Stress Gradient Determination in Anti-Corrosion Multilayer Coating
Pierre-Antoine DubosQuentin HattePascal CasariMireille Richard‐PlouetPierre-Yves JouanSamuel BranchuNadia Guitter
3
Citation
20
Reference
10
Related Paper
Citation Trend
Abstract:
To reduce maintenance and to increase the corrosion protection and lifetime of maritimestructures while complying with environmental standards, multilayer coatings are applied to protectsteel sections. A new generation of hybrid sol-gel and/or HiPIMS Ni-based thin films appear toconstitute an efficient pre-treatment before the anti-corrosion paint application. However, increasingthe number of coatings and associated interfaces may lead to coating failure due to stresses inducedby the different deposition processes. Therefore developing smart models to assess the stressdistribution along these multilayers appears of significant importance. The well-known Stoneyformula cannot be used for multilayers and owing to the large dimensions of the object to be protected.To assess an easily measurable curvature after deposition, thin steel sheets are used but do not respectany more the Stoney hypotheses. So we set up an analytical thermo-elasto-plastic model to evaluatethe stresses induced by depositions in each layer. This model is based on the various thermalexpansion coefficients of every coat. After extrapolation along the complete thickness, combiningsol-gel and PVD deposition smoothens the stress difference between steel and paint. The shearstresses at interface seems thus to be reduced. The evolution of the stress difference between layerswith the imposed deflection can predict the mechanical strength and the interface failure. In order toevaluate the quality of the model, in-situ four-point bending in SEM was performed to study of theadhesion between the various layers. The results deduced from the model are in good agreement withSEM images.Keywords:
Deposition
Delamination
Cite
Citations (123)
Linearity
Saturation (graph theory)
Cite
Citations (9)
Interval arithmetic
Cite
Citations (0)
The extrapolation of EM lifetimes obtained from high temperature tests to lower temperatures is investigated. It is shown that the usual extrapolation method leads to large errors for the predicted lifetimes at temperatures closer to the real operating conditions. A different approach for estimating the extrapolation parameters is discussed, where the results show significantly smaller errors. Thus, the reliability of interconnects regarding electromigration failures is more precisely assessed.
Electromigration
Cite
Citations (1)
Divergence (linguistics)
Richardson extrapolation
Cite
Citations (7)
Up to now, various TTP (time-temperature parameter) methods have been proposed to deter. mine creep-rupture strength by extrapolation. The TTP methods based on regression analysis, however, reflect such a general tendency of the regression curve that the estimation accuracy of rupture time is low at the lowest and highest stresses in the test stress range. For the purposes of improving the extrapolation accuracy and formulating the master rupture curve, the we authors have developed two estimation procedures employing nonlinear programming : one is an extrapolation prediction method for the creep-rupture curve under constant temperature conditions ; another is an interpolating prediction method for the master creep-rupture curve. According to the examples of extrapolation to the range of 6∼8 times as long as the test duration by the presently developed methods, these prediction methods are also applicable to cases where the deterioration of creep-rupture strength occurs under conditions of high temperature and/or long duration.
Curve fitting
Constant (computer programming)
Cite
Citations (0)
This article investigates five s-parameter extrapolation methods, i.e., Polynomial, Polynomial-Logarithmic, Linear, Static, and Zero-padding. The s-parameters extrapolated using these methods, along with the resulted impedance profiles and eye-diagrams are compared. The study reveals three key observations: First, in contrast to the conventional recommendation that s-parameter extrapolation should be avoided, extrapolation can be doable also useful provided the original s-parameter fulfilling certain conditions. Second, the widely adopted Static method and the Zero-padding method (when extrapolation is used) can exhibit less optimal performances in comparison to other extrapolation methods. Third, which extrapolation method to choose is a case by case decision to make. Practitioners need to carefully check the s-parameters before and after extrapolation in order to ensure the meaningful results can be obtained from the extrapolation.
Zero (linguistics)
Padding
Cite
Citations (7)
The article describes a method for calculation of allowable axle load (technically) bared on the road surface deflection/curvature caused by a known load. Theoretical considerations and sampling in the existing road has given a relationship between the road surface deflection/curvature and the road strength. The road surface deflections are calculated from maximum deflection and curvature observed with Dynafleet equipment, measuring the maximum deflection, Dynafleet Maximum Deflection, and curvature, Surfacing Curvature Index. The results has been drawn up in a simple diagram. /Author/
Road surface
Axle load
Cite
Citations (0)
A new extrapolation procedure which encompasses Aitken's δ2 process and extends to higher orders of convergence is presented. The new extrapolation yields information as to whether an algorithm is converging or diverging as well as a new approximation to the solution point. The new extrapolation technique is compared with existing higher order extrapolation techniques. The value of the new extrapolation is demonstrated analytically and empirically.
Cite
Citations (7)
In this work, we demonstrate using three s-parameter extrapolation methods, i.e., S-matrix-based, SDD21-based, and fitted-SDD21-based, to predict the performance of a high-speed channel. The critical points in applying the s-parameter extrapolation are discussed and the results obtained are compared. The study shows that the s-parameter extrapolation is doable provided certain conditions are fulfilled.
Matrix (chemical analysis)
Cite
Citations (0)