Prediction of Temperature Distributions in Axisymmetric Compression and Torsion

1975 ◽  
Vol 97 (2) ◽  
pp. 113-120 ◽  
Author(s):  
G. D. Lahoti ◽  
T. Altan
Keyword(s):  
Metal Flow ◽  
Experimental Studies ◽  
Numerical Approach ◽  
The Other ◽  
Temperature Fields ◽  
Upper Bound Method ◽  
Temperature Distributions ◽  
Nonsteady State ◽  
Deformation Processes ◽  
Ram Speed

Two numerical methods, one for axisymmetric compression and the other for axisymmetric torsion, have been developed to predict nonsteady-state temperature fields in these deformation processes. In compression, the upper-bound method has been used to determine the velocity field prior to temperature calculations. In both compression and torsion, the predicted temperatures agree well with experimental data obtained by other workers. The compression analysis has been also used for investigating (1) the effect of friction upon temperatures and (2) the effect of ram speed upon metal flow and temperatures. The results of these investigations indicate that the numerical approach predicts, within approximations, the trends observed in experimental studies.

Milling Curves Influence in Ring Rolling Processes

2014 ◽  
Vol 622-623 ◽  
pp. 956-963 ◽  
Author(s):  
Luca Giorleo ◽  
Elisabetta Ceretti ◽  
Claudio Giardini
Keyword(s):  
Numerical Approach ◽  
The Other ◽  
Ring Rolling ◽  
Roll Speed ◽  
Forming Process ◽  
Industrial Case Study ◽  
Industrial Environment ◽  
Ring Shape ◽  
Deformation Processes

Ring Rolling is a complex hot forming process used for the production of shaped rings, seamless and axis symmetrical workpieces. The main advantage of workpieces produced by ring rolling, compared to other technological processes, is given by the size and orientation of grains, especially on the worked surface which give to the final product excellent mechanical properties. In this process different rolls (Idle, Axial, Guide and Driver) are involved in generating the desired ring shape. Since each roll is characterized by a speed law that can be set independently by the speed law imposed to the other rolls, an optimization is more critical compared with other deformation processes. Usually, in industrial environment, a milling curve is introduced in order to correlate the Idle and Axial roll displacement, however it must be underlined that different milling curves lead to different loads and energy for ring realization. In this work an industrial case study was modeled by a numerical approach: different milling curves characterized by different Idle and Axial roll speed laws (linearly decreasing, constant, linearly increasing) were designed and simulated. The results were compared in order to identify the best milling curve that guarantees a good quality ring (higher diameter, lower fishtail) with lower loads and energy required for manufacturing.

Effects of Attachment Styles on the Experience of Equity in Heterosexual Couples Relationships

2003 ◽  
Vol 50 (4) ◽  
pp. 298-310 ◽  
Author(s):  
Ina Grau ◽  
Jörg Doll
Keyword(s):  
Attachment Theory ◽  
Attachment Style ◽  
Intimate Relationships ◽  
Attachment Styles ◽  
Experimental Studies ◽  
The Other ◽  
Heterosexual Couples ◽  
Secure Attachment ◽  
Dependent Variables ◽  
Equity Ratio

Abstract. Employing one correlational and two experimental studies, this paper examines the influence of attachment styles (secure, anxious, avoidant) on a person’s experience of equity in intimate relationships. While one experimental study employed a priming technique to stimulate the different attachment styles, the other involved vignettes describing fictitious characters with typical attachment styles. As the specific hypotheses about the single equity components have been developed on the basis of the attachment theory, the equity ratio itself and the four equity components (own outcome, own input, partner’s outcome, partner’s input) are analyzed as dependent variables. While partners with a secure attachment style tend to describe their relationship as equitable (i.e., they give and take extensively), partners who feel anxious about their relationship generally see themselves as being in an inequitable, disadvantaged position (i.e., they receive little from their partner). The hypothesis that avoidant partners would feel advantaged as they were less committed was only supported by the correlational study. Against expectations, the results of both experiments indicate that avoidant partners generally see themselves (or see avoidant vignettes) as being treated equitably, but that there is less emotional exchange than is the case with secure partners. Avoidant partners give and take less than secure ones.

Computational and experimental studies of the strength of full-scale samples of pipes with defects "metal loss" and "dent with groove"

2020 ◽  
Vol 10 (3) ◽  
pp. 226-233
Author(s):  
Dmitry A. Neganov ◽  
◽  
Victor M. Varshitsky ◽  
Andrey A. Belkin ◽  
◽  
...  
Keyword(s):  
Internal Pressure ◽  
Experimental Studies ◽  
Full Scale ◽  
The Other ◽  
Metal Loss ◽  
Calculation Methods ◽  
Reliable Operation ◽  
Sufficient Stability ◽  
Comparative Results ◽  
The Moment

The article contains the comparative results of the experimental and calculated research of the strength of a pipeline with such defects as “metal loss” and “dent with groove”. Two coils with diameter of 820 mm and the thickness of 9 mm of 19G steel were used for full-scale pipe sample production. One of the coils was intentionally damaged by machining, which resulted in “metal loss” defect, the other one was dented (by press machine) and got groove mark (by chisel). The testing of pipe samples was performed by applying static internal pressure to the moment of collapse. The calculation of deterioration pressure was carried out with the use of national and foreign methodical approaches. The calculated values of collapsing pressure for the pipe with loss of metal mainly coincided with the calculation experiment results based on Russian method and ASME B31G. In case of pipe with dent and groove the calculated value of collapsing pressure demonstrated greater coincidence with Russian method and to a lesser extent with API 579/ASME FFS-1. In whole, all calculation methods demonstrate sufficient stability of results, which provides reliable operation of pipelines with defects.

COMPUTATIONAL AND EXPERIMENTAL STUDIES OF A LOW-EMISSION BURNER FOR A PERSPECTIVE TURBOJET ENGINE WITH THE COMPRESSION RATIO EXCEEDING 40

2020 ◽  
Author(s):  
M. A. Danilov ◽  
◽  
M. V. Drobysh ◽  
A. N. Dubovitsky ◽  
F. G. Markov ◽  
...  
Keyword(s):  
Compression Ratio ◽  
Experimental Studies ◽  
The Other ◽  
Aircraft Engines ◽  
Engine Efficiency ◽  
Other Hand ◽  
Turbojet Engine ◽  
Low Emission ◽  
Civil Aircraft ◽  
The One

Restrictions of emissions for civil aircraft engines, on the one hand, and the need in increasing the engine efficiency, on the other hand, cause difficulties during development of low-emission combustors for such engines.

scholarly journals Effort investment in uncontrollable situations: The moderating role of motivation toward closure

2021 ◽  
Vol 45 (2) ◽  
pp. 186-196
Author(s):  
Paulina Szwed ◽  
Małgorzata Kossowska ◽  
Marcin Bukowski
Keyword(s):  
Blood Pressure ◽  
Experimental Studies ◽  
The Other ◽  
Need For Closure ◽  
Extra Effort ◽  
Moderating Role ◽  
Energy Conservation Principle ◽  
Principle Of Energy Conservation ◽  
Investment Behaviour

AbstractAccording to the principle of energy-conservation principle, effort investment is usually reduced in situations that are perceived as uncontrollable. This is because when success is recognized as impossible, any effortful actions are no longer justified. However, we predicted that individual differences in uncertainty tolerance, i.e., the need for closure (NFC), may moderate effort investment in uncontrollable situations. We tested this prediction in two experimental studies in which we exposed participants with differing levels of NFC to uncontrollable events, and indexed effort through the assessment of systolic blood pressure (SBP) responses. As predicted, in the uncontrollability (vs. controllability) condition, effort investment decreased significantly among low- but not high-NFC participants. Since gaining certainty and achieving closure is not a critical epistemic goal for low-NFC individuals, exerting extra effort to gain certainty is therefore no longer justified. On the other hand, high-NFC participants do not withhold their efforts, as they are highly motivated to obtain certainty. These results may help to account for contradictory findings in effort-investment behaviour and add substantively to the literature concerning motivation toward closure.

Analysis of Polygonal Vortex Flows in a Cylinder with a Rotating Bottom

2021 ◽  
Vol 11 (3) ◽  
pp. 1348
Author(s):  
A. Rashkovan ◽  
S.D. Amar ◽  
U. Bieder ◽  
G. Ziskind
Keyword(s):  
Experimental Studies ◽  
Free Surface Flow ◽  
Careful Analysis ◽  
Numerical Approach ◽  
Surface Flow ◽  
Initial Water ◽  
Eddy Simulation ◽  
Disk Rotation ◽  
Inner Radius ◽  
Liquid Flows

The present paper provides a physically sound numerical modeling of liquid flows experimentally observed inside a vertical circular cylinder with a stationary envelope, rotating bottom and open top. In these flows, the resulting vortex depth may be such that the rotating bottom disk becomes partially exposed, and rather peculiar polygon shapes appear. The parameters and features of this work are chosen based on a careful analysis of the literature. Accordingly, the cylinder inner radius is 145 mm and the initial water height is 60 mm. The experiments with bottom disk rotation frequencies of 3.0, 3.4, 4.0 and 4.6 Hz are simulated. The chosen frequency range encompasses the regions of ellipse and triangle shapes as observed in the experimental studies reported in the literature. The free surface flow is expected to be turbulent, with the Reynolds number of O(105). The Large Eddy Simulation (LES) is adopted as the numerical approach, with a localized dynamic Subgrid-Scale Stresses (SGS) model including an energy equation. Since the flow obviously requires a surface tracking or capturing method, a volume-of-fluid (VOF) approach has been chosen based on the findings, where this method provided stable shapes in the ranges of parameters found in the corresponding experiments. Expected ellipse and triangle shapes are revealed and analyzed. A detailed character of the numerical results allows for an in-depth discussion and analysis of the mechanisms and features which accompany the characteristic shapes and their alterations. As a result, a unique insight into the polygon flow structures is provided.

On the question of the appointment of separate parameters of the roadheaders gathering-stars loading organs

2021 ◽  
pp. 90-93
Author(s):  
N.B. Afonina ◽  
A.V. Otrokov ◽  
G.Sh. Khazanovich
Keyword(s):  
Energy Consumption ◽  
Experimental Studies ◽  
The Other ◽  
Dynamic Loads ◽  
Selective Action ◽  
Side Edge ◽  
Fluidized State ◽  
High Dynamic ◽  
Loading Devices

Most modern roadheaders of selective action are equipped with loading devices with gathering-stars, which have a simpler drive design and increased reliability. As a result of the experimental studies carried out at SRSPU (NPI), it was found that under certain conditions, it is possible to transfer large lump material of a pile into a fluidized state, which reduces the energy consumption of material loading. An increase in the number of beams of the gathering-stars reduces the influence of the other parameters of the loader. Analysis of the process of interaction of the gathering-star’s beam with the receiving conveyor’s side edge to avoid jamming of the picking gathering-star by a lump of material with the implementation of high dynamic loads, it is necessary to set the gathering-beams at an angle of at least 60 degrees against rotation.

Influence of Temperature Fields on the Quality of Dried Wood Products

2021 ◽  
Vol 1038 ◽  
pp. 336-344
Author(s):  
Olena Pinchevska ◽  
Andriy Spirochkin ◽  
Denys Zavialov ◽  
Rostislav Oliynyk
Keyword(s):  
Experimental Studies ◽  
Wood Products ◽  
Temperature Fields ◽  
Drying Process ◽  
Wood Moisture ◽  
Adequate Model ◽  
Heating And Cooling ◽  
White Spots ◽  
The Cost ◽  
Wood Heating

The reasons of white spots appearance in the middle of oak timber are determined. These white spots reduce the cost of the lamina made of oak timbers - the front covering of floorboards. It is proposed to intensify the drying process by using oscillating drying schedules to avoid this defect. A method for calculating the duration of such drying is proposed. This method includes the peculiarities of heating and cooling periods kinetics of oak timbers with 25 mm and 30 mm thickness. The inexpediency of using the oscillation of the drying agent parameters in the range of wood moisture content below 20% has been established. An adequate model for calculating wood temperature and air humidity during wood heating and cooling periods has been developed using heat and mass transfer criteria and experimentally determined oak wood moisture conductivity coefficient. Based on the results of theoretical and experimental studies oscillating drying schedules of different thickness oak timbers are offered. Tests of the proposed schedules in industrial conditions showed no discoloration of the central layers of European oak (Quercus robur) timbers. The drying process duration was reduced by 1.5–2.4 times and energy consumption were reduced by 1.53 times.

Experimental Studies on the Uncomfortable Loudness Level

1971 ◽  
Vol 14 (2) ◽  
pp. 262-270 ◽  
Author(s):  
S. D. G. Stephens ◽  
C. M. B. Anderson
Keyword(s):  
Test Anxiety ◽  
Free Field ◽  
Experimental Studies ◽  
Stimulus Presentation ◽  
Normal Hearing ◽  
The Other ◽  
Personality Measures ◽  
Loudness Level

A number of experimental determinations of the uncomfortable loudness level (ULL) at 1000 Hz were made on several groups of normal-hearing subjects, using various methods of stimulus presentation and applying different personality measures to the subjects. The same mean levels were found for both earphone and free-field presentations. In experienced subjects the monaural-binaural difference was between 2.5 and 4 dB in different experiments. In naive subjects this difference was 6 dB. In two groups of subjects, ULL was found to be significantly negatively correlated with their test anxiety scores, but this correlation did not hold for the other two groups tested. Naive subjects showed little difference in intersubject variance with the manual or Bekesy presentation techniques.

scholarly journals Investigation of Beam Column Joint with Beam Weak in Shear under Monotonic Loading

2018 ◽  
Vol 7 (2.20) ◽  
pp. 182
Author(s):  
B Mounika ◽  
P Poluraju
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Main Parameter ◽  
Analytical Study ◽  
Experimental Studies ◽  
Element Model ◽  
The Other ◽  
Shear Reinforcement ◽  
Weak Beam ◽  
Column Joint

Earthquake affected structures, mostly failure occur at beam column joints (BCJ). BCJs are categorized according to their geometrical grouping as Interior, Exterior, and Corner joints. Exterior beam column joint (i.e., terminating the beam on one of the column faces) was the most vulnerable one with respect to the plane of loading. The present study aims at ductility behaviour of exterior BCJ with conventional reinforcement using the code IS 456-2000 and with special confining reinforcement using the Code IS 13920-2016. Four number of beam-column joint specimens are considered in which the first one is detailed as per IS 456-2000, the second one as per IS 13920-2016 and the other two with 50% and 30% reduction of shear reinforcement was provided while compared with the first specimen. It is mainly to satisfy the strong column-weak beam concept as the main parameter. The test was carried out on the loading frame with hinged conditions to the column both ends, and the load is applied at the tip of the beam. The experimental studies are proven with an analytical study carried out by finite element model by using ANSYS and disparate parameters are assessed both experimentally and analytically.  

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