scholarly journals Use of Orthogonal Arrays for Efficient Evaluation of Geometric Designs for Reducing Vibration of a Non-Pneumatic Wheel during High-Speed Rolling

2010 ◽  
Vol 38 (4) ◽  
pp. 246-275 ◽  
Author(s):  
William Rutherford ◽  
Shashank Bezgam ◽  
Amarnath Proddaturi ◽  
Lonny Thompson ◽  
John C. Ziegert ◽  
...  
Keyword(s):  
Orthogonal Array ◽  
High Speed ◽  
Contact Region ◽  
Orthogonal Arrays ◽  
Nonlinear Effects ◽  
Element Model ◽  
Geometric Design ◽  
Design Parameters ◽  
Design Variables ◽  
Wheel Vibration

Abstract During high speed rolling of a nonpneumatic wheel, vibration may be produced by the interaction of collapsible spokes with a shear deformable ring as they enter the contact region, buckle, and then snap back into a state of tension. In the present work, a systematic study of the effects of six key geometric design parameters is presented using Orthogonal Arrays. Orthogonal Arrays are part of a design process method developed by Taguchi which provides an efficient way to determine optimal combinations of design variables. In the present work, a two-dimensional planar finite element model with geometric nonlinearity and explicit time-stepping is used to simulate rolling of the nonpneumatic wheel. Vibration characteristics are measured from the FFT frequency spectrum of the time signals of perpendicular distance of marker nodes from the virtual plane of the spoke, and ground reaction forces. Both maximum peak amplitudes and RMS measures are considered. Two complementary Orthogonal Arrays are evaluated. The first is the L8 orthogonal array which considers the six geometric design variables evaluated at lower and higher limiting values for a total of eight experiments defined by statistically efficient variable combinations. Based on the results from the L8 orthogonal array, a second L9 orthogonal array experiment evaluates the nonlinear effects in the four parameters of greatest interest, (a) spoke length, (b) spoke curvature, (c) spoke thickness, and (d) shear beam thickness. The L9 array consists of nine experiments with efficient combinations of low, intermediate, and high value levels. Results from use of the Orthogonal Array experiments were used to find combinations of parameters which significantly reduce peak and RMS amplitudes, and suggest that spoke length has the greatest effect on vibration amplitudes.

Structure Optimization Design for the Bed of Gear Hobbing Machine

2013 ◽  
Vol 765-767 ◽  
pp. 176-180
Author(s):  
Rong Chuang Zhang ◽  
Ao Xiang Liu ◽  
Jun Wang ◽  
Wan Shan Wang
Keyword(s):  
Optimization Design ◽  
Optimal Solution ◽  
Element Model ◽  
Weighting Coefficient ◽  
Design Parameters ◽  
Analytic Hierarchy ◽  
Design Variables ◽  
Gear Hobbing ◽  
Vibration Modal ◽  
Hierarchy Process

In the optimization design of the gear hobbing machine bed, the finite element model is build and the static analysis and vibration modal analysis are performed. Then sensitivity analysis is used to gain the main design parameters which influence the bed property most. Furthermore, the multi-objective optimization design of the bed is performed in ANSYS Workbench with these design parameters as the design variables. At last, after all optimum proposals are showed up, Analytic Hierarchy Process is used to determine the weighting coefficient, and the most optimal solution is found out. As a result, the dynamic and static performances of the machine bed are improved under control of the machine bed mass.

scholarly journals Research on character of screw pile group composite foundation used in high-speed railway

2019 ◽  
Vol 265 ◽  
pp. 05010
Author(s):  
Maocai Zhao ◽  
Lu Zhang
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Pile Group ◽  
Element Model ◽  
Composite Foundation ◽  
Design Parameters ◽  
High Speed Railway ◽  
Screw Pile ◽  
Side Resistance ◽  
Pile Length

As a result of rapid development of a high-speed railway and infrastructure in China in recent years, the subgrade deformation and settlement control standards put forward more stringent requirements. Based on ABAQUS 6.14, established finite element model of screw pile group composite foundation. Then obtained the settlement, axial force distribution and pile side resistance distribution of center pile of pile group. Next design parameters sensitive analysis was made, such as pile length, pile spacing and so on, in order to obtain a reasonable design pile parameters by analysis of mechanical behavior.

On the Effects of Edge Scalloping for Collapsible Spokes in a Non-Pneumatic Wheel During High Speed Rolling

2009 ◽  
Author(s):  
Maya Ramachandran ◽  
Shashank Bezgam ◽  
Lonny L. Thompson ◽  
John C. Ziegert ◽  
Timothy B. Rhyne ◽  
...  
Keyword(s):  
High Speed ◽  
Acoustic Noise ◽  
Contact Region ◽  
Element Model ◽  
Design Criterion ◽  
Mode Shapes ◽  
Time Signal ◽  
Design Strategies ◽  
Pneumatic Wheel ◽  
Out Of Plane

The acoustic signature produced by non-pneumatic wheels with collapsible spokes is a critical design criterion for automotive and other mobility applications. During high speed rolling, acoustic noise may be produced by the interaction of vibrating spokes with a shear deformable ring as they enter the contact region, buckle and then snap back into a state of tension. In order to identify and help understand the causes of acoustic noise for a rolling non-pneumatic wheel, a two-dimensional finite element model with geometric nonlinearity has been utilized. The model consists of a shear ring modeled as two relatively inextensible membranes with high circumferential modulus separated by a hyper-elastic material. The temporal variation in spoke length as the spoke passes through the contact zone is extracted and used as input to a three-dimensional (3-D) model of a single spoke. The 3-D spoke model is able to capture out-of-plane vibration modes of the spoke which may contribute as a source of acoustic excitation and allows for modeling of edge scalloping. Natural frequencies and mode shapes of the various spoke design strategies are computed and correlated with the frequency response of the out-of-plane spoke vibrations. Results indicate that scalloping the edges of the spoke can dramatically reduce the amplitude of vibration, but does not have a strong effect on location of frequency peaks in a FFT of the time-signal. An optimal amount of scalloping was determined which reduces maximum vibration amplitude to an asymptotic value.

scholarly journals Research on Vibration Reduction Method of Nonpneumatic Tire Spoke Based on the Mechanical Properties of Domestic cat’s Paw Pads

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Haichao Zhou ◽  
Huiyun Li ◽  
Ye Mei ◽  
Guolin Wang ◽  
Congzhen Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Vibration Reduction ◽  
Element Model ◽  
Approximate Model ◽  
Structure Design ◽  
Peak Amplitude ◽  
Radial Excitation ◽  
Vibration Problem ◽  
Design Variables

Although there is no risk of puncture, the vibration problem caused by discontinuous structures limits nonpneumatic tire development (NPT). The vibration reduction of nonpneumatic tires is a solvable urgent problem. This current study analyzed the dynamic grounding characteristics and the vibration reduction mechanism of the cat’s paw pads and then applied the mechanical properties to the bionic design of nonpneumatic tire spokes to solve the vibration problem. Domestic cats’ paw pads’ dynamic grounding characteristics were determined using the pressure-sensitive walkway, high-speed camera, and VIC-2D. The results indicated that the mechanical characteristics of swing deformation of paw pads during the grounding process attenuated the grounding stress and buffered the energy storage to achieve the vibration reduction effect. According to the similarity transformation, a finite element model of NPT that could accurately reconstruct the structure and realistically reflect the load deformation was employed. The structure design of asymmetric arcs on the spokes’ side edges was proposed, and it can effectively reduce the radial excitation force of NPT. The three parameters, the asymmetric arc, the thickness, and the curvature of spokes, were used as design variables to maximize the vibration reduction. The orthogonal experimental, the Kriging approximate model, and the genetic algorithm were carefully selected for optimal solutions. Compared with the original tire, the results showed that peak amplitude 1, peak amplitude 2, and the root square of the optimized tire’s amplitudes were reduced by 76.07%, 52.88%, and 51.65%, respectively. These research results offer great potential guidance in the design of low-vibration NPT.

A Study of High-Speed Angular Contact Ball Bearing Thermo-Mechanical Coupling Characteristics

2013 ◽  
Vol 397-400 ◽  
pp. 131-134
Author(s):  
Chun Li Lei ◽  
Zhi Yuan Rui ◽  
Bao Cheng Zhou ◽  
Jing Fang Fang
Keyword(s):  
Contact Stress ◽  
High Speed ◽  
Thermal Deformation ◽  
Ball Bearing ◽  
Contact Region ◽  
Element Model ◽  
Machining Accuracy ◽  
Angular Contact Ball Bearing ◽  
Mechanical Coupling ◽  
Coupling Characteristics

Heat generation and deformation of bearing are key factors that influence the rigidity and machining accuracy of the high-speed precision spindle system. Based on heat transfer and thermodynamics, the finite element model of angular contact ball bearing is established for thermal deformation. The contact stress and thermal deformation are analyzed and obtained at a speed of . The results show that the maximum contact stress and thermal deflection appeared at contact region, which is in accordance with actual status. The results provide the reference and the theory basis for research into thermal deformation of bearing.

The Optimization of the Design of a Railway Wheel in Terms of the Acoustic Radiation under the Vertical Excitation

2012 ◽  
Vol 629 ◽  
pp. 548-551
Author(s):  
Bin Zhang ◽  
Lin Ya Liu ◽  
Wen Jie Shao
Keyword(s):  
High Speed ◽  
Acoustic Radiation ◽  
Radiation Power ◽  
Element Model ◽  
Acoustic Power ◽  
Environmental Noise ◽  
Railway Wheel ◽  
Vertical Excitation ◽  
Radiation Theory ◽  
Wheel Vibration

Railway wheel acoustic radiation takes a large proportion of the wheel-rail noise . This paper mainly focuses the ways to reduce railway wheel acoustic radiation to control wheel-rail acoustic radiation, and ultimately to reduce the railway environmental noise. In this paper, Optimization mathematical model of wheel acoustic radiation is built according to the wheel vibration and acoustic radiation theory, and obtaining the section optimization and acoustic radiation power of wheel by drawing up the genetic algorithm (GA) program and analyzing the acoustic radiation of the wheel according to Finite element and boundary element model. The result shows that the optimized acoustic power is reduced to some extent, even by 2dB at the peak point within 5000Hz. Since high-speed railways are put into operation in China, it has been more convenient for people to go out. However, serious railway environmental noise occurs by the way. The noise produced when the train is running affects not only passengers and working staff on the train, but also environment and residents around the railway. For this reason, to reduce the noise with proper measures is good for environment protection, sustained and healthy development of rail transportation as well. According to wheel-rail noise theory, the main approaches to reduce noise as follows:(1) Adopt damped wheel. (2) Add rubber isolation layer between tread and web of the wheel to form resilient wheel. (3) Optimize the wheel shape. (4) Reduce acoustic radiation efficiency of the wheel. This paper discusses how to reduce acoustic radiation of the wheel and railway environmental noise according to optimize the wheel shape by mainly analyzing the wheel of high frequency radiation noise.

Optimal Support Locations for a Printed Circuit Board Loaded With Heavy Components

2006 ◽  
Vol 128 (4) ◽  
pp. 449-455 ◽  
Author(s):  
Kun-Nan Chen
Keyword(s):  
Finite Element ◽  
Fundamental Frequency ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Element Model ◽  
Modal Testing ◽  
Circuit Board ◽  
Design Parameters ◽  
Printed Circuit ◽  
Design Variables

In the design of printed circuit boards (PCBs), it is preferable to increase their fundamental frequency so as to reduce the effects of the dynamic loading on them. The dynamic characteristics of a PCB carrying various electronic components and modules are most significantly affected by the geometrical and material properties of the bare board and by the boundary conditions supporting the loaded PCB. In this research, a PCB carrying a heavy CPU cooling fan and supported by six fastening screws is investigated by the modal testing and analyzed by the finite element method. After the finite element model of the PCB is verified by the experimental results, the locations of the six supporting screws are optimized to achieve a maximum fundamental frequency for the loaded PCB. The position of each fastening screw can be determined by two design variables, i.e., x and y coordinates. Two cases are studied: the symmetric case (six design parameters) with the symmetric constraint on the support locations imposed, and the asymmetric case (12 design parameters) without the constraint imposed. Finally, verification experiments are performed on the two PCBs supported by screws located at the optimal positions. Although relatively large differences between the calculated, optimized fundamental frequencies and the experimental values are observed, the experiments confirm a very significant improvement in frequency for both cases.

Design of Flexure Pivot Tilting Pads Gas Bearings for High-speed Oil-Free Microturbomachinery

2006 ◽  
Vol 129 (1) ◽  
pp. 112-119 ◽  
Author(s):  
Kyuho Sim ◽  
Daejong Kim
Keyword(s):  
High Speed ◽  
Hydrodynamic Pressure ◽  
Design Parameters ◽  
Gas Bearings ◽  
Bearing Clearance ◽  
High Speeds ◽  
Radial Stiffness ◽  
Design Variables ◽  
Final Design ◽  
Parametric Studies

This paper introduces flexure pivot tilting pad gas bearings with pad radial compliance for high-speed oil-free microturbomachinery. The pad radial compliance was for accommodation of rotor centrifugal growth at high speeds. Analytical equation for the rotor centrifugal growth based on plane stress model agreed very well with finite element method results. Parametric studies on pivot offset, preload, and tilting stiffness were performed using nonlinear orbit simulations and coast-down simulations. Higher preload and pivot offset increased both critical speeds of the rotor-bearing system and onset speeds of instability due to the increased wedge effect. Pad radial stiffness and nominal bearing clearance were very important design parameters for high-speed applications due to the physically existing rotor centrifugal growth. From the series of parametric studies, the maximum achievable rotor speed was limited by the minimum clearance at the pad pivot calculated from the rotor growth and radial deflection of pads due to hydrodynamic pressure. Pad radial stiffness also affects the rotor instability significantly. Small radial stiffness could accommodate rotor growth more effectively but deteriorated rotor instability. From parametric studies on a bearing with 28.5mm in diameter and 33.2mm in length, optimum pad radial stiffness and bearing clearance are 1-2×107N∕m and 35μm, respectively, and the maximum achievable speed appears 180krpm. The final design with suggested optimum design variables could be also stable under relatively large destabilizing forces.

scholarly journals Design of Bldc Motor for Agriculture Pump Application

2019 ◽  
Vol 8 (2) ◽  
pp. 441-446
Keyword(s):  
Design Method ◽  
Fem Analysis ◽  
Element Model ◽  
Analytical Models ◽  
Design Parameters ◽  
Analysis Tool ◽  
Bldc Motor ◽  
Analytical Design ◽  
Design Variables ◽  
Design Calculations

This paper presents the analytical design method for surface mounted BLDC motor to meet the performance requirements of submersible Pump for agriculture application. The design calculations involved assumption of various design variables viz. Stacking factor, leakage factor, Flux densities in stator and rotor yokes and flux density in the stator teeth etc. With these assumptions the geometry of the intended motor is derived. The geometrical information like the rotor diameter, rotor and stator thickness and stator teeth thickness etc. obtained from the analytical calculations are used as input to Finite Element Model (FEM) Analysis tool FEMAG. The Torque-Speed characteristics, back EMF, flux densities in various parts of the motor are obtained from FEM Analysis and the same are compared with the results obtained from Analytical design. Various designed parameters like airgap length, stack length and magnet widths are varied and their influence on the characteristics of the intended BLDC motor is obtained through FEM Analysis. Based on the analytical models and FEM Analysis the design parameters are tweaked until the desired performance for the agriculture pump is accomplished.

Optimal Support Locations for a Printed Circuit Board Loaded With Heavy Components

2005 ◽  
Author(s):  
Kun-Nan Chen
Keyword(s):  
Finite Element ◽  
Fundamental Frequency ◽  
Printed Circuit Boards ◽  
Printed Circuit Board ◽  
Element Model ◽  
Modal Testing ◽  
Circuit Board ◽  
Design Parameters ◽  
Printed Circuit ◽  
Design Variables

In the design of printed circuit boards (PCBs), it is preferable to increase their fundamental frequency so as to reduce the effects of the dynamic loading on them. The dynamic characteristics of a PCB carrying various electronic components and modulus are most significantly affected by the geometrical and material properties of the bare board and by the boundary conditions supporting the loaded PCB. In this research, a PCB carrying a heavy CPU cooling fan and supported by 6 fastening screws is investigated by the modal testing experiment and analyzed by the finite element method. After the finite element model of the PCB is verified by the experimental results, the locations of the 6 supporting screws are optimized to achieve a maximum fundamental frequency for the loaded PCB. The position of each fastening screw can be determined by two design variables, i.e., x and y coordinates. Two cases are studied: the symmetric case (6 design parameters) with the symmetric constraint on the support locations imposed, and the asymmetric case (12 design parameters) without the constraint imposed. Finally, verification experiments are performed on the two PCBs supported by screws located at the optimal positions. Although relatively large differences between the calculated, optimized fundamental frequencies and the experimental values are observed, the experiments confirm a very significant improvement in frequency for both cases.

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