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Online since: July 2014
Authors: Srikanth Nerella, M. Ramalingam, A.K. Jeevanantham
The modeled Recliner was analyzed in LS Dyna to obtain the input data for fatigue calculations.
Seat Structure Damage due to fatigue causes reduction in life of the Recliner in general.
Fatigue Calculations Using Stress data obtained from the solver, the elastic and plastic data is extracted using the hardness of material.
The data is given in tabular form as follows.
Seat Structure Damage due to fatigue causes reduction in life of the Recliner in general.
Fatigue Calculations Using Stress data obtained from the solver, the elastic and plastic data is extracted using the hardness of material.
The data is given in tabular form as follows.
Online since: June 2011
Authors: Yong Xiang Leng, X. Gui, Y. Y. Su, S. Y. Li, H. Sun, J. Mei, N. Huang
The residual thermal stress reduction and adhesive strength increase of a-C:H films can be achieved by depositing the interlayer [1] or gradient layer [2].
Some research data have indicated that the structure and tribological properties of the films are affected by the substrate bias voltage.
Some research data have demonstrated that the reduction of the sp3 bonded content could result in a lower internal stress and hardness [13].
With increasing the bias voltage to -600V or -1000V, the graphitization of a-C:H films structure would be the main reason for the reduction of the hardness and internal stress of a-C:H films.
Some research data have indicated that the structure and tribological properties of the films are affected by the substrate bias voltage.
Some research data have demonstrated that the reduction of the sp3 bonded content could result in a lower internal stress and hardness [13].
With increasing the bias voltage to -600V or -1000V, the graphitization of a-C:H films structure would be the main reason for the reduction of the hardness and internal stress of a-C:H films.
Online since: January 2005
Authors: Manoj Gupta, Maung Aye Thein, Narasimalu Srikanth
Using
the XRD data, the crystalline size of the 10h-MMed samples was calculated using Sherrer equation
[4] (see Table 1).
Comparison of their results shows that the damping capacity increases with the reduction in grain size of the material as we move from a micro-grain size to a nano-grain size sample.
In addition, the results also show that the increase in frequency results in a reduction in the damping capacity of the material.
This can be seen as increased hardness, from 202 HV for micro-grain size Ni sample, to 246 HV for the 10hMMed nano-grain sized Ni sample (see Table 1) which can be explained due to the presence of residual stress [8] as well as due to simultaneous reduction in grain size which can be explained by the Hall-Petch relation [1].
Under a sinusoidal loading, the average strain rate ε& depends on the strain amplitude aε and vibration frequency ωas follows [9]: zp 2 o f G dσ ε η ≈ πσ ∫� (2) 0.000 0.001 0.002 0.003 0.004 0.005300 400 500 600 700 800 900 1000 1100 Frequency (Hz) Damping Loss Factor Ni-10MMed sample Coarse Grain Ni Sample bθ∆ aθ∆ aγ∆ bγ∆ Increasing frequency Resonant point ωr Point b (ωb) Point a (ωa) Imaginary [α(ω)] Real [α(ω)] Fig. 1 (a) Typical receptance frequency response function (FRF) showing the natural frequency and two data points chosen to derive the damping factor and (b) variation of damping loss factor with vibration frequency.
Comparison of their results shows that the damping capacity increases with the reduction in grain size of the material as we move from a micro-grain size to a nano-grain size sample.
In addition, the results also show that the increase in frequency results in a reduction in the damping capacity of the material.
This can be seen as increased hardness, from 202 HV for micro-grain size Ni sample, to 246 HV for the 10hMMed nano-grain sized Ni sample (see Table 1) which can be explained due to the presence of residual stress [8] as well as due to simultaneous reduction in grain size which can be explained by the Hall-Petch relation [1].
Under a sinusoidal loading, the average strain rate ε& depends on the strain amplitude aε and vibration frequency ωas follows [9]: zp 2 o f G dσ ε η ≈ πσ ∫� (2) 0.000 0.001 0.002 0.003 0.004 0.005300 400 500 600 700 800 900 1000 1100 Frequency (Hz) Damping Loss Factor Ni-10MMed sample Coarse Grain Ni Sample bθ∆ aθ∆ aγ∆ bγ∆ Increasing frequency Resonant point ωr Point b (ωb) Point a (ωa) Imaginary [α(ω)] Real [α(ω)] Fig. 1 (a) Typical receptance frequency response function (FRF) showing the natural frequency and two data points chosen to derive the damping factor and (b) variation of damping loss factor with vibration frequency.
Online since: July 2011
Authors: Jerzy Malachowski, Tadeusz Niezgoda
The simulation-based test intended to examine effects of different structures without and with an elastomeric protective panel clearly showed the key role of such panel in reduction of destructive effect of the detonation wave.
Additionally, the data presented in Tab. 4 confirmed the good correlation between computation results and experimental measurements.
Comparison data for cylinder deflection recorded from performed tests.
The thickness reduction of the elastomeric panel.
The performed tests confirmed that due to the plastic deformations in the elastomeric panel the major part of the violating wave was simply consumed by its and, thanks to that, allowed for reduction of the tube wall deflection.
Additionally, the data presented in Tab. 4 confirmed the good correlation between computation results and experimental measurements.
Comparison data for cylinder deflection recorded from performed tests.
The thickness reduction of the elastomeric panel.
The performed tests confirmed that due to the plastic deformations in the elastomeric panel the major part of the violating wave was simply consumed by its and, thanks to that, allowed for reduction of the tube wall deflection.
Online since: June 2020
Authors: Kamila Salasinska, Maciej Celiński, Paweł Kozikowski, Michał K. Leszczyński, Monika Borucka, Agnieszka Gajek
Introduction
Based on the State Fire Service data, it was estimated that only in 2017 there were 125,892 fires in Poland (Central Europe) with the total cost of property damage amounting to USD 313,012,525 [1].
The aim of the study was to identify the crystalline phases present in the histidine diphosphate in comparison to the reference samples of substrates used in the synthetic process as well as literature data.
Cone calorimeter results of unmodified epoxy resin (EP) and resin modified with commercial flame retardant (APP) as well as developed flame-retardant system (EP/S+HF) (standard deviation) Sample designation TTI [s] pHRR [kW/m2] THR [MJ/m2] MARHE [kW/m2] SEA [m2/kg] TSR [m2/ m2] EP 51(17) 1156 (221) 184 (7) 569 (82) 1582 (554) 10353 (3672) EP/APP 52 (5) 227 (5) 94 (10) 148 (10) 508 (9) 2174 (211) EP/S+HF 35 (2) 211 (8) 75 (32) 109 (14) 477 (83) 1463 (537) The use of the developed flame retardant system led to a reduction in time to ignition (TTI) to as little as 35s from the 51s for EP and 52s for EP/APP.
More significantly, the highest reduction in maximum values of heat release rate (pHRR), which is the most important variable used to assess the intensity of fire, was noted for EP/S+HF.
Introduction of 20 wt% of flame retardant system led to a reduction in the time after which the samples ignited but also to a sharp drop in the pHRR, THR, MARHE and TSR values.
The aim of the study was to identify the crystalline phases present in the histidine diphosphate in comparison to the reference samples of substrates used in the synthetic process as well as literature data.
Cone calorimeter results of unmodified epoxy resin (EP) and resin modified with commercial flame retardant (APP) as well as developed flame-retardant system (EP/S+HF) (standard deviation) Sample designation TTI [s] pHRR [kW/m2] THR [MJ/m2] MARHE [kW/m2] SEA [m2/kg] TSR [m2/ m2] EP 51(17) 1156 (221) 184 (7) 569 (82) 1582 (554) 10353 (3672) EP/APP 52 (5) 227 (5) 94 (10) 148 (10) 508 (9) 2174 (211) EP/S+HF 35 (2) 211 (8) 75 (32) 109 (14) 477 (83) 1463 (537) The use of the developed flame retardant system led to a reduction in time to ignition (TTI) to as little as 35s from the 51s for EP and 52s for EP/APP.
More significantly, the highest reduction in maximum values of heat release rate (pHRR), which is the most important variable used to assess the intensity of fire, was noted for EP/S+HF.
Introduction of 20 wt% of flame retardant system led to a reduction in the time after which the samples ignited but also to a sharp drop in the pHRR, THR, MARHE and TSR values.
Online since: March 2007
Authors: Qiang Wang, Zhi Min Zhang, Bao Hong Zhang, B.C. Li
The accuracy of numerical simulation strictly depends on the input data,
which are the physical properties of material.
To simulate the forging of AZ80 magnesium alloy wheel using an implicit FE code MSC/Superform, the data on the flow stress as function of strain, strain rate and temperature established based on the earlier work have to be introduced into the FE package.
Fig.2 shows the schematic diagram of metal flow with different tool radius at the same reduction in height.
When tool radius is 30mm, irrespective of the reduction in height, the folding defect was not noticed compared to the smaller tool radius.
Table 1: Chemical composition of AZ80 billet selected for the study [mass%] The magnesium alloy can was extruded at 400@ with a reduction ratio of 5:1.
To simulate the forging of AZ80 magnesium alloy wheel using an implicit FE code MSC/Superform, the data on the flow stress as function of strain, strain rate and temperature established based on the earlier work have to be introduced into the FE package.
Fig.2 shows the schematic diagram of metal flow with different tool radius at the same reduction in height.
When tool radius is 30mm, irrespective of the reduction in height, the folding defect was not noticed compared to the smaller tool radius.
Table 1: Chemical composition of AZ80 billet selected for the study [mass%] The magnesium alloy can was extruded at 400@ with a reduction ratio of 5:1.
Online since: January 2010
Authors: Jorge M. Antunes, Nataliya A. Sakharova, José Valdemar Fernandes, Marta C. Oliveira
The finite element method is an effective
way for quantifying mechanical properties of multilayered materials and providing detailed data for
better description of their mechanical behaviour under depth-sensing indentation.
Mechanical properties of these materials were selected based on previously reported experimental data [7].
Increasing the number of titanium interlayers in the coating leads to a reduction in the coating's hardness of up to 3.5 % (Fig. 2b).
The reduction of Young's modulus of the coatings with titanium interlayers is 2.5% if one interlayer is present in the coating.
The reduction in Young's modulus is more significant for coatings with titanium interlayers.
Mechanical properties of these materials were selected based on previously reported experimental data [7].
Increasing the number of titanium interlayers in the coating leads to a reduction in the coating's hardness of up to 3.5 % (Fig. 2b).
The reduction of Young's modulus of the coatings with titanium interlayers is 2.5% if one interlayer is present in the coating.
The reduction in Young's modulus is more significant for coatings with titanium interlayers.
Online since: January 2014
Authors: Jun Wei Tao, Jin Bo Guo, Jia Jun Wang, Hong Da Zhang
So that load energy saving and reduction of exhaust can be achieved.
G-language system data acquisition program is shown in Fig. 3.
Torque, Catalyst before the temperature, Flow, Speed, Throttle opening, NGK,Air-fuel ratio Torque Speed Torque(Nm) Speed ,Air-fuel ratio Power(kW) Air flow temperature Air flow Throttle opening(%) Throttle opening ,NGK Air-fuel ratio , Catalyst before temperature Cylinder pressure sensor ,Air-fuel ratio Fig.3 G-language system data acquisition program.
The fuel consumption decreased caused by lean burn mainly due to the decrease of heat transfer losses and pyrolysis losses with the reduction of combustion temperature, oxygen-rich combustion is more fully, Pumped loss is reduced caused by increasing the throttle and so on.
When the air-fuel ratio continue to improve, HC is increasing, which is consistent with the phenomena of reduction of the combustion temperature, the combustion chamber wall quench layer getting thicken and combustion instability, and the increasing of cycle changes.
G-language system data acquisition program is shown in Fig. 3.
Torque, Catalyst before the temperature, Flow, Speed, Throttle opening, NGK,Air-fuel ratio Torque Speed Torque(Nm) Speed ,Air-fuel ratio Power(kW) Air flow temperature Air flow Throttle opening(%) Throttle opening ,NGK Air-fuel ratio , Catalyst before temperature Cylinder pressure sensor ,Air-fuel ratio Fig.3 G-language system data acquisition program.
The fuel consumption decreased caused by lean burn mainly due to the decrease of heat transfer losses and pyrolysis losses with the reduction of combustion temperature, oxygen-rich combustion is more fully, Pumped loss is reduced caused by increasing the throttle and so on.
When the air-fuel ratio continue to improve, HC is increasing, which is consistent with the phenomena of reduction of the combustion temperature, the combustion chamber wall quench layer getting thicken and combustion instability, and the increasing of cycle changes.
Online since: August 2011
Authors: Sombel Diaham, Benoit Schlegel, Rabih Khazaka, Marie Laure Locatelli
The experimental data have been statistically analysed using the Weibull distribution law [6].
An average thickness reduction of 0.5 µm can be estimated each 1000 h of aging for the different thicknesses indicating that this variation is not bulk dependent.
The first degradation at short aging period can be related to the effect of the craters formation on the dielectric breakdown in addition to the thickness reduction.
After 5000 h of aging the two films of 1.5 and 3 µm are short circuited, while a reduction of the breakdown voltage of 87, 75 and 60% is observed for the 4.2, 5.7 and 8 µm respectively.
Data in boxes are refered to extrapolated.
An average thickness reduction of 0.5 µm can be estimated each 1000 h of aging for the different thicknesses indicating that this variation is not bulk dependent.
The first degradation at short aging period can be related to the effect of the craters formation on the dielectric breakdown in addition to the thickness reduction.
After 5000 h of aging the two films of 1.5 and 3 µm are short circuited, while a reduction of the breakdown voltage of 87, 75 and 60% is observed for the 4.2, 5.7 and 8 µm respectively.
Data in boxes are refered to extrapolated.
Online since: January 2013
Authors: Shao Yi Wu, Min Quan Kuang, Bo Tao Song, Xian Fen Hu
From the cluster approach, the spin-orbit coupling coefficients ζ and ζ' and the orbital reduction factors k and k’ containing the ligand orbital and spin-orbit coupling contributions are expressed as follows [10] :
ζ= Nt (ζd0 + λt2ζ p0 /2), ζ' = (Nt Ne)1/2 (ζd0 - λt λeζ p0 /2),
k= Nt (1+ λt2/2), k'= (Nt Ne)1/2 [1-λt (λe + λs A)/2]
By using the free-ion values ζd0 ≈ 356 cm-1 [17] for Fe+ and ζp0 ≈ 220 cm-1[18] for F-, the spin-orbit coupling coefficients ζ, ζ’ and the orbital reduction factors k and k’ are acquired from Eq.(5).
Substituting the above values into Eq (1), the g factors are calculated and compared with the experimental data in Table 2.
The effective impurity-ligand distances R (in Ǻ), group overlap integrals Sγ (and also the integral A), cubic field parameter Dq (in cm-1 ) and covalency factor N, the normalization factors Nγ and the orbital admixture coefficients λγ, the spin-orbit coupling coefficients ζ and ζ´ (in cm-1 )and the orbital reduction factors k and k´ for the cubic Fe+ centers in LiF and NaF.
Discussion Table1 reveals that the theoretical g factors for both Fe+ centers in LiF and NaF show good agreement with the experimental data.
By using the free-ion values ζd0 ≈ 356 cm-1 [17] for Fe+ and ζp0 ≈ 220 cm-1[18] for F-, the spin-orbit coupling coefficients ζ, ζ’ and the orbital reduction factors k and k’ are acquired from Eq.(5).
Substituting the above values into Eq (1), the g factors are calculated and compared with the experimental data in Table 2.
The effective impurity-ligand distances R (in Ǻ), group overlap integrals Sγ (and also the integral A), cubic field parameter Dq (in cm-1 ) and covalency factor N, the normalization factors Nγ and the orbital admixture coefficients λγ, the spin-orbit coupling coefficients ζ and ζ´ (in cm-1 )and the orbital reduction factors k and k´ for the cubic Fe+ centers in LiF and NaF.
Discussion Table1 reveals that the theoretical g factors for both Fe+ centers in LiF and NaF show good agreement with the experimental data.