The Wear Model Parameters Research of Cone Ring Sliding Plate on Tire Segmented Mould

2012 ◽  
Vol 501 ◽  
pp. 427-430
Author(s):  
Hai Ming Hu ◽  
Xiao Bin Li ◽  
Zhong Ke Tian
Keyword(s):  
Model Parameters ◽  
Wear Depth ◽  
Wear Coefficient ◽  
Wear Model ◽  
The Future ◽  
Solid Foundation ◽  
Sliding Plate

This paper researched the mating surfaces between sliding plates on cone ring and segment holders and discussed vertical clearance between segments caused by wear. Relationships between wear depth and parameter a, b, c and wear coefficient K of Archard wear model were analyzed. This work laid a solid foundation for confirming these coefficients accurately in the future.

A Numerical Simulation of Fretting Wear considering the Dynamic Evolution of Debris for the Coated Contact Surface

2021 ◽  
pp. 1-49
Author(s):  
Li Xiao ◽  
Yingqiang Xu ◽  
Zhiyong Chen
Keyword(s):  
Fretting Wear ◽  
Contact Pair ◽  
Dynamic Evolution ◽  
Wear Depth ◽  
Wear Coefficient ◽  
Wear Model ◽  
Wear Process ◽  
Dlc Coating ◽  
Wear Life ◽  
Wear Calculation

Abstract In this paper, a multi-layer body model in which material properties and wear coefficient change with node coordinates is proposed, so that the wear profile is not restricted by the singularity of the interface of the coated contact pairs. The conversion rate of the adhered particles was obtained to describe the growth and expansion of the debris at the fretting interface based on experiments, and the wear model of coated contact pair considering the dynamic evolution of the debris layer was established. By comparing the previous experimental and computational results, the wear calculation method proposed in this paper is more reasonable to predict the wear profile of the coated contact pair. In addition, the influence of the debris layer on the wear depth, friction width, and contact pressure in the fretting process is analyzed, indicating that the existence of the debris layer can delay the wear process. Finally, the fretting wear life of the SCMV steel contact pair deposited with the W-DLC coating is estimated.

scholarly journals Simulation and Experimental Study on Wear of U-Shaped Rings of Power Connection Fittings under Strong Wind Environment

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 735
Author(s):  
Songchen Wang ◽  
Xianchen Yang ◽  
Xinmei Li ◽  
Cheng Chai ◽  
Gen Wang ◽  
...  
Keyword(s):  
Abrasive Wear ◽  
Adhesive Wear ◽  
Surface Hardness ◽  
Wear Depth ◽  
Strong Wind ◽  
Wear Model ◽  
Wind Environment ◽  
Simulation Results ◽  
Oxidation Wear ◽  
Good Agreement

The objective of this study was to investigate the wear characteristics of the U-shaped rings of power connection fittings, and to construct a wear failure prediction model of U-shaped rings in strong wind environments. First, the wear evolution and failure mechanism of U-shaped rings with different wear loads were studied by using a swinging wear tester. Then, based on the Archard wear model, the U-shaped ring wear was dynamically simulated in ABAQUS, via the Umeshmotion subroutine. The results indicated that the wear load has an important effect on the wear of the U-shaped ring. As the wear load increases, the surface hardness decreases, while plastic deformation layers increase. Furthermore, the wear mechanism transforms from adhesive wear, slight abrasive wear, and slight oxidation wear, to serious adhesive wear, abrasive wear, and oxidation wear with the increase of wear load. As plastic flow progresses, the dislocation density in ferrite increases, leading to dislocation plugs and cementite fractures. The simulation results of wear depth were in good agreement with the test value of, with an error of 1.56%.

scholarly journals Climate change impacts model parameter sensitivity – What does this mean for calibration?

2020 ◽  
Author(s):  
Lieke Anna Melsen ◽  
Björn Guse
Keyword(s):  
Climate Change ◽  
Climate Change Impacts ◽  
The United States ◽  
Parameter Sensitivity ◽  
Model Parameters ◽  
Hydrological Models ◽  
The Future ◽  
Influence Parameter ◽  
Sensitivity Changes ◽  
Sensitive Parameters

Abstract. Hydrological models are useful tools to explore the hydrological impact of climate change. Many of these models require calibration. A frequently employed strategy is to calibrate the five parameters that were found to be most relevant as identified in a sensitivity analysis. However, parameter sensitivity varies over climate, and therefore climate change could influence parameter sensitivity. In this study we explore the change in parameter sensitivity within a plausible climate change rate, and investigate if changes in sensitivity propagate into the calibration strategy. We employed three frequently used hydrological models (SAC, VIC, and HBV), and explored parameter sensitivity changes across 605 catchments in the United States by comparing a GCM-forced historical and future period. Consistent among all models is that the sensitivity of snow parameters decreases in the future. Which parameters increase in sensitivity is less consistent among the models. In 43 % to 49 % of the catchments, dependent on the model, at least one parameter changes in the future in the top-5 most sensitive parameters. The maximum number of changes in the parameter top-5 is two, in 2–4 % of the investigated catchments. The value of the parameters that enter the top-5 cannot easily be identified based on historical data, because the model is not yet sensitive to these parameters. This requires an adapted calibration strategy for long-term projections, for which we provide several suggestions. The disagreement among the models on processes becoming relevant in future projections also calls for a strict evaluation of the adequacy of the model structure and the model parameters implemented therein.

Development and application of hyperelastic model for diaphragm considering the influence of temperature

2019 ◽  
Vol 08 (03) ◽  
pp. 1950010
Author(s):  
Lidong Wang ◽  
Xiongqi Peng ◽  
Mingrui Liu
Keyword(s):  
Constitutive Model ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Model Parameters ◽  
Influence Of Temperature ◽  
Nonlinear Fitting ◽  
Element Simulation ◽  
Hyperelastic Model ◽  
User Material Subroutine ◽  
Solid Foundation

The basic mechanical properties of a diaphragm under various temperatures in hot diaphragm preforming of composites are obtained by uniaxial tensile tests. A constitutive model considering the influence of temperature is accordingly developed to characterize its large deformation behavior. Model parameters are obtained by nonlinear fitting experiment data. The constitutive model is implemented in ABAQUS through the user material subroutine UHYPER. The developed constitutive model is verified by simulating the covering deformation of the diaphragm over a C-type mold. Finally, as an application of the developed hyperelastic model, an optimal design of a support bar in the hot diaphragm preforming process is implemented. The constitutive model lays a solid foundation for the finite element simulation and process optimization of the hot diaphragm forming (HDF) of carbon composites.

scholarly journals Creating a Solid Foundation for the Future

2019 ◽  
Vol 35 (1) ◽  
pp. 6-6
Author(s):  
Helge Seetzen
Keyword(s):  
The Future ◽  
Solid Foundation

Dynamic Analysis and Wear Prediction of Planar Five-Bar Mechanism Considering Multiflexible Links and Multiclearance Joints

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Gengxiang Wang ◽  
Hongzhao Liu
Keyword(s):  
Contact Force ◽  
Dynamic Performance ◽  
Contact Forces ◽  
Force Model ◽  
Displacement Curve ◽  
Wear Depth ◽  
Wear Model ◽  
Clearance Joint ◽  
Contact Force Model ◽  
Cylindrical Joint

Effects of wear and member flexibility on the dynamic performance of a planar five-bar mechanism with joint-clearance are investigated. The equation of motion of the mechanism is derived based on the absolute nodal coordinate formulation (ANCF). In order to enhance the accuracy of the contact force, the slope of the load–displacement curve of the cylindrical joint with clearance is used. The contact deformation couples the joint wear to the contact state. The contact force model of Flores and coworkers is improved, by the introduction of the stiffness coefficient. The wear depth is predicted by using the Archard's wear model. Simulations show that the multiclearance joints can generate stronger contact forces relative to single clearance joint case. This leads to more severe wear in the joint. However, the mechanism with multiple flexible links can absorb more of the energy arising from the clearance joint, and this improves the wear phenomenon.

scholarly journals Modelling the future evolution of glaciers in the European Alps under the EURO-CORDEX RCM ensemble

2018 ◽  
Author(s):  
Harry Zekollari ◽  
Matthias Huss ◽  
Daniel Farinotti
Keyword(s):  
Mass Balance ◽  
Climate Model ◽  
Model Parameters ◽  
Surface Mass Balance ◽  
European Alps ◽  
Ice Dynamics ◽  
Ice Flow ◽  
Surface Mass ◽  
Future Evolution ◽  
The Future

Abstract. Glaciers in the European Alps play an important role in the hydrological cycle, act as a source for hydroelectricity and have a large touristic importance. The future evolution of these glaciers is driven by surface mass balance and ice flow processes, which the latter is to date not included in regional glacier projections for the Alps. Here, we model the future evolution of glaciers in the European Alps with GloGEMflow, an extended version of the Global Glacier Evolution Model (GloGEM), in which both surface mass balance and ice flow are explicitly accounted for. The mass balance model is calibrated with glacier-specific geodetic mass balances, and forced with high-resolution regional climate model (RCM) simulations from the EURO-CORDEX ensemble. The evolution of the total glacier volume in the coming decades is relatively similar under the various representative concentrations pathways (RCP2.6, 4.5 and 8.5), with volume losses of about 47–52 % in 2050 with respect to 2017. We find that under RCP2.6, the ice loss in the second part of the 21st century is relatively limited and that about one-third (36.8 % ± 11.1 %) of the present-day (2017) ice volume will still present in 2100. Under a strong warming (RCP8.5) the future evolution of the glaciers is dictated by a substantial increase in surface melt, and glaciers are projected to largely disappear by 2100 (94.4 ± 4.4 % volume loss vs. 2017). For a given RCP, differences in future changes are mainly determined by the driving global climate model, rather than by the RCM that is coupled to it, and these differences are larger than those arising from various model parameters. We find that under a limited warming, the inclusion of ice dynamics reduces the projected mass loss and that this effect increases with the glacier elevation range, implying that the inclusion of ice dynamics is likely to be important for global glacier evolution projections.

scholarly journals Początki ruchu demokratycznego w Chińskiej Republice Ludowej (1976-1981)

2018 ◽  
pp. 141-153
Author(s):  
Jakub Bartolik
Keyword(s):  
Free Speech ◽  
Prime Minister ◽  
Democratic Movement ◽  
The Future ◽  
Solid Foundation

China is an emerging superpower. Its economical strength contrasts the lack of free speech and other liberties crucial for a prosperous economy. The democratic opposition is almost in its demise and society has little interest in politics. However, it hasn’t always been like that. This paper shows how the democratic movement emerged and it has developed since the mourning over the death of prime minister Zhou Enlai in 1976 during the Qing Ming, or the Tomb Sweeping festival. It also focuses on the intellectual turmoil of the Wall of Democracy in 1978, where some of the most important dissidents were published. This Chinese Hyde Park was officially closed in 1979 as the wave of repressions hit the dissidents. That event became a solid foundation for the future democratic opposition.

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