Temperature Spectrums of an Automotive Environment for Fatigue Reliability Analysis

1994 ◽  
Vol 37 (6) ◽  
pp. 19-25
Author(s):  
Jimmy Hu ◽  
Ken Salisbury
Keyword(s):  
Heat Dissipation ◽  
Sun Exposure ◽  
Maximum Temperature ◽  
Fatigue Reliability ◽  
Temperature Spectrum ◽  
Electronic Products ◽  
Automotive Components ◽  
Thermal Fatigue Life ◽  
Temperature Ranges ◽  
Nominal Temperature

The temperature spectrum of an automotive environment is a necessary input to predict thermal fatigue life, to estimate product reliability, and to specify accelerated thermal cycle testing for automotive components. This paper investigates the temperature profiles of electronic products located in the engine compartment (EC), the engine-mounted (EM) area, and the passenger/luggage (P/L) compartment, and develops the nominal temperature spectrums for these vehicle locations. The daily climatic temperatures of various geographical areas in the U.S. are analyzed. The effects of sun exposure and operational heat dissipation on the maximum temperature in three vehicle compartments are investigated. Due to the proportionality of mechanical stress/strain ranges and temperature ranges, the temperature spectrums are constructed by using the rainflow method for fatigue cycle counting.

scholarly journals Quantifying sea surface temperature ranges of the Arabian Sea for the past 20 000 years

2011 ◽  
Vol 7 (4) ◽  
pp. 1337-1349 ◽  
Author(s):  
G. M. Ganssen ◽  
F. J. C. Peeters ◽  
B. Metcalfe ◽  
P. Anand ◽  
S. J. A. Jung ◽  
...  
Keyword(s):  
Arabian Sea ◽  
Isotope Composition ◽  
Planktonic Foraminifera ◽  
Sediment Cores ◽  
Maximum Temperature ◽  
Physical Parameters ◽  
Seasonal Temperature ◽  
Mean Values ◽  
The Past ◽  
Temperature Ranges

Abstract. The oxygen isotopic composition of planktonic foraminifera tests is one of the widest used geochemical tools to reconstruct past changes of physical parameters of the upper ocean. It is common practice to analyze multiple individuals from a mono-specific population and assume that the outcome reflects a mean value of the environmental conditions during calcification of the analyzed individuals. Here we present the oxygen isotope composition of individual specimens of the surface-dwelling species Globigerinoides ruber and Globigerina bulloides from sediment cores in the Western Arabian Sea off Somalia, inferred as indicators of past seasonal ranges in temperature. Combining the δ18O measurements of individual specimens to obtain temperature ranges with Mg/Ca based mean calcification temperatures allows us to reconstruct temperature extrema. Our results indicate that over the past 20 kyr the seasonal temperature range has fluctuated from its present value of 16 °C to mean values of 13 °C and 11 °C for the Holocene and LGM, respectively. The data for the LGM suggest that the maximum temperature was lower, whilst minimum temperature remained approximately constant. The rather minor variability in lowest summer temperatures during the LGM suggests roughly constant summer monsoon intensity, while upwelling-induced productivity was lowered.

scholarly journals On the Ratchet Analysis of a Cracked Welded Pipe

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Tianbai Li ◽  
Haofeng Chen ◽  
Weihang Chen ◽  
James Ure
Keyword(s):  
Yield Stress ◽  
Maximum Temperature ◽  
Limit Loads ◽  
Axial Tension ◽  
Circumferential Crack ◽  
Temperature Load ◽  
Cyclic Temperature ◽  
Temperature Ranges ◽  
Welded Pipe ◽  
Linear Matching Method

This paper presents the ratchet limit analysis of a pipe with an axisymmetric circumferential crack in a mismatched weld by using the extended linear matching method (LMM). Two loading conditions are considered: (i) a cyclic temperature load and a constant internal pressure and (ii) a cyclic temperature load and a constant axial tension. Individual effects of (i) the geometry of the Weld Metal (WM), (ii) the size of the crack, (iii) the location of the crack, and (iv) the yield stress of WM on the ratchet limits, maximum temperature ranges to avoid ratchetting, and limit loads are investigated. Influence functions of the yield stress of WM on the maximum temperature ranges and limit loads are generated. The results confirm the applicability of the extended LMM to the cracked welded pipe.

Ratchet Limits for a Crack in a Welded Pipe Subjected to a Cyclic Temperature Load and a Constant Mechanical Load

2011 ◽  
Author(s):  
Tianbai Li ◽  
Haofeng Chen ◽  
Weihang Chen ◽  
James Ure
Keyword(s):  
Yield Stress ◽  
Mechanical Load ◽  
Maximum Temperature ◽  
Limit Loads ◽  
Axial Tension ◽  
Temperature Load ◽  
Cyclic Temperature ◽  
Temperature Ranges ◽  
Welded Pipe ◽  
Symmetric Crack

This paper presents the ratchet limit analysis of a pipe with a symmetric crack in a mismatched weld by using the extended Linear Matching Method (LMM). Two loading conditions are considered: i) a cyclic temperature load and a constant internal pressure; and ii) a cyclic temperature load and a constant axial tension. Individual effects of i) the geometry of the Weld Metal (WM), ii) the size of the crack, iii) the location of the crack and iv) the yield stress of WM on the ratchet limits, maximum temperature ranges to avoid ratchetting and limit loads are investigated. Influence functions of the yield stress of WM on the maximum temperature ranges and limit loads are generated. The results confirm the applicability of the extended LMM to the cracked welded pipe.

Computational analysis of temperature distribution in microwave-heated potatoes

2020 ◽  
Vol 26 (6) ◽  
pp. 465-474
Author(s):  
Deepak Singh ◽  
Dhananjay Singh ◽  
Sattar Husain
Keyword(s):  
Mathematical Model ◽  
Temperature Distribution ◽  
Computational Analysis ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Maximum Temperature ◽  
Bacterial Inactivation ◽  
Food Material ◽  
Drying Time ◽  
Temperature Ranges

This research article reports the computational analysis of temperature distribution in microwave-heated convenience food such as potato. The detailed study of temperature (because temperature is a function of bacterial inactivation) and microwave powers along with drying time for the preservation of food material has been presented. Therefore, a mathematical model for potato sample is developed to predict the behavior of temperature distribution at each possible point and different shapes (slab, cylindrical, and spherical) of food material. The developed mathematical model is programmed by MATLAB software. Another parameter, microwave power is also a function of temperature. The ranging values of various microwave powers (125 W, 375 W, 625 W, 875 W, and 1250 W) along with different values of drying time (0 to 10 minutes) have been used for computation. The obtained results show the uniformity of temperature distribution throughout the whole product in the form of a three-dimensional structure. The model provides the minimum and maximum temperature ranges in specimens without performing an experiment which depicts the condition of bacterial inactivation.

Study on the Influence of Temperature and Stress Field to PCB’s Modal

2012 ◽  
Vol 271-272 ◽  
pp. 1441-1445
Author(s):  
Qin Luo ◽  
Su Juan Zhang ◽  
Xiao Zhang
Keyword(s):  
Temperature Field ◽  
Stress Field ◽  
Modal Analysis ◽  
Heat Flux Density ◽  
Heat Dissipation ◽  
Transient Temperature ◽  
Electronic Products ◽  
Transient Stress ◽  
Transient Temperature Field ◽  
Pcb Design

With the increasing integration of electronic products, the heat flux density is increasing. Research on the heat dissipation of the PCB attracts more attention. Temperature field of the electronic products always changes a lot, usually leading to a transient stress field in the PCB. Due to the transient temperature field and transient stress field, the PCB’s modal changed. In this paper, the temperature field and the stress field are obtained to explain the reason of the change. The influence on PCB’s modal caused by the temperature field and the stress field are analyzed, on the basis of PCB’s thermal modal analysis, which provide a reference for the PCB design and modal analysis in the future.

scholarly journals Simulation of heat dissipation model of lithium-ion battery pack

2021 ◽  
Vol 300 ◽  
pp. 01014
Author(s):  
Maode Li ◽  
Chuan He ◽  
Jinkui Zheng
Keyword(s):  
Phase Change ◽  
Temperature Rise ◽  
Heat Dissipation ◽  
Lithium Ion ◽  
Maximum Temperature ◽  
Air Cooling ◽  
Power Battery ◽  
Staggered Arrangement ◽  
Dissipation Model ◽  
Cooling Methods

Lithium-ion power battery has become an important part of power battery. According to the performance and characteristics of lithiumion power battery, the influence of current common charge and discharge and different cooling methods on battery performance was analysed in this paper. According to the software simulation, in the 5C charge-discharge cycle, the maximum temperature of the cells with regular arrangement is 57.97°C, the maximum temperature of the cells with staggered arrangement is 55.83°C, and the maximum temperature of phase change cooling is 47.42°C. The most important thing is that the temperature difference between the cells with phase change cooling is only 5.5°C. Some simulation results of air cooling and phase change show that phase change cooling can control the heat dissipation and temperature rise of power battery well. The research in this paper can provide better theoretical guidance for the temperature rise, heat transfer and thermal management of automotive power battery.

scholarly journals Environmental correlates and functional consequences of bill divergence in island song sparrows

2021 ◽  
Author(s):  
Maybellene P Gamboa ◽  
Cameron K Ghalambor ◽  
T Scott Sillett ◽  
W Chris Funk ◽  
Ross A Furbush ◽  
...  
Keyword(s):  
Surface Area ◽  
Heat Dissipation ◽  
Song Sparrow ◽  
Maximum Temperature ◽  
Foraging Efficiency ◽  
Channel Islands ◽  
Environmental Selection ◽  
Song Sparrows ◽  
Functional Consequences ◽  
Bill Morphology

Inferring the environmental selection pressures responsible for phenotypic variation is a challenge in adaptation studies as traits often have multiple functions and are shaped by complex selection regimes. We provide experimental evidence that morphology of the multifunctional avian bill is related to climate, not foraging efficiency, in song sparrows (Melospiza melodia) on the California Channel Islands. Our research builds on a study in song sparrow museum specimens that demonstrated a positive correlation between bill surface area and maximum temperature, suggesting a greater demand for dry heat dissipation in hotter, xeric environments. We sampled contemporary sparrow populations across three climatically distinct islands to test the alternate hypotheses that song sparrow bill morphology is either a product of vegetative differences with functional consequences for foraging efficiency or related to maximum temperature and, consequently, important for thermoregulation. Measurements of >500 live individuals indicated a significant, positive relationship between maximum temperature and bill surface area when correcting for body size. In contrast, maximum bite force, seed extraction time, and vegetation on breeding territories (a proxy for food resources) were not significantly associated with bill dimensions. While we cannot exclude the influence of foraging ability and diet on bill morphology, our results are consistent with the hypothesis that variation in song sparrows' need for thermoregulatory capacity across the northern Channel Islands selects for divergence in bill surface area.

scholarly journals Analisa Model Evaporasi dan Evapotranspirasi Menggunakan Pemodelan Matematika pada Visual Basic di Kabupaten Maros

2021 ◽  
Vol 5 (3) ◽  
pp. 179-196
Author(s):  
Ahmad Fausan ◽  
Budi Indra Setiawan ◽  
Chusnul Arif ◽  
Satyanto Krido Saptomo
Keyword(s):  
Sun Exposure ◽  
Visual Basic ◽  
Basic Program ◽  
Coefficient Of Determination ◽  
Maximum Temperature ◽  
Suitability Analysis ◽  
Climate Data ◽  
South Sulawesi ◽  
A Value ◽  
Evaporation Models

The approach to calculating evaporation and evapotranspiration, both potential and actual, varies widely. The models used to estimate the amount of evapotranspiration, particularly at the Maros Climatology Station, Maros Regency, South Sulawesi. Evaporation models use the Penman, Priestley, Bruin, and Valiantzas models while evapotranspiration models use the Penman, Hargreaves, Jensen-Haise, Penman-Monteith, Radiation, Turc, and Makkink models, where all of these methods use climate data, such as are the minimum temperature (Tn), maximum temperature (Tx), air temperature (Ta), average humidity (RH), rainfall (R), duration of sun exposure (SS), and maximum wind speed (U) in calculations using Visual basic program in Microsoft Excel in the form of code. Thus, it is necessary to conduct an analysis of the suitability of the model to the results of the observations in order to find out which model is suitable according to the results of the largest coefficient of determination (R2). Based on the results of the model suitability analysis, a selected model was obtained, namely the Valiantzas model with a value of 0.980 in the evaporation calculation and the Jensen-Haise model, namely 0.889.

scholarly journals Assessment of indoor thermal environment of Aceh house based on WBGT index

2021 ◽  
Vol 881 (1) ◽  
pp. 012023
Author(s):  
Muslimsyah ◽  
A Munir ◽  
Y Away ◽  
Abdullah ◽  
K Huda ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Ventilation System ◽  
Vernacular Architecture ◽  
Maximum Temperature ◽  
Cooling Process ◽  
Temperature Index ◽  
Indoor Thermal Environment ◽  
Temperature Ranges

Abstract Thermal comfort is one of the standard assessments of building thermal environment. Air movement is an important parameter for in a naturally ventilated to achieve thermal comfort by accelerating the evaporative cooling process on the human body. Aceh House has a standard of thermal comfort with a vernacular architecture with a natural ventilation system. This vernacular architectural building has a fairly high harmonization of the environment because it has undergone a process of adaptation. In this study, observations were made at the Original House (OH), the Adaptive Reuse House (ARH), and the Aceh Modified House (AMH). By using the method of assessing changes in environmental comfort, using Wet Bulb Temperature Index (WBGT) method, the minimum and maximum temperature ranges are 25°C and 30°C. In the WBGT thermal rating, AMH has the higher thermal and is followed by ARH and OH respectively. Thus, OH has lower thermal compared to other Aceh houses.

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