Prediction of wrinkle types in tube hydroforming under pulsating hydraulic pressure with axial feeding

2016 ◽  
Vol 231 (15) ◽  
pp. 2810-2821 ◽  
Author(s):  
Yang Lianfa ◽  
Hu Zhulin ◽  
He Yulin
Keyword(s):  
Tube Hydroforming ◽  
Prediction Method ◽  
Prediction Methods ◽  
Hydraulic Pressure ◽  
Axial Feeding

Wrinkling frequently occurs in tube hydroforming, resulting in an undesirable loss of quality and precision of the formed workpiece, and is generally regarded as a defect. However, wrinkling can also be utilised to improve the formability of tubular materials if it can be gradually reduced or even flattened in the follow-up tube hydroforming. For this reason, wrinkling is classified into two types—harmful wrinkle and useful wrinkle. In this paper, two prediction methods, geometry-based prediction method and mechanics-based prediction method, are proposed to predict the wrinkle type occurring in tube hydroforming under pulsating hydraulic pressure with axial feeding. Then, the corresponding tube hydroforming experiments are presented, which were carried out to validate the two proposed prediction methods by comparing the deformation and wrinkling behaviours. Finally, the characteristics of the two approaches are compared and discussed. The results indicate that the wrinkle type occurring in the present tube hydroforming experiments under pulsating hydraulic pressure with axial feeding could be predicted by both prediction methods, with the geometry-based prediction method providing more accuracy than the mechanics-based prediction method.

Reviews and a New Angle of β Coefficient Prediction Method

2013 ◽  
Vol 709 ◽  
pp. 687-690
Author(s):  
Jun Hang Liu
Keyword(s):  
Decision Making ◽  
Risk Management ◽  
Capital Market ◽  
Three Dimensional ◽  
Prediction Method ◽  
Prediction Methods ◽  
Nineteen Seventies ◽  
Entropy Measurement ◽  
Accuracy Of Prediction

The β coefficient is one of the key parameters in the capital market and risk management, and is the important decision-making basis for the stakeholders in the market economy. But from the nineteen seventies, β coefficient is unstable which has been confirmed by a number of literatures, therefore the follow-up researchers have always focused on searching for the better method to improve the accuracy of prediction of the β coefficient. This paper reviewed the existing literature about prediction methods for the β coefficient, and then gave a new method of forecasting the β coefficient-three dimensional entropy measurement.

scholarly journals Tabel Prediksi Moyers dan Sitepu terhadap Lebar Mesiodistal Gigi Permanen Pengganti pada Etnis Arab Yaman di Surabaya

2020 ◽  
Vol 8 (1) ◽  
pp. 42
Author(s):  
Firyal Baktir ◽  
Dwi Prijatmoko ◽  
Masniari Novita
Keyword(s):  
Key Words ◽  
Prediction Method ◽  
Mixed Dentition ◽  
Prediction Methods ◽  
Tooth Size ◽  
Cross Sectional ◽  
Caucasian Race ◽  
Size Discrepancy ◽  
Tooth Size Discrepancy ◽  
Cross Sectional Design

There are several methods of analizing tooth size discrepancy in orthodontics include prediction methods for mixed dentition. Prediction method of Moyers and Sitepu most commonly used although both were obtained from 2 different races, Caucasian and Deutromelayu. Yemeni ethnic is one of the ethnic groups settled in Indonesia which descendants of the Caucasian race. The aim of the study was to observed the suitable prediction table for Yemeni ethnic. It was an observasional analitics study consist of 40 samples with cross sectional design. The results showed that slight difference for prediction of Moyers on the maxilla (1.02) and prediction of Sitepu on the mandibula (0.11). As conclusion, the most suitable predicition method for Yemeni ethnic is Moyers’s method for maxila and sitepu’s method for mandibula.   Key words: mesiodistal width permanen teeth, Moyers method, Sitepu method, Yemeni Etnic

scholarly journals Follow-up: Prospective compound design using the ‘SAR Matrix’ method and matrix-derived conditional probabilities of activity

F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 75 ◽  
Author(s):  
Disha Gupta-Ostermann ◽  
Yoichiro Hirose ◽  
Takenao Odagami ◽  
Hiroyuki Kouji ◽  
Jürgen Bajorath
Keyword(s):  
Related Compound ◽  
Chemical Space ◽  
Prediction Method ◽  
Previous Method ◽  
Conditional Probabilities ◽  
Activity Prediction ◽  
Structure Activity ◽  
Related Series ◽  
Compound Series

In a previous Method Article, we have presented the ‘Structure-Activity Relationship (SAR) Matrix’ (SARM) approach. The SARM methodology is designed to systematically extract structurally related compound series from screening or chemical optimization data and organize these series and associated SAR information in matrices reminiscent of R-group tables. SARM calculations also yield many virtual candidate compounds that form a “chemical space envelope” around related series. To further extend the SARM approach, different methods are developed to predict the activity of virtual compounds. In this follow-up contribution, we describe an activity prediction method that derives conditional probabilities of activity from SARMs and report representative results of first prospective applications of this approach.

MDAPlatform: a Component-based Platform for Constructing and Assessing miRNA-disease association Prediction Methods

2021 ◽  
Vol 16 ◽  
Author(s):  
Yayan Zhang ◽  
Guihua Duan ◽  
Cheng Yan ◽  
Haolun Yi ◽  
Fang-Xiang Wu ◽  
...  
Keyword(s):  
Computational Models ◽  
Critical Role ◽  
Prediction Method ◽  
Disease Association ◽  
Prediction Methods ◽  
Comparison Results ◽  
Disease Associations ◽  
Pros And Cons ◽  
Clinical Drugs ◽  
Validation Experiments

Background: Increasing evidence has indicated that miRNA-disease association prediction plays a critical role in the study of clinical drugs. Researchers have proposed many computational models for miRNA-disease prediction. However, there is no unified platform to compare and analyze the pros and cons or share the code and data of these models. Objective: In this study, we develop an easy-to-use platform (MDAPlatform) to construct and assess miRNA-disease association prediction method. Methods: MDAPlatform integrates the relevant data of miRNA, disease and miRNA-disease associations that are used in previous miRNA-disease association prediction studies. Based on the componentized model, it develops differet components of previous computational methods. Results: Users can conduct cross validation experiments and compare their methods with other methods, and the visualized comparison results are also provided. Conclusion: Based on the componentized model, MDAPlatform provides easy-to-operate interfaces to construct the miRNA-disease association method, which is beneficial to develop new miRNA-disease association prediction methods in the future.

Resistance Prediction of Planing Hulls: State of the Art

1993 ◽  
Vol 30 (04) ◽  
pp. 297-307
Author(s):  
John M. Almeter
Keyword(s):  
State Of The Art ◽  
Prediction Method ◽  
Prediction Methods ◽  
Resistance Prediction ◽  
Good For

There are literally dozens of different ways that the boat designer can predict the resistance of planing hulls. The term planing hull is used generically to describe the majority of hard chine boats being built today. No single prediction method is good for all types of planing hulls. Some methods can be relied on to give good predictions for certain boats and other methods can't be relied upon at all. This paper is meant as a reference for designers in selecting resistance prediction methods for planing hulls. It describes numerous resistance prediction methods and gives their variable ranges and the type of planing hulls they are based on or are intended for. Inherent problems or limitations of the methods are stated. The concept of hull shape, which is often neglected in resistance prediction, and its important role are discussed.

scholarly journals Comparison of Prediction Methods for Axial Strength of Grouted Connections with Shear Keys

2020 ◽  
Vol 10 (6) ◽  
pp. 1942
Author(s):  
You Xianhui ◽  
Wu Zhaoqi ◽  
Chen Zehao
Keyword(s):  
Health And Safety ◽  
Prediction Method ◽  
American Petroleum Institute ◽  
Experimental Results ◽  
Offshore Wind ◽  
Prediction Methods ◽  
Compression Tests ◽  
Axial Strength ◽  
Wide Range ◽  
Shear Keys

Grouted connections are commonly used in marine engineering, especially on oil platforms, cross-sea bridges, and offshore wind power turbines. The prediction methods for axial carrying capacity of grouted connections with shear keys and their application ranges in current codes were analyzed in this paper. The calculated results by using different codes were compared based on a practical grouted connection between steel piles and the jacket foundation of a wind turbine. The research team conducted axial compression tests on seven specimens, collected a wide range of experimental results to establish a database, and finally compared the standard calculation results with the experimental results. The study indicates that the axial strength of grouted connections predicted by different methods is distinct. The calculation formula of the British Health and Safety Executive (HSE, 2002) has obvious limitations; specifically, with increased shear keys, strength is overestimated, resulting in insecure design outcome of structures. The results calculated by the Norwegian Det Norske Veritas (DNV, 2013) are generally consistent with the experimental results, in which the reduction effect of multiple shear keys was considered. The prediction method of the American Petroleum Institute (API, 2007), which undervalues the bearing performance of connections, is excessively conservative. The method of the combined Norwegian and German Det Norske Veritas–Germanischer Lloyd (DNV-GL, 2016) has wider applicability and is safe, reliable, and economical.

A state-of-the-art review on wind power deterministic prediction

2020 ◽  
pp. 0309524X2094120 ◽  
Author(s):  
Zhongda Tian
Keyword(s):  
Wind Power ◽  
Prediction Method ◽  
Scale Model ◽  
Ensemble Prediction ◽  
Prediction Methods ◽  
Power Prediction ◽  
Continuous Growth ◽  
Advantages And Disadvantages ◽  
Wind Power Prediction ◽  
The Impact

With the continuous growth of wind power access capacity, the impact of intermittent and volatile wind power generation on the grid is becoming more and more obvious, so the research of wind power prediction method has been widely concerned. Accurate wind power prediction can provide necessary support for the power grid dispatching, combined operation of generating units, operation, and maintenance of wind farms. According to the existing wind power prediction methods, the wind power prediction methods are systematically classified according to the time scale, model object, and model principle of prediction. The physical methods, statistical methods include single and ensemble prediction methods related to wind power prediction are introduced in detail. The error evaluation indicator of the prediction method is analyzed, and the advantages and disadvantages of each prediction method and its applicable occasions are given. At the same time, in view of the existing problems in the wind power prediction method, the corresponding improvement plan is put forward. Finally, this article points out that the research is needed for wind power prediction in the future.

The Influence of Friction on Forming Accuracy of Tubular Parts by Hydroforming with Radial Crushing

2011 ◽  
Vol 328-330 ◽  
pp. 1386-1390 ◽  
Author(s):  
Lian Fa Yang ◽  
Pan Lei ◽  
Chen Guo
Keyword(s):  
Cross Section ◽  
Circular Tube ◽  
Tube Hydroforming ◽  
Loading Path ◽  
Hydraulic Pressure ◽  
Forming Quality ◽  
Tubular Part ◽  
Forming Accuracy ◽  
Constant Maximum

Forming accuracy is one of the important indicators to evaluate the forming quality of a tubular part by tube hydroforming. However, shape asymmetry on cross-section of tubular part produced by hydroforming with radial crushing (THFRC) inevitably appears due to the friction between the die and the part. In this paper, a circular tube is formed into a square cross-section one by THFRC under the various loading paths and the influence of friction on the forming accuracy of cross-section of the bulged parts is analyzed by using numerical simulation. The results show that the larger the tube is expended to, the lower the forming accuracy is under the identical coefficients of friction (COF); the larger the COF value is, the lower the forming accuracy is under a constant maximum hydraulic pressure. In a word, a reasonable loading path and a low COF value can observably improve the forming accuracy of the bulged tube.

The Hydroforming of Micro-Square Tubes With Non-Equal Section and Dendritic Shape

2006 ◽  
Vol 505-507 ◽  
pp. 739-744
Author(s):  
Yuan Chuan Hsu ◽  
Tung Sheng Yang ◽  
J.L. Wu ◽  
Y.X. Chen
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Tube Hydroforming ◽  
Simulation Technique ◽  
Hydraulic Pressure ◽  
Micro Forming ◽  
Wall Thinning ◽  
Element Simulation ◽  
Feeding Speed ◽  
Dendritic Shape

Currently, tube hydroforming and metal micro-forming technique have emerged as the attractive and important developing tendencies in industry. Hence, in this study, the finite element simulation technique was employed to investigate the micro-hydroforming for making the micro-square tube with non-equal section and dendritic shape from square tube. Results of the current study show that the deformation of micro-square tube can be effectively analyzed by finite element simulation. The bulging and wall thinning of the tube are severely influenced not only by the internal hydraulic pressure but also by the punch axial feeding speed.

Prediction of Mine Gas Emission Based on Time Series Analysis

2012 ◽  
Vol 616-618 ◽  
pp. 450-454 ◽  
Author(s):  
Hai Dong Meng ◽  
Dong Yuan Zang ◽  
Yu Chen Song
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Prediction Method ◽  
Ar Model ◽  
Prediction Methods ◽  
Gas Emission ◽  
Gas Concentration ◽  
Series Analysis ◽  
Mine Gas

Because the variation of mine gas concentration is influenced by various factors, so it’s impossible for traditional prediction methods of mine gas emission to include all the factors. To solve the problem, the paper proposed a prediction method of mine gas emission based on AR model of time series analysis. The experiment results indicated that the method can predict mine gas emission accurately.

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