Dynamic Model for Friction-Induced Oxidation of Metals in Dry Sliding Processes

2020 ◽  
Vol 143 (8) ◽  
Author(s):  
M. A. Valdés Canaval ◽  
L. M. Gómez ◽  
A. Toro ◽  
Cesar A. Isaza M. ◽  
J. S. Rudas
Keyword(s):  
Dynamic Model ◽  
Real Contact Area ◽  
Dry Sliding ◽  
Flash Temperature ◽  
Lumped Parameter ◽  
Proposed Model ◽  
Magnetite Fe3o4 ◽  
New Equation ◽  
Hematite Fe2o3 ◽  
Pin On Disk

Abstract Oxidative mechanisms in tribological processes are commonly related with temperature and the real contact area. In this article, a lumped parameter dynamic model was developed to predict friction-generated oxide thicknesses in dry sliding conditions. The proposed model is based on conservative principles and causal equations applied to a pin-on-disk configuration in order to calculate the flash temperature with base on the heat transfer phenomena. Also, a mass balance was proposed to estimate the amount of hematite (Fe2O3), magnetite (Fe3O4), and wüstite (FeO) formed by friction heat. A new equation was proposed to predict the thicknesses of the oxides generated, and the model was validated based on experimental data available in specialized literature.

Hybrid Dynamic Modeling and Analysis of High-speed Thin-rimmed Gears

2021 ◽  
pp. 1-23
Author(s):  
Changzhao Liu ◽  
Yu Zhao ◽  
Yong Wang ◽  
Tie Zhang ◽  
Hanjie Jia
Keyword(s):  
Finite Element ◽  
Dynamic Model ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Element Model ◽  
Lumped Parameter Model ◽  
Modeling And Analysis ◽  
Lumped Parameter ◽  
Proposed Model ◽  
Angular Displacements

Abstract In this study, a hybrid dynamic model of high-speed thin-rimmed gears is developed. In this model, the translational and angular displacements (including the rigid and vibration displacements) with a total of six degrees of freedom (DOFs) are selected as the generalized coordinates for each gear, and the meshing force distributions along the contact line and between the teeth are considered. Thus, the model can be implemented under stationary and non-stationary conditions. The condensed finite element models are developed with the centrifugal and inertia forces for gear bodies. This paper proposes a novel method to couple the lumped parameter model and condensed finite element model for the hybrid dynamic model system, which considers the variation of the meshing tooth during the gear operation, namely, the variations of the acting point of meshing force. Based on the model, the dynamic analysis of high-speed thin-rimmed gears is conducted under stationary speed and acceleration processes. The effects of the flexible gear body, high speed, and tooth errors on the system dynamics and tooth load distribution are investigated. The analysis results are also compared with the current reference and pure finite element method to validate the proposed model.

Heat resistance of coatings metal deposited by nickel-manganese-molybdenum fl ux-cored wire

2020 ◽  
pp. 511-515
Author(s):  
E.N. Eremin ◽  
A.S. Losev ◽  
I.A. Ponomarev ◽  
S.A. Borodikhin
Keyword(s):  
Heat Resistance ◽  
Elevated Temperatures ◽  
Mass Gain ◽  
Cored Wire ◽  
Protective Properties ◽  
Average Mass ◽  
Magnetite Fe3o4 ◽  
Hematite Fe2o3 ◽  
Nickel Manganese

The heat-resistance of coating from deposited steel 15N8G6M3FTB at temperature of 900 °С is studied. It is established that this dependence occurs in the first hours. The average mass gain of the metal scale of such coating at 900 °С is 0.0128 kg/(m2 •h). It is shown that the basis of metal scale of the composition 15N8G6M3FTB is hematite Fe2O3 and magnetite Fe3O4, as well as MnO, which have protective properties. The number of other phase compounds with high protective properties is negligible. The coating from steel 15N8G6M3FTB can be used for applying to the surface of parts operating at elevated temperatures.

Dynamics of the Gear Train Set in Wind Turbine

2011 ◽  
Vol 697-698 ◽  
pp. 701-705
Author(s):  
D.D. Ji ◽  
Y.M. Song ◽  
J. Zhang
Keyword(s):  
Wind Turbine ◽  
Dynamic Model ◽  
Harmonic Balance Method ◽  
Planetary Gear ◽  
Gear Train ◽  
Dynamic Responses ◽  
Multi Stage ◽  
Lumped Parameter ◽  
Cartesian Coordinate ◽  
The Impact

A lumped-parameter dynamic model for gear train set in wind turbine is proposed to investigate the dynamics of the speed-increasing gear box. The proposed model is developed in a universal Cartesian coordinate, which includes transversal and torsional deflections of each component, time-varying mesh stiffness, gear profile errors and external excitations. By solving the dynamic model, a modal analysis is performed. The results indicate that the modal properties of the multi-stage gear train in wind turbine are similar to those of a single-stage planetary gear set. A harmonic balance method (HBM) is used to obtain the dynamic responses of the gearing system. The responses give insight into the impact of excitations on the vibrations.

An analytical model for predicting the shear strength of unsaturated soils

2022 ◽  
pp. 1-57
Author(s):  
Tuan A. Pham ◽  
Melis Sutman
Keyword(s):  
Shear Strength ◽  
Analytical Model ◽  
Unsaturated Soils ◽  
High Performance ◽  
Micromechanical Model ◽  
Experimental Studies ◽  
Stress Equilibrium ◽  
Proposed Model ◽  
New Equation ◽  
Multi Phase

The prediction of shear strength for unsaturated soils remains to be a significant challenge due to their complex multi-phase nature. In this paper, a review of prior experimental studies is firstly carried out to present important pieces of evidence, limitations, and some design considerations. Next, an overview of the existing shear strength equations is summarized with a brief discussion. Then, a micromechanical model with stress equilibrium conditions and multi-phase interaction considerations is presented to provide a new equation for predicting the shear strength of unsaturated soils. The validity of the proposed model is examined for several published shear strength data of different soil types. It is observed that the shear strength predicted by the analytical model is in good agreement with the experimental data, and get high performance compared to the existing models. The evaluation of the outcomes with two criteria, using average relative error and the normalized sum of squared error, proved the effectiveness and validity of the proposed equation. Using the proposed equation, the nonlinear relationship between shear strength, saturation degree, volumetric water content, and matric suction are observed.

Novel investigation on tribological behavior of microwave synthesized functionally graded claddings

2021 ◽  
pp. 095440622110458
Author(s):  
Sarbjeet Kaushal ◽  
Dheeraj Gupta ◽  
Hiralal Bhowmick
Keyword(s):  
Functional Performance ◽  
Single Layer ◽  
Substrate Material ◽  
Functionally Graded ◽  
Dry Sliding Wear ◽  
Wear Loss ◽  
Dry Sliding ◽  
Maximum Value ◽  
Microhardness Profile ◽  
Pin On Disk

In this study, functional performance of Ni/Cr3C2 functionally graded claddings (FGCs) was investigated under dry sliding wear environment. The Ni/Cr3C2-based FGCs were produced by varying Cr3C2 fraction (Ni-XCr3C2) (X=10%–30% by weight) using microwave irradiation. The FGC layers were composed of cellular-structure with reinforced particles dispersed randomly inside Ni-based matrix. Variation of Cr3C2 particles inside Ni matrix exhibited significant impact on micro-structural and mechanical properties. The microhardness profile of the FGC layers showed an increase in hardness value with an increase in the amount of reinforced Cr3C2 particles. FGC top layers showed the maximum value of micro-hardness of 555 ± 34 HV. Functional performance of microwave processed FGCs was studied through the pin-on-disk tribometer under varying sliding velocity and sliding distances. For comprehension study, wear study was also carried out on microwave processed single layer clads with compositions corresponding to FGC layers. The FGC sample showed better wear resistance than all single clad layers and substrate material. The FGC sample exhibited 1.6 times less wear rate than the Ni-based + 30% Cr3C2 single layer clad. The worn-out surfaces of FGC and single-layer-clads showed presence of multiples cracks and grooves, which resulted in their weight loss during dry sliding contact. Material debonding and the formation of craters and cracks are the main phenomena responsible for the wear loss in the FGC surface.

A Lumped Parameter Electromechanical Model for Describing the Nonlinear Behavior of Piezoelectric Actuators

1997 ◽  
Vol 119 (3) ◽  
pp. 478-485 ◽  
Author(s):  
M. Goldfarb ◽  
N. Celanovic
Keyword(s):  
System Analysis ◽  
Nonlinear Behavior ◽  
Piezoelectric Actuators ◽  
Bond Graph ◽  
Lumped Parameter Model ◽  
Input Output ◽  
Mechanical Stiffness ◽  
Analysis And Design ◽  
Lumped Parameter ◽  
Proposed Model

A lumped-parameter model of a piezoelectric stack actuator has been developed to describe actuator behavior for purposes of control system analysis and design, and in particular for control applications requiring accurate position tracking performance. In addition to describing the input-output dynamic behavior, the proposed model explains aspects of nonintuitive behavioral phenomena evinced by piezoelectric actuators, such as the input-output rate-independent hysteresis and the change in mechanical stiffness that results from altering electrical load. Bond graph terminology is incorporated to facilitate the energy-based formulation of the actuator model. The authors propose a new bond graph element, the generalized Maxwell resistive capacitor, as a lumped-parameter causal representation of rate-independent hysteresis. Model formulation is validated by comparing results of numerical simulations to experimental data.

scholarly journals The Enhancement and Study of Sintering Time Effect Toward Content of Fe and Ti Compounds in Mineral Sand

2020 ◽  
Vol 9 (2) ◽  
pp. 55-58
Author(s):  
Fauzi Fauzi ◽  
Zulfalina Zulfalina
Keyword(s):  
Grain Size ◽  
Magnetic Separation ◽  
Raw Materials ◽  
Weight Fraction ◽  
Time Effect ◽  
Sintering Time ◽  
Magnetite Fe3o4 ◽  
Hematite Fe2o3 ◽  
Black Color

Pasir mineral merupakan salah satu mineral endapan (sedimen) dengan ukuran butir 0,074-5 mm, ukuran kasar (5–3 mm) dan halus (1 mm), ciri fisik dari pasir mineral ini diantaranya berwarna hitam dan cenderung tertarik oleh magnet. Berdasarkan beberapa penelitian yang telah dilakukan sebelumnya didapatkan bahwa kandungan utama dari pasir mineral berupa mineral ilmenit (FeTiO3), hematite (Fe2 - O3), dan magnetit (Fe3O4). Oleh karena itu maka pasir mineral ini sangat potensial untuk menghasilkan logam Fe, Ti, besi oksida dan pigmen titanium oksida. Dalam penelitian ini pengayaan kandungan besi dilakukan dengan metode separasi magnetik kemudian dikarakterisasi menggunakan XRF. Selanjutnya sampel tersebut disinter pada suhu 800oC, dengan variasi waktu penahanan selama 2, 4 dan 6 jam dan di karakterisasi menggunakan XRD, dimana hasilnya dianalisis dengan metode GSAS. Hasil pengujian XRF menunjukkan bahwa pasir mineral murni (bahan mentah) mempunyai kandungan Fe dan Ti masing–masing 14,38 dan 2,80% (%berat), sedangkan setelah separasi magnetik kandungan Fe dan Ti meningkat masing–masing menjadi 83,51 dan 7,25% (%berat). Hasil analisis GSAS menunjukkan bahwa waktu sintering berpengaruh terhadap fraksi berat Fe dan Ti, ini ditunjukkan senyawa Fe3O4 menurun dari 81,85 menjadi 77,76% dan Fe2O3 dari 11,44 menjadi 3,41%, sementara FeTiO3 meningkat dengan bertambahnya waktu sintering dari 6,72 menjadi 18,83%. The mineral sand is one of the mineral sediments with grain size of 0.074 – 5 mm, coarse size (5–3 mm) and fine (1 mm). The physical characteristics of this mineral sand are black color and tend to be attracted by magnets. Based on several studies, the main content of mineral sand is ilmenite (FeTiO3), hematite (Fe2O3), and magnetite (Fe3O4). Therefore mineral sand is very potential to produce Fe, Ti, iron oxide and titanium oxide pigments. In this study, the iron contents from raw materials were enhanced by magnetic separation method, and then the samples were characterized using XRF. Therefore they were sintered at temperature 800oC and variation of holding times 2, 4 and 6 h. The characterization of sample used XRD, where this result is analyzed using GSAS method. The XRF results showed that pure mineral sand (raw materials), has Fe and Ti contents of 14.38 and 2.80% (%weight), whereas after magnetic separation, the Fe and Ti contents increased to 83.51 and 7.25%, respectively. The analysis result of GSAS showed that the sintering time affected the weight fraction of Fe and Ti. These indicated that Fe3O4 decreased from 81.85 to 77.76% and Fe2O3 from 11.44 to 3.41%, while FeTiO3 raise with increasing of sintering time from 6.72 to 18.83%. Keywords: Enhancement, sintering time, compound content, mineral sand, GSAS

A mixed FEM and lumped-parameter dynamic model for evaluating the modal properties of planetary gearboxes

2018 ◽  
Vol 32 (7) ◽  
pp. 3047-3056 ◽  
Author(s):  
Franco Concli ◽  
Luca Cortese ◽  
Renato Vidoni ◽  
Filippo Nalli ◽  
Giovanni Carabin
Keyword(s):  
Dynamic Model ◽  
Modal Properties ◽  
Mixed Fem ◽  
Lumped Parameter

scholarly journals Vibration analysis of multi-body dynamic model of combat vehicle gearbox

2019 ◽  
Vol 287 ◽  
pp. 03005
Author(s):  
Jan Furch ◽  
Cao Vu Tran
Keyword(s):  
Dynamic Model ◽  
Vibration Signal ◽  
Technical Condition ◽  
Proposed Model ◽  
Combat Vehicle ◽  
Failure Conditions ◽  
The Individual ◽  
Multi Body ◽  
Material Wear ◽  
Body Dynamic

The combat vehicle gearbox, during the operation, generates vibration signals being related to the technical condition of gearbox. The analysis of the vibration signal could be used to determine accurately the behaviour of gearbox. Along with the development of the computer technology, the multi-body dynamic solution has been used widely to simulate, analyse, and determine the technical condition of gearbox. The purpose of this paper is to introduce the dynamic model of combat vehicle gearbox, and the simulation process based on the multi-body dynamic software, namely MSC.ADAMS. This proposed model allows the detection of failure conditions of individual gears and bearings in the gearbox. In this way, the fault conditions of the individual transmission components are identified. In the future, we would like to include a material wear module in the model, and we would like to model the life of the gearbox. We assume that we would also carry out accelerated tests of the gearbox to verify validity.

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