scholarly journals HEAT SOURCE FOR TIG WELDING MODELLING

2021 ◽  
Vol 3 ◽  
pp. 348-356
Author(s):  
Manahil Tongov
Keyword(s):  
Heat Source ◽  
Concentration Factor ◽  
Tig Welding ◽  
Experimental Results ◽  
New Model ◽  
Heating Spot ◽  
Spot Radius ◽  
Calibration Parameters ◽  
Source Concentration

A new model of heat source applicable to TIG welding is proposed. The model uses three calibration parameters - efficiency, effective heating spot radius and heat source concentration factor. Based on the experimental results, the model was calibrated and the results obtained for the form of penetration were compared with the experimental ones.

scholarly journals Heat Source Characteristics of Ternary-Gas-Shielded Tandem Narrow-Gap GMAW

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1397 ◽  
Author(s):  
Cai ◽  
Dong ◽  
Lin ◽  
Murphy ◽  
Fan ◽  
...  
Keyword(s):  
Heat Source ◽  
Concentration Factor ◽  
Fluid Dynamic ◽  
Source Distribution ◽  
Narrow Gap ◽  
Shielding Gas ◽  
Maximum Heat ◽  
Source Characteristics ◽  
Heat Efficiency ◽  
Source Concentration

: The characteristics of the welding heat source for tandem narrow-gap gas metal arc welding are examined for different ternary shielding gas (Ar-CO2-He) compositions. Results of previous calculations of arc properties for bead-on-plate geometry are adapted to the narrow-gap geometry to predict these characteristics. The heat source concentration factor decreases and the maximum heat flux density increases as the helium content increases, which leads to an increased welding heat efficiency. Addition of CO2 up to around 10% also increases the heat efficiency. When the CO2 content exceeds 10%, the heat source concentration factor increases significantly and the heat efficiency decreases. The shielding gas composition also affects the heat source distribution. The heat source characteristics are applied to a computational fluid dynamic model of the weld pool to predict the weld shape, and the predictions are verified by experiment. The results indicate that the appropriate addition of helium to the shielding gas can increase the heat transferred to the peripheral regions of the arc and increase the sidewall penetration.

New model of dielectric strength of Debye relaxation in monohydroxy alcohols

2019 ◽  
Vol 33 (26) ◽  
pp. 1950313
Author(s):  
Li-Na Wang ◽  
Xing-Yu Zhao ◽  
Yi-Neng Huang
Keyword(s):  
Experimental Data ◽  
Exact Solution ◽  
High Temperature ◽  
Ising Model ◽  
Dielectric Spectroscopy ◽  
Dielectric Strength ◽  
Experimental Results ◽  
Debye Relaxation ◽  
New Model ◽  
Model Predictions

The Debye relaxation of dielectric spectroscopy exists extensively in monohydroxy alcohols, and the existing theory of the dielectric strength is obviously inconsistent with the experimental results. In this paper, we propose an Ising model of infinite free-rotating pseudospin chains and get the exact solution of the dielectric strength versus temperature. The model predictions are qualitatively consistent with the experimental results, especially the crossover from the low to the high-temperature Curie–Weiss law. The quantitative comparisons indicate that the model predictions can agree well with the experimental data below 250 K.

Speech Enhancement Using Heterogeneous Information

2018 ◽  
Vol 10 (3) ◽  
pp. 46-59
Author(s):  
Yan Xiong ◽  
Fang Xu ◽  
Qiang Chen ◽  
Jun Zhang
Keyword(s):  
Speech Enhancement ◽  
Experimental Results ◽  
Noisy Environments ◽  
Heterogeneous Information ◽  
New Model ◽  
Model Based ◽  
Single Stream

This article describes how to use heterogeneous information in speech enhancement. In most of the current speech enhancement systems, clean speeches are recovered only from the signals collected by acoustic microphones, which will be greatly affected by the acoustic noises. However, heterogeneous information from different kinds of sensors, which is usually called the “multi-stream,” are seldom used in speech enhancement because the speech waveforms cannot be recovered from the signals provided by many kinds of sensors. In this article, the authors propose a new model-based multi-stream speech enhancement framework that can make use of the heterogeneous information provided by the signals from different kinds of sensors even when some of them are not directly related to the speech waveform. Then a new speech enhancement scheme using the acoustic and throat microphone recordings is also proposed based on the new speech enhancement framework. Experimental results show that the proposed scheme outperforms several single-stream speech enhancement methods in different noisy environments.

scholarly journals A New Model of RGB-D Camera Calibration Based On 3D Control Field

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5082 ◽  
Author(s):  
Zhang ◽  
Huang ◽  
Zhao
Keyword(s):  
3D Reconstruction ◽  
State Of The Art ◽  
Calibration Model ◽  
Control Field ◽  
New Model ◽  
Depth Images ◽  
Extrinsic Parameters ◽  
Relationship Model ◽  
Relative Pose ◽  
Calibration Parameters

With extensive application of RGB-D cameras in robotics, computer vision, and many other fields, accurate calibration becomes more and more critical to the sensors. However, most existing models for calibrating depth and the relative pose between a depth camera and an RGB camera are not universally applicable to many different kinds of RGB-D cameras. In this paper, by using the collinear equation and space resection of photogrammetry, we present a new model to correct the depth and calibrate the relative pose between depth and RGB cameras based on a 3D control field. We establish a rigorous relationship model between the two cameras; then, we optimize the relative parameters of two cameras by least-squares iteration. For depth correction, based on the extrinsic parameters related to object space, the reference depths are calculated by using a collinear equation. Then, we calibrate the depth measurements with consideration of the distortion of pixels in depth images. We apply Kinect-2 to verify the calibration parameters by registering depth and color images. We test the effect of depth correction based on 3D reconstruction. Compared to the registration results from a state-of-the-art calibration model, the registration results obtained with our calibration parameters improve dramatically. Likewise, the performances of 3D reconstruction demonstrate obvious improvements after depth correction.

A harmonic drive model considering geometry and internal interaction

2016 ◽  
Vol 231 (4) ◽  
pp. 728-743 ◽  
Author(s):  
Chuang Zou ◽  
Tao Tao ◽  
Gedong Jiang ◽  
Xuesong Mei ◽  
Junhui Wu
Keyword(s):  
Ball Bearing ◽  
Experimental Results ◽  
Torsional Stiffness ◽  
Harmonic Drive ◽  
Low Velocity ◽  
New Model ◽  
Internal Interaction ◽  
Drive Systems ◽  
Assembly Error ◽  
Drive Model

A new harmonic drive model considering the geometry, internal interactions and assembly error of key parts is proposed in this paper. In this model, a single tooth pair is used to represent the transmission mechanism of harmonic drive. The meshing stiffness between the flexspline and the circular spline, the torsional stiffness of the flexspline cylinder, and the radial stiffness of the thin-walled ball bearing are included and formulated. The kinematic error is fitted using a low-velocity test, and its generating mechanism is analysed. The friction of the harmonic drive is formulated at the tooth meshing section and at the ball bearing, where its parameters are identified based on experimental results. Based on the new model, velocity step simulations are conducted. For comparison, velocity step experiments at eight different velocities from 60 to 3000 r/min are performed, and the simulation results are in good agreement with the experimental results. The new model reveals the dynamic behaviour of the harmonic drive system; therefore, it will be useful for the dynamic design and precision control of harmonic drive systems.

ATIG Welding of Duplex Steel

2008 ◽  
Vol 589 ◽  
pp. 49-54 ◽  
Author(s):  
Tamás Sándor
Keyword(s):  
Weld Joint ◽  
Marangoni Effect ◽  
Tig Welding ◽  
Experimental Results ◽  
Grain Structure ◽  
High Productivity ◽  
Duplex Steel ◽  
Effect Theory ◽  
Advantageous Effect

The ATIG welding which is the high productivity version of conventional TIG welding, parallel with productivity increasing has some advantageous effect both on HAZ and weld joint grain structure. In this paper the effect of ATIG welding on austenite/ferrite ratio in duplex steel will be represented with experimental results performed on 8 mm thick 2205 type duplex steel. As collateral benefit through these results new evidences are originated to prove the “reversed Marangoni effect” theory.

A New Model to Describe Yield Surface Distortion Based on the Baltov and Sawczuk’s Model

2012 ◽  
Author(s):  
A. Nayebi ◽  
H. Rokhgireh
Keyword(s):  
Yield Surface ◽  
Kinematic Hardening ◽  
Experimental Results ◽  
Surface Model ◽  
New Model ◽  
Surface Distortion ◽  
Loading Direction ◽  
Reverse Loading ◽  
Reversed Loading ◽  
Yield Surface Distortion

In the present study Baltov and Sawczuk’s yield surface model is modified to represent compatible results with experimental observations. The proposed yield surface is determined during tension-torsion loading by considering kinematic hardening model and monotonic loading paths. The experimental results represent the nosed and flattened region in the loading and reverse loading direction respectively. The nosed region is dominant in tension than in torsion. The cross-effect is negligible in the small plastic strain amount. The Baltov and Sawczuk’s yield surface has nosed and flattened regions in both loading and reversed loading directions for negative and positive added material parameter respectively. Thus the elliptic Baltov and Sawczuk’s yield surface is modified by changing the sign of this parameter continuously from loading to reverse loading direction and the needed relations of the new model are obtained. The new model was able to predict properly the shape of yield surface. The experimental results compare well with the new model yield surface distortion predictions.

scholarly journals Fusing website usability and search engine optimisation

2014 ◽  
Vol 16 (1) ◽  
Author(s):  
Eugene B. Visser ◽  
Melius Weideman
Keyword(s):  
Search Engine ◽  
Search Engines ◽  
Experimental Results ◽  
New Model ◽  
High Ranking ◽  
Website Usability ◽  
The Individual

Background: Most websites, especially those with a commercial orientation, need a high ranking on a search engine for one or more keywords or phrases. The search engine optimisation process attempts to achieve this. Furthermore, website users expect easy navigation, interaction and transactional ability. The application of website usability principles attempts to achieve this. Ideally, designers should achieve both goals when they design websites.Objectives: This research intended to establish a relationship between search engine optimisation and website usability in order to guide the industry. The authors found a discrepancy between the perceived roles of search engines and website usability.Method: The authors designed three test websites. Each had different combinations of usability, visibility and other attributes. They recorded and analysed the conversions and financial spending on these experimental websites. Finally, they designed a model that fuses search engine optimisation and website usability.Results: Initially, it seemed that website usability and search engine optimisation complemented each other. However, some contradictions between the two, based on content, keywords and their presentation, emerged. Industry experts do not acknowledge these contradictions, although they agree on the existence of the individual elements. The new model highlights the complementary and contradictory aspects.Conclusion: The authors found no evidence of any previous empirical experimental results that could confirm or refute the role of the model. In the fast-paced world of competition between commercial websites, this adds value and originality to the websites of organisations whose websites play important roles.

Experimental Results of an Ammonia-Water Mixture Turbine System: Effectiveness With a Low Temperature Heat Source

2004 ◽  
Author(s):  
Keisuke Takeshita ◽  
Kouji Morimoto ◽  
Yoshiharu Amano ◽  
Takumi Hashizume
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Steam Turbine ◽  
Back Pressure ◽  
Experimental Results ◽  
Water Mixture ◽  
Heat Sources ◽  
Sensible Heat ◽  
Ammonia Water ◽  
Temperature Heat

This paper presents an experimental investigation of the effectiveness of an AWM (Ammonia-Water Mixture) turbine system with low temperature heat sources. The AWM turbine system (AWMTS) features Kalina cycle technology, namely, it employs an ammonia-water mixture as the working fluid and includes a separation / absorption process of NH3-H2O. Since AWM is a non-azeotropic mixture, its temperature changes during evaporation and condensation. This behavior gives AWMTS the advantage of heat recovery from a sensible heat source such as exhaust gas. It is known that an AWMTS can generate more power than a Rankine cycle system from 250–650°C sensible heat sources. The authors constructed a 70 KW-experimental facility and investigated the practical applications of AWMTS. It is located at the bottoming stage below a conventional combined cycle composed of a gas turbine and a steam turbine. Its heat source is the exhaust steam from a back pressure steam turbine at the middle stage of the system. The experiment was carried out with changing the back pressure of the steam turbine. The experimental results show that power generation is possible from 138 to 162 °C heat source steam.

scholarly journals A Preference Model on Adaptive Affinity Propagation

2018 ◽  
Vol 8 (3) ◽  
pp. 1805 ◽  
Author(s):  
Rina Refianti ◽  
Achmad Benny Mutiara ◽  
Asep Juarna ◽  
Adang Suhendra
Keyword(s):  
Data Clustering ◽  
Message Passing ◽  
Clustering Algorithms ◽  
Experimental Results ◽  
Data Sets ◽  
Similarity Matrix ◽  
Preference Model ◽  
New Model ◽  
Data Points ◽  
Scanning Algorithm

In recent years, two new data clustering algorithms have been proposed. One of them isAffinity Propagation (AP). AP is a new data clustering technique that use iterative message passing and consider all data points as potential exemplars. Two important inputs of AP are a similarity matrix (SM) of the data and the parameter ”preference” p. Although the original AP algorithm has shown much success in data clustering, it still suffer from one limitation: it is not easy to determine the value of the parameter ”preference” p which can result an optimal clustering solution. To resolve this limitation, we propose a new model of the parameter ”preference” p, i.e. it is modeled based on the similarity distribution. Having the SM and p, Modified Adaptive AP (MAAP) procedure is running. MAAP procedure means that we omit the adaptive p-scanning algorithm as in original Adaptive-AP (AAP) procedure. Experimental results on random non-partition and partition data sets show that (i) the proposed algorithm, MAAP-DDP, is slower than original AP for random non-partition dataset, (ii) for random 4-partition dataset and real datasets the proposed algorithm has succeeded to identify clusters according to the number of dataset’s true labels with the execution times that are comparable with those original AP. Beside that the MAAP-DDP algorithm demonstrates more feasible and effective than original AAP procedure.

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