cement slurry design and placement methods were deployed in order to provide complete zonal isolation, especially at the shallow gas sand, yet SCP issue was encountered occasionally. In the current development campaign, different strategy to providing annulus sealing was adopted. This paper discusses proactive steps taken in the slurry design, fit together with the dual stage cementing approach, as a primary means of placing cement above the shallow hazard interval. During the design phase, essential key parameters that would lead to successful placement of cement in the annulus as well as unique slurry design that suits for two stage cementing methods were studied. Risk involved in first stage cementing is one of the most important steps that should be analyzed in detail and put mitigation measures in place to ensure the second stage cement job can be performed as planned. In addition to the slurry properties, such as fluid-loss value, gas-tightness, etc., thickening time and top of cement (TOC) of the lead slurry in the first stage cement job has become enormously critical in designing dual stage cementing job in order to assure cement ports in the stage collar are not covered with hard cement forcing the termination of second stage job prematurely. Besides cementing design, careful selection of the stage collar location and casing annulus packer in the string is also of significant importance in leading to successful two stage cement job. Two development wells with above approached has been delivered and no sustained casing pressure has been experienced. This proactive approach to use two stage cementing as primary plan has proven to successfully eliminate the risk of SCP, which was a frequent struggle in their sister wells drilled with primary cementing in the past in the same field. The risk analysis combined with careful considerations of critical cementing design parameters and selection of stage tool location have become a novel approach to combat against SCP in this gas field.

A new analytical model for reliability analysis of a launch vehicle system with limited test data

2018 ◽  
Vol 233 (9) ◽  
pp. 3482-3495
Author(s):  
V Murugesan ◽  
Sreejith Plappillimadam ◽  
VJ Saji ◽  
SS Maruthi ◽  
AK Anilkumar
Keyword(s):  
Reliability Analysis ◽  
Analytical Model ◽  
Test Data ◽  
Weighting Factor ◽  
Design Parameters ◽  
Launch Vehicles ◽  
Minimum Number ◽  
First Time ◽  
Propellant Rocket

Reliability is one of the critical design parameters for the launch vehicles and its systems. When the systems are ready to fly the first time, only limited test data are available and accordingly reliability assessed will be very low. However, in most cases, the new systems are derived and developed using the knowledge and experience gained from the heritage systems to meet the fresh challenges. Hence, the reliability assessed with the minimum number of tests done on the new system does not truly reflect the inherent reliability of the system. In this paper, an approach and a new analytical model are developed for the reliability assessment of systems with limited test data, giving an accurate weighting for the tests and flight experiences with similar systems. The method gives a systematic procedure for arriving at the weighting factor for test data of the pedigree system, with due consideration of the similarities between the systems and various factors influencing system reliability. The method is illustrated with a case study of a newly developed liquid propellant rocket system. The model is validated using the available test and flight data of two propulsion systems with adequate flight experience. The analytical model is generic in nature and can be applied to reliability analysis of any system, which has considerable similarities with a pedigree system.

An Intelligent System for Spur Gear Design and Analysis

2001 ◽  
Author(s):  
El-Sayed Aziz ◽  
C. Chassapis
Keyword(s):  
Finite Element ◽  
Closed Form ◽  
Intelligent System ◽  
Tooth Profile ◽  
Hertzian Contact ◽  
Design Parameters ◽  
Analysis Model ◽  
Closed Form Solutions ◽  
Gear Teeth ◽  
Gear Design

Abstract A methodology for the analysis of load distribution and contact stress on gear teeth, which utilizes a combination of closed form solutions and two-dimensional finite element methods, within a constraint-based knowledge-based environment, is presented. Once the design parameters are specified, the complete process of generating the analysis model, starting from the determination of the coordinates of the tooth profile, the creation of a sector of the mating gear teeth, automatic mesh generation, boundary conditions and loading, is totally automated and transparent to the designer. The effects of non-standard geometry, load sharing on the contact zone, friction and root stresses are easily included in the model. The Finite Element Method (FEM) based results compare favorably with those obtained from closed form solutions (AGMA equations and classical Hertzian contact solution). The advantage of the approach rests in the ability to modify any of the gear design parameters such as diametral pitch, tooth profile modification etc., in an automated manner along with obtaining a better estimation of the risks of failure of the gear design on hand. The procedure may be easily extended to other types of gearing systems.

Thermal Analysis of MEMS Actuator Performance

2007 ◽  
Author(s):  
Harita Machiraju ◽  
Bill Infantolino ◽  
Bahgat Sammakia ◽  
Michael Deeds
Keyword(s):  
Power Reduction ◽  
Silicon On Insulator ◽  
Design Parameters ◽  
Experimental Measurements ◽  
Device Layer ◽  
Conduction Path ◽  
Element Analysis ◽  
Parametric Studies ◽  
Actuator Performance ◽  
Good Agreement

A MEMS based device consisting of microactuators was modeled using finite element analysis. The temperature profile of the complete package was obtained and compared to experimental measurements. Good agreement was found between the modeling and measurements. Parametric studies of potential design parameters of the chip package to decrease the power requirements to the actuators have been studied. Increasing the gap between the handle layer and the device layer of the SOI (silicon on insulator) chip from 2 to 3 microns resulted in a reduction of 10% (0.2 Watts) per beam of the actuator. A glass top chip proved to be better at reducing the power requirements for the actuators when compared to a silicon top chip. Modeling shows that relief cuts in the substrate had a larger effect on the power reduction compared to those on the top chip since the heat conduction path to the substrate is a lower resistance path. The power reduction was as high as 50% (1.1 Watts) per beam of the actuator, when the relief cut in the substrate was 50 microns.

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