scholarly journals The Area Method in the Wolfram Language

2021 ◽  
Vol 352 ◽  
pp. 64-76
Author(s):  
Jack Heimrath
Keyword(s):  
Area Method

scholarly journals An experimental method to determine the intralaminar fracture toughness of high-strength carbon-fibre reinforced composite aerostructures

2018 ◽  
Vol 122 (1255) ◽  
pp. 1352-1370 ◽  
Author(s):  
H. Liu ◽  
B.G. Falzon ◽  
G. Catalanotti ◽  
W. Tan
Keyword(s):  
Fracture Toughness ◽  
Tensile Strength ◽  
Crack Tip ◽  
Damage Mechanism ◽  
Calibration Method ◽  
Compact Tension ◽  
Tensile Fracture ◽  
High Tensile Strength ◽  
Physical Test ◽  
Area Method

ABSTRACTCarbon fibres with high tensile strength are being increasingly utilised in the manufacture of advanced composite aerostructures. A Modified Compact Tension (MCT) specimen is often deployed to measure the longitudinal intralaminar fracture toughness but a high tensile strength often leads to premature damage away from the crack tip. We present an approach whereby the MCT specimen is supported by external fixtures to prevent premature damage. In addition, we have developed a novel measurement technique, based on the fibre failure strain and C-scanning, to determine the crack length in the presence of surface sublaminate delamination which masks the crack tip location. A set of cross-ply specimens, with a ((90/0)s)4 layup, were manufactured from an IMS60/epoxy composite system Two different data reduction schemes, compliance calibration and the area method, are used to determine the fibre-dominated initiation and propagation intralaminar fracture toughness values. Propagation values of fracture toughness were measured at 774.9 ± 5.2% kJ/m2 and 768.5 ± 4.1% kJ/m2, when using the compliance calibration method and the area method, respectively. Scanning Electron Microscopy (SEM) is carried out on the fracture surface to obtain insight into the damage mechanism of high-tensile-strength fibre-reinforced unidirectional composites. The measured tensile fracture toughness value is used in a fully validated computational model to simulate the physical test.

The Mathematical Model of Welding Process Comparative Study of Identification Method

2012 ◽  
Vol 472-475 ◽  
pp. 2241-2244 ◽  
Author(s):  
Jun Feng Wu ◽  
Jing Huang
Keyword(s):  
Weld Pool ◽  
Academic Research ◽  
Welding Process ◽  
Least Square Method ◽  
Mathematic Model ◽  
Least Square ◽  
Complex Object ◽  
Strong Nonlinearity ◽  
Area Method ◽  
Pulsed Gtaw

The dynamic process of the weld pool is a high complex object with strong nonlinearity, mult-variable coupling and a mount of stochastic and uncertain factors. It is very difficult to obtain an analysis mathematic model of weld pool dynamics. Pulsed Gas Tungsten Arc Welding (GTAW) is an important metal’s welding technology, which has been widely applied in the aerospace and manufacturing areas. Therefore, the dynamic characteristic of the welding process has always been hot and difficult in the field of academic research and engineering applications. In order to solve the difficulties of modeling and controlling of nonlinear system, this paper investigates the dynamic characters of the pulsed GTAW from the classic control systems. It obtains the SISO transfer function model by the area method and least square method. The results of simulation experiment show that the area method is better between the two methods.

Quantification of mitral regurgitation by colour flow Doppler imaging — value of the ‘proximal isovelocity surface area’ method

1993 ◽  
Vol 42 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Georg Grossmann ◽  
Martin Giesler ◽  
Arnold Schmidt ◽  
Matthias Kochs ◽  
Siegfried Wieshammer ◽  
...  
Keyword(s):  
Mitral Regurgitation ◽  
Surface Area ◽  
Doppler Imaging ◽  
Area Method ◽  
Proximal Isovelocity Surface Area ◽  
Colour Flow

A New Equal Area Method to Calculate and Represent Physiologic, Anatomical, and Alveolar Dead Spaces

2006 ◽  
Vol 104 (4) ◽  
pp. 696-700 ◽  
Author(s):  
Yongquan Tang ◽  
Martin J. Turner ◽  
A Barry Baker
Keyword(s):  
Carbon Dioxide ◽  
Dead Space ◽  
Graphical Method ◽  
Mean Difference ◽  
Equal Area ◽  
Area Method ◽  
Physiologic Dead Space ◽  
Anatomical Dead Space ◽  
The Mean ◽  
The Difference

Background Physiologic dead space is usually estimated by the Bohr-Enghoff equation or the Fletcher method. Alveolar dead space is calculated as the difference between anatomical dead space estimated by the Fowler equal area method and physiologic dead space. This study introduces a graphical method that uses similar principles for measuring and displaying anatomical, physiologic, and alveolar dead spaces. Methods A new graphical equal area method for estimating physiologic dead space is derived. Physiologic dead spaces of 1,200 carbon dioxide expirograms obtained from 10 ventilated patients were calculated by the Bohr-Enghoff equation, the Fletcher area method, and the new graphical equal area method and were compared by Bland-Altman analysis. Dead space was varied by varying tidal volume, end-expiratory pressure, inspiratory-to-expiratory ratio, and inspiratory hold in each patient. Results The new graphical equal area method for calculating physiologic dead space is shown analytically to be identical to the Bohr-Enghoff calculation. The mean difference (limits of agreement) between the physiologic dead spaces calculated by the new equal area method and Bohr-Enghoff equation was -0.07 ml (-1.27 to 1.13 ml). The mean difference between new equal area method and the Fletcher area method was -0.09 ml (-1.52 to 1.34 ml). Conclusions The authors' equal area method for calculating, displaying, and visualizing physiologic dead space is easy to understand and yields the same results as the classic Bohr-Enghoff equation and Fletcher area method. All three dead spaces--physiologic, anatomical, and alveolar--together with their relations to expired volume, can be displayed conveniently on the x-axis of a carbon dioxide expirogram.

scholarly journals Using the Fusion Proximal Area Method and Gravity Method to Identify Areas with Physician Shortages

PLoS ONE ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. e0163504 ◽  
Author(s):  
Xuechen Xiong ◽  
Chao Jin ◽  
Haile Chen ◽  
Li Luo
Keyword(s):  
Gravity Method ◽  
Area Method ◽  
Physician Shortages

scholarly journals Ranking Fuzzy Numbers with an Area Method Using Circumcenter of Centroids

2013 ◽  
Vol 5 (1) ◽  
pp. 3-18 ◽  
Author(s):  
P. Phani Bushan Rao ◽  
N. Ravi Shankar
Keyword(s):  
Fuzzy Numbers ◽  
Area Method

Study on a Large Opening in a Pressure Vessel

2011 ◽  
Vol 308-310 ◽  
pp. 58-61
Author(s):  
Wei Wang ◽  
Jing Bao Shi ◽  
Ming Fu Luo ◽  
Yu Fang Wang
Keyword(s):  
Numerical Calculation ◽  
Stress Concentration ◽  
Pressure Vessel ◽  
Mechanical Characteristics ◽  
Inside Surface ◽  
Reinforcing Effect ◽  
Area Method ◽  
Pressure Area ◽  
Opening Ratio ◽  
Large Opening

In this paper ,we ared study on the reinforcement of a large opening with which the opening ratio is (W)0.8 with numerical calculation. We analyzed the Mechanical characteristics of opened shell It shows the stress concentration is seen clearly on point A which is between Connecting Inside surface of pipe and shell ,and point B, which is between Connecting outside surface of pipe and shell. And the stress concentration on point A is more than on point A when the opening ration(W) is 0.8.And it is calculated reinforcing effect and analyze the limitation when the opening ration by pressure area method（Referred to PAM）.It is obtained the limitation of PAM by comparing numerical calculation to PAM.

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