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Online since: November 2018
Authors: David Moens, Matthias Faes
This paper presents the application of a new method for the identification and quantification
of interval valued spatial uncertainty under scarce data.
To apply these high-dimensional but scarce data, extensions to the novel method are introduced.
Prior to applying the identification and quantification procedure, some operations on the DIC measurement data are necessary.
-0.01 1000 1000 0 800 Y [px] X [px] 500 600 ǫyy [−] 0.01 400 200 0 0.02 Interpolated bi-cubic splines DIC data Fig. 2: Bi-cubic spline interpolation of the measured longitudinal strain field Finally, since the computational cost of obtaining a convex hull scales exponentially with the dimension over which it has to be computed, a reduction of the dimension of the DIC and finite element predicted data is pre-emptive before applying the quantification procedure.
Sensitivity or Bayesian model updating: a comparison of techniques using the DLR AIRMOD test data.
To apply these high-dimensional but scarce data, extensions to the novel method are introduced.
Prior to applying the identification and quantification procedure, some operations on the DIC measurement data are necessary.
-0.01 1000 1000 0 800 Y [px] X [px] 500 600 ǫyy [−] 0.01 400 200 0 0.02 Interpolated bi-cubic splines DIC data Fig. 2: Bi-cubic spline interpolation of the measured longitudinal strain field Finally, since the computational cost of obtaining a convex hull scales exponentially with the dimension over which it has to be computed, a reduction of the dimension of the DIC and finite element predicted data is pre-emptive before applying the quantification procedure.
Sensitivity or Bayesian model updating: a comparison of techniques using the DLR AIRMOD test data.
Online since: June 2013
Authors: Andrea Ghiotti, Michele Novella, Stefania Bruschi
Flow characteristics of new steel grades dedicated to hot stamping
Stefania Bruschi1, a, Andrea Ghiotti1,b and Michele Novella1,c
1DII, University of Padua, via Venezia 1, 35131, Padova, Italy
astefania.bruschi@unipd.it, bandrea.ghiotti@unipd.it, cmichele.novella@studenti.unipd.it
Keywords: sheet metal forming, hot stamping, formability
The reduction of the maximum heating temperature is one of the main goals in the research activities dedicated to hot stamping, to reduce energy consumption and decrease die wear.
Merklein and Lechler determined the influence of temperature and strain rate under process-relevant conditions [4] and the dependency of plastic anisotropy from temperature [5], while many semi-empirical models for the flow stress have been proposed and fitted to the experimental data [6, 7].
Material The first objective of the research consisted in developing new steel grades that could allow a reduction of the process temperatures without affecting significantly their mechanical properties and their formability compared to the commercial Usibor1500P™.
The tensile tests load-displacement curves, provided by the data acquisition system, can be used to assess the point in which plastic instability occurs that corresponds to the point in which the maximum load is recorded.
Merklein and Lechler determined the influence of temperature and strain rate under process-relevant conditions [4] and the dependency of plastic anisotropy from temperature [5], while many semi-empirical models for the flow stress have been proposed and fitted to the experimental data [6, 7].
Material The first objective of the research consisted in developing new steel grades that could allow a reduction of the process temperatures without affecting significantly their mechanical properties and their formability compared to the commercial Usibor1500P™.
The tensile tests load-displacement curves, provided by the data acquisition system, can be used to assess the point in which plastic instability occurs that corresponds to the point in which the maximum load is recorded.
Online since: February 2019
Authors: Vladislav Deev, Evgeny Rakhuba, Evgeny Prusov
The positive effect of thermo-temporal treatment on the structure of materials was confirmed on example of in-situ composites of Al-Mg2Si system, it includes reduction in the average size of endogenous reinforcing phases and changing their morphology to a more compact.
Application of Physical Melt Processing Methods at Production of Aluminum Matrix Composites According to the results of analysis and generalization of the data of works [17-20] in Table 1 the methods of physical effects, tested to date in the production of cast metal matrix composites based on aluminum alloys, are systematized.
Summary The available data indicate that physical methods of melts treatment are an effective means of controlling the structure of alloys to achieve a required quality of cast billets and have significant prospects for industrial use not only in the production of standard alloys but also cast metal matrix composites.
The positive effect of thermo-temporal treatment on the structure of materials was confirmed on example of in-situ composites of Al-Mg2Si system, includes reduction in the average size of endogenous reinforcing phases and changing their morphology to a more compact.
Application of Physical Melt Processing Methods at Production of Aluminum Matrix Composites According to the results of analysis and generalization of the data of works [17-20] in Table 1 the methods of physical effects, tested to date in the production of cast metal matrix composites based on aluminum alloys, are systematized.
Summary The available data indicate that physical methods of melts treatment are an effective means of controlling the structure of alloys to achieve a required quality of cast billets and have significant prospects for industrial use not only in the production of standard alloys but also cast metal matrix composites.
The positive effect of thermo-temporal treatment on the structure of materials was confirmed on example of in-situ composites of Al-Mg2Si system, includes reduction in the average size of endogenous reinforcing phases and changing their morphology to a more compact.
Online since: April 2015
Authors: Alexey V. Pustovalov, Sergey P. Zhuravkov
It was established that with the increase of the electric strength of a gas the wire acquires more energy, enabling the reduction of a particle average size.
In order to make the data processing and the results discussion more convenient, the specific energy injected into the exploding wire and the specific energy evolved at arc discharge phase was presented as dimensionless groups - е/еs and еd/еs, where еs is iron sublimation energy (55.6 J/mm3).
The data received using transmission electron microscope showed that all the obtained particles has a spherical form (Figs. 2a and 2b), and the mean size of particles obtained in Ar is twice as big as that of particles obtained in CO and CO2.
The rate of nanopowder oxidation during heating in air increases with the reduction of particle size of the oxidated powder and preservation of metal iron quantity in it.
In order to make the data processing and the results discussion more convenient, the specific energy injected into the exploding wire and the specific energy evolved at arc discharge phase was presented as dimensionless groups - е/еs and еd/еs, where еs is iron sublimation energy (55.6 J/mm3).
The data received using transmission electron microscope showed that all the obtained particles has a spherical form (Figs. 2a and 2b), and the mean size of particles obtained in Ar is twice as big as that of particles obtained in CO and CO2.
The rate of nanopowder oxidation during heating in air increases with the reduction of particle size of the oxidated powder and preservation of metal iron quantity in it.
Online since: August 2018
Authors: Glenn W. Gale
Now the connection of various products and machines to the internet is generating new and extensive demands for memory (storage of the data), logic (intelligent processing of the data including machine learning), and sensing (e.g., image sensors generating visual data).
With over half the world now connected to the internet [1], connectivity has begun expanding to various devices and machines transferring data and remotely storing it.
Associated massive amounts of generated data require fast local data reduction processing in combination with high volumes of memory storage, while high performance is required for machine learning and applications requiring minimal lag times (latency) such as autonomous driving and assisted surgery.
CAGR: Figure 1: Forecasted compound annual growth rate (CAGR) of semiconductor revenue by product category for 2017 – 2022 (data from reference [5]).
Growth is currently being driven by memory primarily, due to increasing data storage requirements.
With over half the world now connected to the internet [1], connectivity has begun expanding to various devices and machines transferring data and remotely storing it.
Associated massive amounts of generated data require fast local data reduction processing in combination with high volumes of memory storage, while high performance is required for machine learning and applications requiring minimal lag times (latency) such as autonomous driving and assisted surgery.
CAGR: Figure 1: Forecasted compound annual growth rate (CAGR) of semiconductor revenue by product category for 2017 – 2022 (data from reference [5]).
Growth is currently being driven by memory primarily, due to increasing data storage requirements.
Online since: December 2014
Authors: Alexandr Bachurin, Nikolay Kurlaev, Ivan Osipov
The problem of unsteady heat transfer of a part with the quench medium and thermal deformation of aluminum alloy parts is discussed and the results of calculating are compared to the experimental data.
The experimental data confirmed the nature of the deformation obtained by numerical simulation.
The difference between the deformations obtained in the calculations and the experimental data was 23%.
The main problem with this analysis is the convergence of simulation results with experimental data, so for practical applications of the results of such calculations it is necessary to estimate an error by comparing the test calculations either with tasks having known solutions or with experimental data.
He, FEM simulation of quenching process in A357 aluminum alloy cylindrical bars and reduction of quench residual stress through cold stretching process, Comput.
The experimental data confirmed the nature of the deformation obtained by numerical simulation.
The difference between the deformations obtained in the calculations and the experimental data was 23%.
The main problem with this analysis is the convergence of simulation results with experimental data, so for practical applications of the results of such calculations it is necessary to estimate an error by comparing the test calculations either with tasks having known solutions or with experimental data.
He, FEM simulation of quenching process in A357 aluminum alloy cylindrical bars and reduction of quench residual stress through cold stretching process, Comput.
Online since: November 2011
Authors: M.Z.M. Saman, A.R. Hemdi, Norhayati Zakuan
Survey methodology was employed to collect data.
While useful, the design related data tends to be limited and no or very little detailed data is included.
A survey is considered the most economical among methods available for data collection due to its ability in performing efficient data collection [11], which had been used by the authors.
Mail survey was conducted to collect data in this study.
The model is tested for the data from Malaysia automotive respondents (n=104).
While useful, the design related data tends to be limited and no or very little detailed data is included.
A survey is considered the most economical among methods available for data collection due to its ability in performing efficient data collection [11], which had been used by the authors.
Mail survey was conducted to collect data in this study.
The model is tested for the data from Malaysia automotive respondents (n=104).
Online since: June 2009
Authors: C.A. Featherston, Karen M. Holford, Bea Greaves
The Engineering Sciences Data Unit (ESDU) aerodynamics document on
structural design against fatigue [13] relates vibration sources and induced structural excitation to
fatigue avoidance, and states "The primary sources of structural excitation are due to acoustic and
aerodynamic generation although structurally transmitted vibration may have an additional
influence."
LabVIEW software was used for data acquisition, to record the signals produced by the energy harvesters, and export the logged information into Microsoft Excel spreadsheets for analysis.
The resulting spreadsheets contained the values of voltage or current recorded at a rate of 500s -1 and the RMS value for every second of data recorded.
The calculations were made using the method from the ESDU aerodynamics data item "Estimation of the surface pressure fluctuations in the turbulent boundary layer of a flight vehicle" [17] and atmospheric data from the ESDU document giving atmospheric data [18].
Atmospheric data for performance calculations. http://www.esdu.com
LabVIEW software was used for data acquisition, to record the signals produced by the energy harvesters, and export the logged information into Microsoft Excel spreadsheets for analysis.
The resulting spreadsheets contained the values of voltage or current recorded at a rate of 500s -1 and the RMS value for every second of data recorded.
The calculations were made using the method from the ESDU aerodynamics data item "Estimation of the surface pressure fluctuations in the turbulent boundary layer of a flight vehicle" [17] and atmospheric data from the ESDU document giving atmospheric data [18].
Atmospheric data for performance calculations. http://www.esdu.com
Online since: May 2015
Authors: Zhi Jian Wu, Xiu Shen Ye, Tan Guo, Hui Fang Zhang, Hai Ning Liu, Can Gao
A stable Ag NPs suspension was synthesized via the reduction of silver nitrate using sodium citrate.
Therefore, great efforts have been contributed to studying methods for the preparation of Ag NPs, including chemical reduction [4], thermal decomposition [5], and laser ablation [6].
Chemical reduction is the most frequently approach to synthesis Ag NPs using sodium borohydride or citrate as reducing and protecting agents, because it is relatively simple and efficient.
Further treatment with APTES and AEAPTES results in sharp increase in the data 52.2±0.5 °and 42.37±1.0 °, respectively, indicating that the wettability of the surfaces have changed.
Therefore, great efforts have been contributed to studying methods for the preparation of Ag NPs, including chemical reduction [4], thermal decomposition [5], and laser ablation [6].
Chemical reduction is the most frequently approach to synthesis Ag NPs using sodium borohydride or citrate as reducing and protecting agents, because it is relatively simple and efficient.
Further treatment with APTES and AEAPTES results in sharp increase in the data 52.2±0.5 °and 42.37±1.0 °, respectively, indicating that the wettability of the surfaces have changed.
Online since: January 2005
Authors: C.S. Kim, S.I. Kwun, S.J. Hong, Jai Won Byeon
Ultrasonic attenuation coefficient was found to have a linear correlation with the
hardness, and suggested accordingly as a potential nondestructive evaluation parameter for
assessing the mechanical strength reduction of the isothermally degraded 2.25Cr-1Mo steel.
However, this steel is known to be subject to thermal degradation after long exposure to high temperatures, which causes strength reduction due to coarsening of carbides, precipitation of stable ones and/or softening of matrix [1,2].
The ultrasonic measurement system used in this experiment consisted of a pulser/receiver (Panametric 5601A/TT) for pulsating high frequency wave, a digital storage oscilloscope (Lecroy 9310) for analog/digital convert, three piezoelectric longitudinal broad band probe (Panametrics) with each center frequency of 5, 10 and 35 MHz, a immersion tank with a unit of parallelismadjustment and a personal computer with a commercial software for data acquisition and signal processing. 100-times averaged pulse echo signal received in time domain was fast Fourier transformed to obtain a frequency spectrum, from which attenuation coefficients at various frequency components were determined.
The reduction in hardness with increasing thermal degradation time is roughly attributed to the coarsening of carbides, although other microstructural factor such as depletion of solution hardening elements also plays some role [8].
However, this steel is known to be subject to thermal degradation after long exposure to high temperatures, which causes strength reduction due to coarsening of carbides, precipitation of stable ones and/or softening of matrix [1,2].
The ultrasonic measurement system used in this experiment consisted of a pulser/receiver (Panametric 5601A/TT) for pulsating high frequency wave, a digital storage oscilloscope (Lecroy 9310) for analog/digital convert, three piezoelectric longitudinal broad band probe (Panametrics) with each center frequency of 5, 10 and 35 MHz, a immersion tank with a unit of parallelismadjustment and a personal computer with a commercial software for data acquisition and signal processing. 100-times averaged pulse echo signal received in time domain was fast Fourier transformed to obtain a frequency spectrum, from which attenuation coefficients at various frequency components were determined.
The reduction in hardness with increasing thermal degradation time is roughly attributed to the coarsening of carbides, although other microstructural factor such as depletion of solution hardening elements also plays some role [8].