An investigation of the elastic cylindrical line contact equations for plane strain and stress considering friction

Author(s):  
Kefei Xu ◽  
Nolan R. Chu ◽  
Robert L. Jackson

This work presents a finite-element model-based study of elastic cylindrical contact. The aim is to evaluate the transition between the plane stress and plane strain-based Hertz solutions when each assumption is most applicable. To accomplish this, a range of curvatures, widths, Poisson’s ratios, and friction coefficients are considered. The finite-element model results for the elastic cylindrical contact cases are compared with the Hertz contact model when assuming plane stress or plane strain. Perhaps, surprisingly, the finite-element model predictions show little dependence on Poisson’s ratio and friction coefficient. The finite-element model predictions of force as a function of deflection agree relatively well with the plane stress Hertz prediction for all cases considered. The finite-element model predictions of contact width as a function of force actually fall below all the analytical Hertz predictions. Therefore, an adapted version of the Hertz equations is provided, which shows better agreement with the cases considered in this work.

Author(s):  
J P Domblesky ◽  
L Zhao

A study was conducted to assess the robustness of a plane strain finite element model that was developed to simulate plate shearing using the Cockroft-Latham fracture criterion and element deletion. Model predictions for blade gap, ductility and edge wear were compared with published experimental results. Results showed that the model was able to simulate initiation and propagation of fracture lines at the punch and die corners and the resultant break angle along the edge was found to be close to values observed in practice. Simulated edge geometry and microhardness were found to be in reasonable agreement with published experimental results for the steel plate considered although the model was unable to simulate double cutting at 0.8 per cent clearance. Results also suggest that edge hardness is independent of the starting ductility in the plate and that increasing the edge radii does not effectively simulate edge wear. Based on the results obtained, it may be concluded that the plane strain model is able to simulate plate shearing with sufficient accuracy in the range of normal process conditions.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
B. Asgari ◽  
S. A. Osman ◽  
A. Adnan

The model tuning through sensitivity analysis is a prominent procedure to assess the structural behavior and dynamic characteristics of cable-stayed bridges. Most of the previous sensitivity-based model tuning methods are automatic iterative processes; however, the results of recent studies show that the most reasonable results are achievable by applying the manual methods to update the analytical model of cable-stayed bridges. This paper presents a model updating algorithm for highly redundant cable-stayed bridges that can be used as an iterative manual procedure. The updating parameters are selected through the sensitivity analysis which helps to better understand the structural behavior of the bridge. The finite element model of Tatara Bridge is considered for the numerical studies. The results of the simulations indicate the efficiency and applicability of the presented manual tuning method for updating the finite element model of cable-stayed bridges. The new aspects regarding effective material and structural parameters and model tuning procedure presented in this paper will be useful for analyzing and model updating of cable-stayed bridges.


2001 ◽  
Author(s):  
Y. W. Kwon ◽  
J. A. Lobuono

Abstract The objective of this study is to develop a finite element model of the human thorax with a protective body armor system so that the model can adequately determine the thorax’s biodynamical response from a projectile impact. The finite element model of the human thorax consists of the thoracic skeleton, heart, lungs, major arteries, major veins, trachea, and bronchi. The finite element model of the human thorax is validated by comparing the model’s results to experimental data obtained from cadavers wearing a protective body armor system undergoing a projectile impact.


2021 ◽  
Author(s):  
Sandeep Dhar

The trajectory of an angular particle as it cuts a ductile target is, in general, complicated because of its dependence not only on particle shape, but also on particle orientation at the initial instant of impact. This orientation dependence has also made experimental measurement of impact parameters of single angular particles very difficult, resulting in a relatively small amount of available experimental data in the literature. The current work is focused on obtaining measurements of particle kinematics for comparison to rigid plastic model developed by Papini and Spelt. Fundamental mechanisms of material removal are identified, and measurements of rebound parameters and corresponding crater dimensions of single hardened steel particles launched against flat aluminium alloy targets are presented. Also a 2-D finite element model is developed and a dynamic analysis is performed to predict the erosion mechanism. Overall, a good agreement was found among the experimental results, rigid-plastic model predictions and finite element model predictions.


Author(s):  
V. Ramamurti ◽  
D. A. Subramani ◽  
K. Sridhara

Abstract Stress analysis and determination of eigen pairs of a typical turbocharger compressor impeller have been carried out using the concept of cyclic symmetry. A simplified model treating the blade and the hub as isolated elements has also been attempted. The limitations of the simplified model have been brought out. The results of the finite element model using the cyclic symmetric approach have been discussed.


2013 ◽  
Vol 671-674 ◽  
pp. 1012-1015
Author(s):  
Zhao Ning Zhang ◽  
Ke Xing Li

Due to the environment, climate, loads and other factors, the pre-stress applied to the beam is not a constant. It is important for engineers to track the state of the pre-stress in order to ensure security of the bridge in service. To solve the problem mentioned above, the paper puts forward a new way to analyze the effective pre-stress using the displacement inversion method based on the inversion theory according to the measured vertical deflection of the bridge in service at different time. The method is a feasible way to predict the effective pre-stress of the bridge in service. Lastly, taking the pre-stressed concrete continuous rigid frame bridge for example, the effective pre-stress is analyzed by establishing the finite element model.


Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3258 ◽  
Author(s):  
Valery Gupalov ◽  
Alexander Kukaev ◽  
Sergey Shevchenko ◽  
Egor Shalymov ◽  
Vladimir Venediktov

The paper considers the construction of a piezoelectric accelerometer capable of measuring constant linear acceleration. A number of designs are proposed that make it possible to achieve high sensitivity with small dimensions and a wide frequency band (from 10−5 Hz). The finite element model of the proposed design was investigated, and its output characteristic and scale factor (36 mV/g) were obtained.


2019 ◽  
Vol 71 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Shixian Xu ◽  
Zhengtao Su ◽  
Jian Wu

Purpose This paper aims to research the influence of pressure, friction factors, roughness and actuating speed to the mixed lubrication models of outstroke and instroke. Design/methodology/approach Mixed lubrication model is solved by finite volume method, which consists of coupled fluid mechanics, deformation mechanics and contact mechanics analyses. The influence of friction factor on the finite element model is also considered. Then, contact pressure, film thickness, friction and leakage have been studied. Findings It was found that the amount of leakage is sensitive to the film thickness. The larger the film thickness is, the greater the influence received from the friction factor, however, the effect of oil film on the friction is negligible. The friction is determined mainly by the contact pressure. The trend of friction and leakage influenced by actuating velocity and roughness is also obtained. Originality/value The influence of friction factor on the finite element model is considered. This can make the calculation more accurate.


2014 ◽  
Vol 6 (1) ◽  
pp. 19-25
Author(s):  
Gergely Máté Kiss ◽  
István Vajda

Abstract Co-simulation is a method which makes it possible to study the electric machine and its drive at once, as one system. By taking into account the actual inverter voltage waveforms in a finite element model instead of using only the fundamental, we are able to study the electrical machine's behavior in more realistic scenario. The recent increase in the use of variable speed drives justifies the research on such simulation techniques. In this paper we present the co-simulation of an inverter fed permanent magnet synchronous machine. The modelling method employs an analytical variable speed drive model and a finite element electrical machine model. By linking the analytical variable speed drive model together with a finite element model the complex simulation model enables the investigation of the electrical machine during actual operation. The methods are coupled via the results. This means that output of the finite element model serves as an input to the analytical model, and the output of the analytical model provides the input of the finite element model for a different simulation, thus enabling the finite element simulation of an inverter fed machine. The resulting speed and torque characteristics from the analytical model and the finite element model show a good agreement. The experiences with the co-simulation technique encourage further research and effort to improve the method.


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