Optimum Positioning of Tank Mountings in a Fixed Tank Vehicle

Volume 2 ◽  
2004 ◽  
Author(s):  
Dimitris Koulocheris ◽  
Vasilis Dertimanis ◽  
Constantinos Spentzas
Keyword(s):  
Degrees Of Freedom ◽  
Rotational Acceleration ◽  
Six Degrees Of Freedom ◽  
Car Model ◽  
Damping Characteristics ◽  
Geometrical Constraints ◽  
Critical Characteristics ◽  
Stiffness And Damping ◽  
Quasi Newton ◽  
Newton's Methods

This paper aims at optimizing some critical characteristics of a fixed-tank biaxial vehicle, with respect to the lateral performance of the installed tank. For the description of the fixed-tank vehicle, a linear half car model with six degrees of freedom is implemented, subject to many types of road irregularities. The relative position of the tank mountings, with respect to the vehicle frame, as well as their corresponding stiffness and damping characteristics are optimized, such that the maximum values of vertical and rotational acceleration of the tank are minimized, under the geometrical constraints of the vehicle. For the optimization tasks, the BFGS quasi-Newton and the (μ+λ)-Evolution Strategy methods have been implemented. The former outperforms conventional Newton’s methods, due to the secant approximation of the Hessian, while the latter has been shown to perform better in many engineering applications, compared to other categories of EA.

Comparative Study of the Linear and Non-Linear Locomotive Response

1979 ◽  
Vol 101 (3) ◽  
pp. 263-271 ◽  
Author(s):  
E. H. Chang ◽  
V. K. Garg ◽  
C. H. Goodspeed ◽  
S. P. Singh
Keyword(s):  
Dynamic Response ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Design Parameters ◽  
Suspension Systems ◽  
Damping Characteristics ◽  
Time Histories ◽  
Steady State Responses ◽  
Stiffness And Damping ◽  
State Responses

A mathematical model for a six-axle locomotive is developed to investigate its dynamic response on tangent track due to vertical and/or lateral track irregularities. The model represents the locomotive as a system of thirty-nine degrees of freedom. The nonlinearities considered in the model are primarily associated with stiffness and damping characteristics of the primary suspension system. The transient and steady-state responses of the locomotive are obtained for the linear and nonlinear primary suspension systems. The response time-histories of the locomotive obtained by integrating the generalized equations of motion are presented. The potential uses of the model are indicated for studying the influence of different design parameters and predicting subsequent dynamic response.

scholarly journals Investigations of the static and dynamic characteristics of the precision hydrostatic spindle with mid-thrust bearing under different loads

2021 ◽  
pp. 135065012110236
Author(s):  
Chenggang Fang ◽  
Wucheng You ◽  
Dehong Huo
Keyword(s):  
Working Conditions ◽  
Dynamic Characteristics ◽  
Degrees Of Freedom ◽  
Thrust Bearing ◽  
Finite Difference Methods ◽  
Distribution Functions ◽  
Transient Pressure ◽  
Static And Dynamic Characteristics ◽  
Damping Characteristics ◽  
Stiffness And Damping

This paper investigates the static and dynamic characteristics of the precision hydrostatic spindle with a mid-thrust bearing under different working conditions. Firstly, the paper establishes the fluid governing equations of the coupled journal and thrust bearings based on orifice restrictors; and the dynamic and static Reynolds equations are solved using the perturbation and finite difference methods to obtain the steady and transient pressure distribution functions. Then the stiffness and damping characteristics of matrixes of the spindle are obtained by integrating the steady and transient pressure. Furthermore, by establishing the motion equation for the spindle rotor with five degrees of freedom, the quasi-static equilibrium position and stability criterion of the rotor under different working conditions are determined. Finally, the relationships between the dynamic and static characteristics of the spindle and cutting force, rotational speed, and cutting distance are simulated and analyzed. The simulation results show the patterns of variation in performance indices such as stiffness, damping, quasi-static position, and stability of the spindle under different working conditions, which provides important design information to be taken into consideration concerning the precision hydrostatic spindle.

scholarly journals A Class of Wavelet-Based Rayleigh-Euler Beam Element for Analyzing Rotating Shafts

2011 ◽  
Vol 18 (3) ◽  
pp. 447-458 ◽  
Author(s):  
Jiawei Xiang ◽  
Zhansi Jiang ◽  
Xuefeng Chen
Keyword(s):  
Degrees Of Freedom ◽  
Beam Element ◽  
Rotating Beam ◽  
Euler Beam ◽  
Boundary Node ◽  
Six Degrees Of Freedom ◽  
Spline Wavelets ◽  
Rotating Shafts ◽  
Wavelets On The Interval ◽  
Stiffness And Damping

A class of wavelet-based Rayleigh-Euler rotating beam element using B-spline wavelets on the interval (BSWI) is developed to analyze rotor-bearing system. The effects of translational and rotary inertia, torsion moment, axial displacement, cross-coupled stiffness and damping coefficients of bearings, hysteric and viscous internal damping, gyroscopic moments and bending deformation of the system are included in the computational model. In order to get a generalized formulation of wavelet-based element, each boundary node is collocated six degrees of freedom (DOFs): three translations and three rotations; whereas, each inner node has only three translations. Typical numerical examples are presented to show the accuracy and efficiency of the presented method.

Control of processing at multi-tool two-support setup

2020 ◽  
pp. 67-73
Author(s):  
N.D. YUsubov ◽  
G.M. Abbasova
Keyword(s):  
Degrees Of Freedom ◽  
Factor Model ◽  
Angular Displacement ◽  
Factor Models ◽  
Technological System ◽  
Displacement Control ◽  
Model Accuracy ◽  
Six Degrees Of Freedom ◽  
Angular Displacements ◽  
And Control

The accuracy of two-tool machining on automatic lathes is analyzed. Full-factor models of distortions and scattering fields of the performed dimensions, taking into account the flexibility of the technological system on six degrees of freedom, i. e. angular displacements in the technological system, were used in the research. Possibilities of design and control of two-tool adjustment are considered. Keywords turning processing, cutting mode, two-tool setup, full-factor model, accuracy, angular displacement, control, calculation [email protected]

scholarly journals Design and Calibration of a Hall Effect System for Measurement of Six-Degree-of-Freedom Motion within a Stacked Column

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3740
Author(s):  
Olafur Oddbjornsson ◽  
Panos Kloukinas ◽  
Tansu Gokce ◽  
Kate Bourne ◽  
Tony Horseman ◽  
...  
Keyword(s):  
Hall Effect ◽  
Degrees Of Freedom ◽  
Reactor Core ◽  
Degree Of Freedom ◽  
Life Extension ◽  
Scale Model ◽  
Design Development ◽  
Seismic Safety ◽  
Six Degrees Of Freedom ◽  
Six Degree Of Freedom

This paper presents the design, development and evaluation of a unique non-contact instrumentation system that can accurately measure the interface displacement between two rigid components in six degrees of freedom. The system was developed to allow measurement of the relative displacements between interfaces within a stacked column of brick-like components, with an accuracy of 0.05 mm and 0.1 degrees. The columns comprised up to 14 components, with each component being a scale model of a graphite brick within an Advanced Gas-cooled Reactor core. A set of 585 of these columns makes up the Multi Layer Array, which was designed to investigate the response of the reactor core to seismic inputs, with excitation levels up to 1 g from 0 to 100 Hz. The nature of the application required a compact and robust design capable of accurately recording fully coupled motion in all six degrees of freedom during dynamic testing. The novel design implemented 12 Hall effect sensors with a calibration procedure based on system identification techniques. The measurement uncertainty was ±0.050 mm for displacement and ±0.052 degrees for rotation, and the system can tolerate loss of data from two sensors with the uncertainly increasing to only 0.061 mm in translation and 0.088 degrees in rotation. The system has been deployed in a research programme that has enabled EDF to present seismic safety cases to the Office for Nuclear Regulation, resulting in life extension approvals for several reactors. The measurement system developed could be readily applied to other situations where the imposed level of stress at the interface causes negligible material strain, and accurate non-contact six-degree-of-freedom interface measurement is required.

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