Bridge Surface Roughness Detection Based on Double-Vehicle-Double-Pass Technique

2018 ◽  
Author(s):  
Ying Zhan
Keyword(s):  
Surface Roughness ◽  
Measured Data ◽  
Traffic Load ◽  
Double Pass ◽  
Bridge Monitoring ◽  
Roughness Profile ◽  
Element Simulation ◽  
Acceleration Data ◽  
Tire Wear ◽  
Wear And Tear

Bridge surface roughness encompasses dents, cracks, bulges and other defects due to construction as well as wear and tear in service. It significantly affects the traffic load on bridge, costs extra vehicle fuel consumption and tire wear, and therefore is a major concern of bridge monitoring and maintenance. As it considerably affects the contact force between the vehicle and the bridge, it is also a major obstacle of using vehicle measured data to identify bridge parameters. This paper presents a method to estimate the surface roughness profile of a bridge. With the acceleration data gathered from two different vehicles running on the bridge successively at the same speed, the roughness profile of the bridge can be measured with satisfactory accuracy. The method is verified with finite element simulation.

Bridge Surface Roughness Identification Based on Vehicle–Bridge Interaction

2019 ◽  
Vol 19 (07) ◽  
pp. 1950069 ◽  
Author(s):  
Y. Zhan ◽  
F. T. K. Au
Keyword(s):  
Surface Roughness ◽  
Structural Damage ◽  
Mass Model ◽  
Moving Vehicle ◽  
Roughness Profile ◽  
Element Simulation ◽  
Added Masses ◽  
Road Surface Roughness ◽  
Parameters Measurement ◽  
Error Indicators

As the surface roughness of a bridge has significant influence on the interaction between a moving vehicle and the bridge itself, it is one of the hurdles for the use of the drive-by technique in the assessment of bridges. Proper identification of the surface roughness of a bridge will help minimize the associated uncertainties and improve the accuracy of numerical simulation. This paper presents a method for estimating the surface roughness profile from the responses extracted from a vehicle instrumented with accelerometers passing on the bridge tested. By letting the vehicle run along the bridge multiple times with different added masses, an estimation of the roughness profile can be obtained based on the vehicle–bridge interaction theory. No baseline data is required. Three simplified vehicle models have been used in this study, i.e. spring–mass model, spring–damper–mass model and half-vehicle model. The feasibility and effectiveness of this method are evaluated by finite element simulation with a simply supported bridge and a continuous bridge. The performance of this method for different levels of road surface roughness is assessed by suitable error indicators. A parametric study about the influence of vehicle and bridge parameters, measurement noise and structural damage on the identified results have been carried out.

Calibration of Mobility and Interface Trap Parameters for High Temperature TCAD Simulation of 4H-SiC VDMOSFETs

2012 ◽  
Vol 717-720 ◽  
pp. 1101-1104 ◽  
Author(s):  
M.G. Jaikumar ◽  
Shreepad Karmalkar
Keyword(s):  
Surface Roughness ◽  
Measured Data ◽  
Interface Trap Density ◽  
Interface Trap ◽  
Material Parameters ◽  
Velocity Saturation ◽  
Physical Mechanisms ◽  
Surface Roughness Scattering ◽  
Wide Range ◽  
Tcad Simulation

4H-Silicon Carbide VDMOSFET is simulated using the Sentaurus TCAD package of Synopsys. The simulator is calibrated against measured data for a wide range of bias conditions and temperature. Material parameters of 4H-SiC are taken from literature and used in the available silicon models of the simulator. The empirical parameters are adjusted to get a good fit between the simulated curves and measured data. The simulation incorporates the bias and temperature dependence of important physical mechanisms like interface trap density, coulombic interface trap scattering, surface roughness scattering and velocity saturation.

Research on Surface Roughness of Supersonic Vibration Auxiliary Side Milling for Titanium Alloy

2021 ◽  
Author(s):  
XueTao Wei ◽  
caixue yue ◽  
DeSheng Hu ◽  
XianLi Liu ◽  
YunPeng Ding ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Prediction Model ◽  
Simulation Model ◽  
Finite Element Simulation ◽  
Simulation Software ◽  
Surface Roughness Prediction ◽  
Contour Shape ◽  
Element Simulation ◽  
Roughness Prediction

Abstract The processed surface contour shape is extracted with the finite element simulation software, and the difference value of contour shape change is used as the parameters of balancing surface roughness to construct the infinitesimal element cutting finite element model of supersonic vibration milling in cutting stability domain. The surface roughness trial scheme is designed in the central composite test design method to analyze the surface roughness test result in the response surface methodology. The surface roughness prediction model is established and optimized. Finally, the finite element simulation model and surface roughness prediction model are verified and analyzed through experiment. The research results show that, compared with the experiment results, the maximum error of finite element simulation model and surface roughness prediction model is 30.9% and12.3%, respectively. So, the model in this paper is accurate and will provide the theoretical basis for optimization study of auxiliary milling process of supersonic vibration.

Lastannahmen im Brückenbau – Vergleich von Verkehrslasten für Eisenbahnbrücken aus Lastmodellen und Messdaten/Actions on bridges – A comparison of traffic loads for railway bridges from traffic load models and measured data

Bauingenieur ◽  
2016 ◽  
Vol 91 (10) ◽  
pp. 410-416
Author(s):  
Gerhard Lener ◽  
Johannes Schmid
Keyword(s):  
Measured Data ◽  
Traffic Load ◽  
Railway Bridges ◽  
Load Models ◽  
Traffic Loads

Sowohl bei der ursprünglichen Dimensionierung als auch bei allfälligen Sanierungsvorhaben bedingen die Einwirkungen aus Verkehrslasten die Bauteilabmessungen maßgeblich. In vielen Fällen sind ältere Tragwerke nach heutigen Bemessungsrichtlinien deutlich unterdimensioniert, wodurch im Falle von Erweiterungsmaßnahmen zusätzliche Verstärkungsmaßnahmen im Bestand anfallen. Des Weiteren ist die Beurteilung der Restlebensdauer solcher Tragwerke in der Praxis schwierig, da in der Regel keine Informationen hinsichtlich der realen Einwirkungen aus Verkehrslasten vorhanden sind. Durch diesen unbefriedigenden Zustand motiviert, erfolgt in diesem Beitrag eine nähere Untersuchung realer, messtechnisch erfasster Einwirkungen auf Eisenbahnbrücken. Diese bilden die Basis für Vergleiche der Auswirkungen realer Messdaten und normativen Lastmodellen, die rechnerisch an unterschiedlichen Tragsystemen gezeigt werden. Dabei sind die im Vergleich zu den genormten Belastungen doch maßgeblich geringeren Einwirkungen deutlich erkennbar und liefern damit möglicherweise die Antwort auf die Frage, warum einzelne Eisenbahnbrücken nach wie vor funktionieren, obwohl deren rechnerische Lebensdauer bereits erreicht ist. Des Weiteren zeigt sich das daraus resultierende Optimierungspotenzial bei der Aktivierung von Realtragreserven beziehungsweise der deutlich höherer anzusetzender Lebenserwartung bestehender Tragwerke.

Numerical Simulation of Pressure Loss and Heat Transfer Characteristics for Additively Manufactured Channels

2020 ◽  
Author(s):  
Bryan Arko ◽  
Chad Iverson ◽  
Nicholas Staudigel
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Surface Roughness ◽  
Nusselt Number ◽  
Pressure Loss ◽  
Reynolds Numbers ◽  
Measured Data ◽  
Transfer Effects ◽  
Micro Channels ◽  
Heat Transfer Effects

Abstract This body of work provides an initial study of modeling both surface roughness and heat transfer concurrently in a numerical simulation of micro-channels representative of those that might be found in a turbine cooling application. Increased use of additive manufacturing (AM) or 3D printing techniques for turbomachinery components enable the manufacture of complex features to achieve higher operational performance. Accurate modeling of flow losses and heat transfer effects are critical to designing parts which achieve optimal efficiency paired with durability. Surface finish is rougher with AM compared to more traditional manufacturing techniques; therefore enhancing the pressure loss and heat transfer effects. Proper implementation of surface roughness within the computational model and correct modeling of the near wall boundary mesh must be maintained to produce accurate results. This study focuses on the comparison of near wall mesh treatment coupled with surface roughness to determine a practice for obtaining accurate pressure loss and heat transfer within a cooling passage, as compared to measurements. Steady-state computational fluid dynamics (CFD) models consisting of a wind tunnel inlet nozzle and outlet diffuser, along with internal cooling passages represented using micro-channels, has been run for a range of Reynolds numbers and simulated roughness levels. Analysis of a baseline configuration with aerodynamically smooth walls is first compared to the measured data to verify the assumption of aerodynamically smooth walls. Surface roughness is then added to the channel walls, from published test coupon measurements, and compared to published experimental data for a range of Reynolds numbers. The metal surrounding the passages is also included as a conjugate heat transfer model providing heat addition to the fluid. Pressure loss and heat transfer is compared to the measured data as a friction factor and Nusselt number for the range of Reynolds numbers. Since surface roughness units and measurements vary, an effect of surface roughness values on pressure loss and heat transfer will also be investigated to determine the importance of using and converting to the correct units for the numerical model. This serves as a starting point for a guideline that will help when both heat transfer and surface roughness are included in a CFD model. Further study is recommended to understand the diminishing levels of increase in friction factor and Nusselt number observed as surface roughness was continually increased in the numerical simulation.

scholarly journals Reduction of Ejection Forces in Injection Molding by Applying Mechanically Post-Treated CrN and CrAlN PVD Films

2019 ◽  
Vol 3 (4) ◽  
pp. 88
Author(s):  
Tillmann ◽  
Stangier ◽  
Lopes Dias ◽  
Gelinski ◽  
Stanko ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Injection Molding ◽  
Post Treatment ◽  
Injection Mold ◽  
Relevant Aspect ◽  
Production Rates ◽  
Surface Conditions ◽  
Roughness Profile ◽  
Coated Surfaces

In injection molding, the reduction of ejection forces is a process relevant aspect to improve the production rates. For this purpose, CrN and CrAlN films were sputtered on cylindrical and quadratic AISI H11 cores of an injection mold in order to investigate their influence on the resulting ejection forces to demold polypropylene test components. Within this context, the ejection forces of the PVD coated cores were compared to those of uncoated cores made of AISI H11. For both the cylindrical and quadratic cores, the as-deposited CrN and CrAlN films exhibit higher ejection forces than the uncoated cores due to the increase of the roughness profile after sputtering. It is known that the ejection forces are directly related to the surface roughness. In order to ensure comparable surface conditions to the uncoated surfaces, and to demonstrate the potential of PVD coated mold surfaces when reducing the ejection forces, the coated surfaces were mechanically post-treated to obtain a similar roughness profile as the uncoated cores. The combination of a PVD deposition and post-treatment ensures a significant reduction of the ejection forces by 22.6% and 23.7% for both core geometries.

Analysis of Surface Roughness Transformation of Oxide Scale during Hot Steel Manufacturing

2010 ◽  
Vol 126-128 ◽  
pp. 987-992
Author(s):  
Zheng Yi Jiang ◽  
Jian Ning Tang ◽  
A. Kiet Tieu ◽  
Wei Hua Sun ◽  
Dong Bin Wei
Keyword(s):  
Surface Roughness ◽  
Oxide Scale ◽  
Measured Data ◽  
Initial Surface ◽  
Surface Asperity ◽  
Decrease Rate ◽  
Steel Manufacturing ◽  
Simulation Results ◽  
Scale Surface

In this paper, the effects of the surface asperity wavelength, reduction and lubrication (friction) on the surface roughness transformation of the oxide scale have been studied. The simulation results show that the oxide scale surface roughness decreases with an increase of the average asperity wavelength and reduction. The initial surface roughness affects the decrease rate of surface roughness when the reduction increases. The surface roughness of the oxide scale and steel is quite close when the rolling with lubrication and both of them are reduced with reduction, and the surface roughness of the oxide scale is reduced less comparing with that of without lubrication case. The calculated roughness is close to the measured data.

scholarly journals Study of Wire Deformation Characterization and Size Effects during the Micro-Flat-Rolling Process

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 405 ◽  
Author(s):  
Haibo Xie ◽  
Ken-ichi Manabe ◽  
Zhengyi Jiang
Keyword(s):  
Surface Roughness ◽  
Contact Area ◽  
Rolling Process ◽  
Lateral Spread ◽  
Curvature Radius ◽  
Element Simulation ◽  
Flat Rolling ◽  
Set Up ◽  
Rolling Deformation

A comprehensive research on the flat rolling deformation characterization of microwire has been conducted systematically through finite element simulation and testified by the results from the experimental analysis. The obtained results are compared in terms of lateral spread, geometrical characteristic, contact area width and surface roughness considering the effects of pass reduction and initial wire diameter. The size effect has been identified and surface layer modeling has been set up based on surface grain share and grain size distribution. The numerical method combined with varied flow stress has been verified by experimental value with a maximum difference of 3.7% for the 1.5 mm wire. With the increase of the height reduction, the curvature radius is decreased while the lateral spread and contact area width are increased. Surface roughness evolution in the range of 0.52–0.85 µm for the rolled wire has also been investigated.

In Vitro Evaluation of Surface Properties and Wear Resistance of Conventional and Bulk-fill Resin-based Composites After Brushing With a Dentifrice

2019 ◽  
Vol 44 (6) ◽  
pp. 637-647 ◽  
Author(s):  
CAK Shimokawa ◽  
M Giannini ◽  
CB André ◽  
BO Sahadi ◽  
JJ Faraoni ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Three Dimensional ◽  
Significant Negative Correlation ◽  
Weak Correlation ◽  
Surface Loss ◽  
Roughness Profile ◽  
Before And After ◽  
Post Hoc

SUMMARY Objectives: This study evaluated the effect of toothbrushing with a dentifrice on gloss, roughness profile, surface roughness, and wear of conventional and bulk-fill resin-based composites. Methods and Materials: Gloss and surface roughness of resin-based composites (RBCs; Admira Fusion X-tra, Aura Bulk Fill, Filtek Bulk Fill Flowable, Filtek Bulk Fill Posterior Restorative, Filtek Supreme Ultra, Herculite Ultra, Mosaic Enamel, SDR flow+, Sonic Fill 2, Tetric EvoFlow Bulk Fill and Tetric EvoCeram Bulk Fill) were analyzed before and after brushing; the roughness profile and wear were also determined after toothbrushing. Representative three-dimensional images of the surface loss and images comparing the unbrushed and brushed surfaces were also compared. Analysis of variance and Tukey post hoc tests were applied (α=0.05) to the gloss, surface roughness, roughness profile, and surface loss data. Pearson's correlation test was used to determine the correlation between gloss and surface roughness, surface loss and percentage of gloss decrease after brushing, and surface loss and surface roughness after brushing. Results: For all RBCs tested after 20,000 brushing cycles, the gloss was reduced and the surface roughness increased (p<0.05). However, the roughness profile and the amount of surface loss were dependent on the RBC brand. Admira Fusion X-tra, Aura, Tetric EvoCeram Bulk Fill, and Tetric EvoFlow Bulk Fill showed the deepest areas of wear (p<0.05). A significant negative correlation was found between gloss and surface roughness, and a weak correlation was found between the decrease in gloss and the extent of surface loss, and any increase in surface roughness and the surface loss. Conclusions: Toothbrushing with a dentifrice reduced the gloss, increased the surface roughness, and caused loss at the surface of all the RBCs tested. Considering all the properties tested, Mosaic Enamel exhibited excellent gloss retention and a low roughness profile and wear, while Admira Fusion X-tra exhibited the greatest decrease in gloss, the highest roughness profile, and the most wear.

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