A MATHEMATICAL MODEL FOR ANALYZING THE INFLUENCE OF SHAPE DEVIATIONS AND MOUNTING ERRORS ON GEAR DYNAMIC BEHAVIOUR

1996 ◽  
Vol 191 (5) ◽  
pp. 629-660 ◽  
Author(s):  
P. Velex ◽  
M. Maatar
Keyword(s):  
Mathematical Model ◽  
Dynamic Behaviour ◽  
Shape Deviations

The static and dynamic characteristics of a pressure relief valve with a proportional solenoid-controlled pilot stage

2002 ◽  
Vol 216 (2) ◽  
pp. 143-156 ◽  
Author(s):  
R Maiti ◽  
R Saha ◽  
J Watton
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Dynamic Behaviour ◽  
Practical Experience ◽  
Pressure Relief Valve ◽  
Relief Valve ◽  
Pressure Relief ◽  
Static And Dynamic Characteristics ◽  
Good Comparison ◽  
The Mathematical Model

The steady state and dynamic characteristics of a two-stage pressure relief valve with proportional solenoid control of the pilot stage is studied theoretically as well as experimentally. The mathematical model is studied within the MATLAB-SIMULINK environment and the non-linearities have been considered via the use of appropriate SIMULINK blocks. The detailed modelling has resulted in a good comparison between simulation and measurement, albeit assumptions had to be made regarding the solenoid dynamic characteristic based upon practical experience. The use of this characteristic combined with additional dynamic terms not previously considered allows new estimations of internal characteristics to be made such as the damping flowrate. The overall dynamic behaviour has been shown to be dominated by the solenoid characteristic relating force to applied voltage.

scholarly journals Bondgraph modelling and simulation of the dynamic behaviour of above-knee prostheses

1987 ◽  
Vol 11 (2) ◽  
pp. 65-70 ◽  
Author(s):  
P. G. Van De Veen ◽  
W. Van Der Tempel ◽  
J. De Vreiss
Keyword(s):  
Mathematical Model ◽  
Computer Simulation ◽  
Mass Distribution ◽  
Total Mass ◽  
Dynamic Behaviour ◽  
Step Length ◽  
Swing Phase ◽  
Knee Prostheses ◽  
Prosthetic Foot ◽  
Walking Velocity

A mathematical model was used to investigate the dynamic behaviour of an above-knee (AK) prosthesis in the swing phase and to analyse the influence of mass and mass distribution on the maximal stump load and the required energy. The model consists of a bondgraph model of the prosthesis and a “walking” model which predicts the walking velocity, step length and the femoral trajectory. Equipment was developed to measure the inertial properties of the components of the prosthesis. Through computer simulation, stickdiagrams of the swing phase and graphs of the variation with time of the hip and stump forces were obtained. It was found that for a normal AK prosthesis with a knee-lock mechanism the axial stump load is greatest at the beginning and at the end of the swing phase. At a walking velocity of 5 km/hr the maximum axial stump load amounts to 2.1 times the static weight of the prosthesis. The maximum axial stump force appeared to be almost directly proportional to the total mass of the prosthesis but independent of the mass distribution. The required energy also increased with the mass of the prosthesis but is' dependent on mass distribution. Because of their comparable weights the influence of the shoe is almost equal to the influence of the prosthetic foot. Thus lightweight shoes should be used with lightweight prosthetic feet in order to add to their advantages.

scholarly journals Investigation of Seismic Behavior of Container Crane Structures by Shake Table Tests and Mathematical Modeling

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
C. Oktay Azeloglu ◽  
Ayse Edincliler ◽  
Ahmet Sagirli
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Seismic Behavior ◽  
Dynamic Behaviour ◽  
Earthquake Ground Motion ◽  
Shake Table ◽  
Engineering Structures ◽  
Shake Table Tests ◽  
Container Cranes ◽  
Container Crane

This paper is concerned with the verification of mathematical modeling of the container cranes under earthquake loadings with shake table test results. Comparison of the shake table tests with the theoretical studies has an important role in the estimation of the seismic behavior of the engineering structures. For this purpose, a new shake table and mathematical model were developed. Firstly, a new physical model is directly fixed on the shake table and the seismic response of the container crane model against the past earthquake ground motion was measured. Secondly, a four degrees-of-freedom mathematical model is developed to understand the dynamic behaviour of cranes under the seismic loadings. The results of the verification study indicate that the developed mathematical model reasonably represents the dynamic behaviour of the crane structure both in time and frequency domains. The mathematical model can be used in active-passive vibration control studies to decrease structural vibrations on container cranes.

Studying Dynamic Behaviour of Flexible Rotors With an Analytic Model That Includes Non-Linear Supports, Non-Stiff Support Structure and Torsion Flexibility

2007 ◽  
Author(s):  
Heller G. Sa´nchez A. ◽  
Jesu´s M. Pintor B.
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Dynamic Behaviour ◽  
Mathematical Formulation ◽  
Model Parameters ◽  
Analytic Model ◽  
Support Structure ◽  
Stationary Response ◽  
Rigid Structure ◽  
Flexible Rotors

This article presents a mathematical formulation based on FEM for the dynamic analysis of flexible rotors that are not grounded necessary to a rigid structure. Furthermore, it uses the component synthesis in order to introduce the behavior of the structure where the rotor is grounded. The developed mathematical model calculates the model parameters stationary response.

scholarly journals Assessment of dynamic behaviour of earth dams taking into account large strains

2019 ◽  
Vol 97 ◽  
pp. 05019 ◽  
Author(s):  
Mirziyod Mirsaidov ◽  
Tokhirjon Sultanov ◽  
Javlon Yarashov ◽  
Elyor Toshmatov
Keyword(s):  
Mathematical Model ◽  
Dynamic Behavior ◽  
Geometric Nonlinearity ◽  
Dynamic Behaviour ◽  
Large Strains ◽  
Earth Dams ◽  
Kinematic Effect ◽  
Resonant Modes

This paper presents the results of the assessment and prediction of the dynamic behavior of earth dams of various heights, taking into account large strains (geometric nonlinearity) and inhomogeneous features of structures under multi-component kinematic effects. A mathematical model, methodology and algorithm for estimating dynamic behavior of earth dams taking into account inhomogeneous features of structures and large strains in spatial and plane statements are given. Dynamic behavior of the models of the Pachkamar, Gissarak and Nurek earth dams has been studied taking into account large strains and inhomogeneous features of structures in various pre-resonant and resonant modes under multi-component kinematic effect. A number of new effects associated with the manifestation of large strains in the structure under various dynamic influences are revealed.

scholarly journals MODELLING THE DYNAMIC BEHAVIOUR OF THE TRUCK-CRANE

Transport ◽  
2012 ◽  
Vol 26 (4) ◽  
pp. 410-417 ◽  
Author(s):  
Radomir Mijailović
Keyword(s):  
Mathematical Model ◽  
Dynamic Analysis ◽  
Dynamic Behaviour ◽  
Generalized Coordinates ◽  
Mechanical Models

The paper deals with the problem of a dynamic analysis of truck-cranes. Therefore, the article has developed a mechanical-mathematical model having 18 generalized coordinates. Depending on the type of truck crane operation as well as on the fact whether the aim of the article is to conduct the dynamic analysis of the whole truck crane or only that of one of its components, simpler mechanical models are also offered. The presented model is more realistic than those describing the dynamic behaviour of the truck-crane performing all necessary functions, i.e. a mobile means of lifting, transportation and reloading.

scholarly journals Mathematical model of the impact assessment of roughness and waviness deviations of races surfaces of rolling bearings on the level of generated vibration

Mechanik ◽  
2019 ◽  
Vol 92 (1) ◽  
pp. 35-37
Author(s):  
Paweł Zmarzły
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Impact Assessment ◽  
Ball Bearings ◽  
Vibration Level ◽  
Rolling Bearings ◽  
Shape Deviations ◽  
Specific Frequency ◽  
The Impact ◽  
Dominant Influence

The article presents mathematical models allowing to describe the level of vibration generated by ball bearings 6304-2z type depending on the value of roughness and waviness deviations of inner and outer bearings races. This models will allow to estimate what type of shape deviations have dominant influence on the vibration level generated in specific frequency ranges.

scholarly journals The improvement of bolted joints model via finite element model updating method

2021 ◽  
Vol 15 (4) ◽  
pp. 8635-8643
Author(s):  
M. A. Yunus ◽  
M.N. Abdul Rani ◽  
M.A.S. Aziz Shah ◽  
M.S.M. Sani ◽  
Z. Yahya
Keyword(s):  
Mathematical Model ◽  
Sheet Metal ◽  
Dynamic Behaviour ◽  
Model Updating ◽  
Thin Sheet ◽  
Local Deformation ◽  
Bolted Joints ◽  
Fe Model ◽  
Thin Sheet Metal ◽  
Fe Model Updating

Efficient schemes to represent mathematical model of thin-sheet metal structures jointed by bolted joints for accurately predict the structure dynamic behaviour has been a significant unresolved issue in structural dynamics community. The biggest challenge is to efficiently incorporate the joints local deformation effects on the developed mathematical model via finite element (FE) method. Generally, the joints local deformation typically exerts on the joints mating area. To solve this issue, this paper proposes efficient schemes to represent mathematical model of thin-sheet metal structures jointed by bolted joints with application to accurately calculate the structure dynamic behaviour using FE model updating method. The initial FE model of the assembled structure was developed by employed Fastener Connector (CFAST) in MSC NASTRAN software to represent the bolted joints while, the inclusion of the local deformation effects at the bolted joints mating area was represented by contact elements. Then, the responses obtained from the FE model was evaluated by weight up with experimental data. FE model updating (FEMU) method then was utilised for minimising prediction discrepancies originated from the initial FE model based on the experimental data. The proposed scheme shows the accuracy of the initial prediction was improved from 25.03 % to 14.65 %  while the accuracy of the predicted mode shapes via modal assurance criterion (MAC) analysis were above 0.8. Therefore, the findings offer useful schemes for improving the quality of predicted dynamic behaviour, particularly in the thin-sheet metal jointed structure and the developed model can be used with confident for any subsequence dynamic analyses.

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