scholarly journals Dynamic Line Scan Thermography Optimisation Using Response Surfaces Implemented on PVC Flat Bottom Hole Plates

2021 ◽  
Vol 11 (4) ◽  
pp. 1538 ◽  
Author(s):  
Simon Verspeek ◽  
Jona Gladines ◽  
Bart Ribbens ◽  
Xavier Maldague ◽  
Gunther Steenackers
Keyword(s):  
Material Properties ◽  
Optimal Parameter ◽  
Response Surfaces ◽  
Flat Bottom ◽  
Line Scan ◽  
Size And Shape ◽  
Set Up ◽  
Detail Loss ◽  
Optimal Set ◽  
Line Scan Thermography

Nowadays, performing dynamic line scan thermography (DLST) is very challenging, and therefore an expert is needed in order to predict the optimal set-up parameters. The parameters are mostly dependent on the material properties of the object to be inspected, but there are also correlations between the parameters themselves. The interrelationship is not always evident even for someone skilled in the art. Therefore, optimisation using response surface can give more insights in the interconnections between parameters, but also between the material properties and the variables. Performing inspections using an optimised parameter set will result in high contrast thermograms showing the size and shape of the defect accurately. Using response surfaces to predict the optimal parameter set enables to perform fast measurements without the need of extensive testing to find adequate measurement parameters. Differing from the optimal parameters will result in contrast loss or detail loss of the size and shape of the detected defect.

scholarly journals Extreme Waves in Crossing Sea States

2018 ◽  
Vol 01 (01) ◽  
pp. 1850001 ◽  
Author(s):  
Joseph Brennan ◽  
John M. Dudley ◽  
Frédéric Dias
Keyword(s):  
Rogue Waves ◽  
Order Effects ◽  
Third Order ◽  
Flat Bottom ◽  
Spectral Content ◽  
Wave Event ◽  
The Mean ◽  
Wind Sea ◽  
Set Up ◽  
Wavenumber Region

The evolution of crossing sea states and the emergence of rogue waves in such systems are studied via numerical simulations performed using a higher order spectral (HOS) method to solve the free surface Euler equations with a flat bottom. Two classes of crossing sea states are analyzed: one using directional spectra from the Draupner wave crossing at different angles, another considering a Draupner-like spectra crossed with a narrowband JONSWAP state to model spectral growth between wind sea and swell. These two classes of crossing sea states are constructed using the spectral output of a WAVEWATCH III hindcast on the Draupner rogue wave event. We measure ensemble statistical moments as functions of time, finding that although the crossing angle influences the statistical evolution to some degree, there are no significant third-order effects present. Additionally, we pay particular attention to the mean sea level measured beneath extreme crest heights, the elevation of which (set up or set down) is shown to be related to the spectral content in the low wavenumber region of the corresponding spectrum.

Impacts of Temperature on Mechanical Properties of FGMs

2014 ◽  
Vol 633-634 ◽  
pp. 391-395
Author(s):  
Wen Guang Liu ◽  
Cheng Yan
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Hypersonic Vehicle ◽  
Harsh Environment ◽  
Power Law Distribution ◽  
Temperature Dependent ◽  
Gradient Materials ◽  
Functionally Gradient ◽  
Property Model ◽  
Set Up

According to the Hypersonic Vehicle harsh environment, impacts of temperature on the mechanical properties for functionally gradient materials are studied. A power-law distribution of material is applied between the two pure materials; a material property model of FGMs is built. Several temperature conditions are set up and the results are obtained in the end through numerical analysis. It can be shown that the material properties of FGMs plate are temperature-dependent and vary along the thickness in terms of volume fractions of constituents.

Analysis of a Struck Ship With Damage Opening: Influence From Model and Material Properties Uncertainties

2010 ◽  
Author(s):  
Per Hogstro¨m ◽  
Jonas W. Ringsberg ◽  
Erland Johnson
Keyword(s):  
Material Properties ◽  
Shear Failure ◽  
Forming Limit ◽  
Model Description ◽  
Current Investigation ◽  
Sea State ◽  
Size And Shape ◽  
Constitutive Material Model ◽  
Damage Stability ◽  
Selection Of

The conditions for damage stability and survivability of a ship struck in a collision in arbitrary sea-state are, from a structural point of view, determined by the size and shape of the damage opening in its side shell. In the current investigation, explicit finite element analyses (FEA) are presented of a ship-to-ship collision scenario in which the damage opening of a struck ship is calculated for a selection of damage degradation models and realistic material properties, here referred to as model and material properties uncertainties. The model uncertainty is considered as a possible (user-related) insecurity in the selection of the most appropriate damage criterion for the analysis; the shear failure and the forming limit diagram (FLD) criteria were compared in the current investigation. The uncertainty in material properties is accounted for in the constitutive material model description and the material parameters used in the two criteria. The size and shape of the damage openings predicted by the FEA are used in damage stability analyses in which the struck ship is subjected to wave motions in an arbitrary sea-state and flooding into the damage opening. The survivability of the struck ship is estimated for all of the damage opening cases. One of the main conclusions is that the high degree of accuracy that a researcher on structure analysis strives for has to be considered together with the natural variation of the sea-state that defines the characteristics in the following damage stability analysis. Consequently, by adoption of a holistic approach, in which structural integrity and damage stability research are combined using a systematic parameter (sensitivity) and collision-scenario-based analysis, simplified models and criteria can be developed more efficiently and with higher precision. It will also be clearer which variables are the most important to focus on when analyzing the survivability or risk for capsizing.

scholarly journals Expectations affect the perception of material properties

2019 ◽  
Author(s):  
Lorilei M. Alley ◽  
Alexandra C. Schmid ◽  
Katja Doerschner
Keyword(s):  
Optical Properties ◽  
Visual Perception ◽  
Material Properties ◽  
Time Data ◽  
Material Appearance ◽  
Typical Material ◽  
Material Behaviors ◽  
Set Up ◽  
High Level ◽  
Cue Conflict

ABSTRACTMany objects that we encounter have ‘typical’ material qualities: spoons are hard, pillows are soft, and jell-O dessert is wobbly. Over a lifetime of experiences, strong associations between an object and its typical material properties may be formed, and these associations not only include how glossy, rough or pink an object is, but also how it behaves under force: we expect knocked over vases to shatter, popped bike tires to deflate, and gooey grilled cheese to hang between two slices of bread when pulled apart. Here we ask how such rich visual priors affect the visual perception of material qualities and present a particularly striking example of expectation violation. In a cue conflict design, we pair computer-rendered familiar objects with surprising material behaviors (a linen curtain shattering, a porcelain teacup wrinkling, etc.) and find that material qualities are not solely estimated from the object’s kinematics (i.e. its physical (atypical) motion while shattering, wrinkling, wobbling etc.); rather, material appearance is sometimes “pulled” towards the “native” motion, shape, and optical properties that are associated with this object. Our results, in addition to patterns we find in response time data, suggest that visual priors about materials can set up high-level expectations about complex future states of an object and show how these priors modulate material appearance.

SLIDING WEAR PERFORMANCE OF NANO CUO PARTICLES - SHORT SISAL FIBERS - POLYAMIDE 66 HYBRID COMPOSITES

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Rajasekhar P ◽  
Ganesan G ◽  
Senthilkumar M
Keyword(s):  
Hybrid Composites ◽  
Optimal Parameter ◽  
Glass Fibers ◽  
Industrial Applications ◽  
Response Surfaces ◽  
Parameter Analysis ◽  
Polyamide 66 ◽  
Load Carrying ◽  
Sisal Fibers ◽  
Short Carbon

Polymers and their composites are being increasingly employed in view of their good strengths and corrosion resistance. The features that make the polymer composites in industrial applications are the opportunities to tailor their properties with special fillers. For instance, short carbon and glass fibers have been successfully employed to improve the strength and therefore the load carrying capacity of polyamide composites can also be improved Optimization of parameters is an important in the tribological process. Response surface methodology (RSM) based optimal parameter analysis was performed to investigate the change of responses like wear rate (WR) and coefficient of friction (COF) with the change of input parameters to determine optimum setting of process parameters such as normal force, sliding velocity and reinforcement for achieving minimum WR and COF. The regression model generates the response surfaces. The present study is to optimize the parameter setting for combined responses.

Parameters Optimization of Turning Free Cutting Steel Based on the Coupling Method of Response Surfaces

2011 ◽  
Vol 188 ◽  
pp. 301-306 ◽  
Author(s):  
Zhi Qiang Liu ◽  
Xiao Jiang Cai ◽  
Shu Han ◽  
Ming Chen ◽  
Qing Long An
Keyword(s):  
Cutting Parameters ◽  
Response Surfaces ◽  
Parameters Optimization ◽  
Coupling Method ◽  
Optimal Selection ◽  
Turning Process ◽  
Processing Efficiency ◽  
Cutting Steel ◽  
Set Up ◽  
Made In

Turning parameters are subject to processing efficiency, cutting force and surface quality, etc. A method, called the coupling method of response surfaces, is presented in this paper to select cutting parameters subjected to several constraints. An experiment of turning free cutting steel is made in order to set up the model. The results from the optimal selection provide a basis prototype for the cutting parameters. It can meet the needs of the turning process in industrial production.

An inverse approach to the characterisation of material parameters of piezoelectric discs with triple-ring-electrodes

2019 ◽  
Vol 86 (2) ◽  
pp. 59-65
Author(s):  
Nadine Feldmann ◽  
Benjamin Jurgelucks ◽  
Leander Claes ◽  
Veronika Schulze ◽  
Bernd Henning ◽  
...  
Keyword(s):  
Material Properties ◽  
Measurement Procedure ◽  
Material Parameters ◽  
Inverse Approach ◽  
Precise Knowledge ◽  
Simulation Based Design ◽  
Simulation Based ◽  
Set Up ◽  
Optimisation Procedure ◽  
Single Set

AbstractFor its usage in simulation-based design processes a precise knowledge of the employed material properties is inevitable. In the case of piezoelectric ceramics, the provided material parameters often suffer from large uncertainties and even inconsistencies since the standardised measurement procedure needs several specimens to determine a single set of material parameters. In contrast, the presented measurement set-up allows to calculate material parameters using one unique disc-shaped specimen with an optimised electrode topology. Using an inverse problem approach, fitting material parameters can be found using an optimisation procedure.

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