A Numerical Approach to the Design of Sailing Yacht Masts

1991 ◽  
Author(s):  
Dario Boote ◽  
Mario Caponetto

In this paper a complete procedure for the design of sailing yacht rigs is presented. The procedure starts from the definition of the load model and the determination of the aerodynamic forces developed by sails and continues with the stress analysis of the rig in the non-linear domain. For the correct calculation of the sail forces a program has been realised by the authors on the basis of the lifting surface theory. For stress analysis, another dedicated program has been developed starting from a multipurpose finite element code operating in the non-linear domain, A peculiar characteristic of this procedure is that it can be run on a personal computer.

2018 ◽  
Vol 168 ◽  
pp. 02011 ◽  
Author(s):  
Marian Bojko ◽  
Milada Kozubková

Fluid flow in hydraulic systems, fittings, and piping causes hydraulic losses due to the change of flow direction and friction in the fluid. The main consequence of the resulting losses is the increase in the overall pressure gradient of the circuit. The paper is focused on the investigation of valve losses and the determination of resistance coefficients, the definition of which depends on the valve type. Methods of determination are of two types, i.e. experimental methods and mathematical methods. In the case of experimental methods, the procedures prescribed by the standards and regulations must be respected. Mathematical methods are related to defining an appropriate mathematical model and numerical approach. Both methods are applied to the ball valve and model verification is performed at the same time. The output of the thesis is the methodology for determination of resistance coefficients of valves with other diameters and other flowing media based on verified mathematical modeling.


1993 ◽  
Vol 37 ◽  
pp. 299-304
Author(s):  
Toshihiko Sasaki ◽  
Yukio Hirose

As known well, non-linear sin2ϕ diagrams are observed from materials having either steep gradients of residual stresses paralell to the surface normal of the specimen or tri-axial stress components. Many authors have reported on this problem for several processing such as polishing and grinding etc. The authors also obtained such non-linear data from an electro-plated zinc—nickel alloy. For these cases, the sin2ϕ method is inadequate for the stress evaluation. Much attention has been given to the stress analysis from about 1970s as compared to the X-ray elastic constants for this phenomenon.


1999 ◽  
Author(s):  
F. Fossati ◽  
G. Moschini ◽  
D. Vitalone

In the present paper a complete procedure which provides a rapid and low cost method for load evaluation in each rigging element of a sailboat like stays in the fore and aft direction, shrouds in the athwartship, sheets, halyards, and running back stays, will be described. Some results obtained using the proposed method will be shown relevant to an arbitrary chosen cruising sailing yacht.


2019 ◽  
Vol 21 (3) ◽  
pp. 219
Author(s):  
Muhammad Azzumar ◽  
Lukluk Khairiyati ◽  
Agah Faisal

<p>SNSU TK-BSN’s capability in determining the temperature coefficients of a standard resistor has been improved. The temperature coefficient is one of the important parameter in determining the definition of the standard resistor. Currently, the measurement result has been reported together with the measurement uncertainty. The determination itself is based on a numerical approach of Taylor Series Approximation (TSA) instead of based on a fitting to a certain equation. And by this determination, the uncertainty was calculated. The determination was validated by comparing the measurement result committed by SNSU TK-BSN to that of by the manufacturer. The equation for the temperature coefficient follows the parabolic equation with an alpha coefficient of -5.30 x 10-8 Ω/Ω/°C and beta coefficient of -4.70 x 10-8 Ω/Ω/°C<sup>2</sup>, with the respective uncertainties of 2.4 x 10-8 Ω/Ω/°C and 1.6x 10-8 Ω/Ω/°C<sup>2</sup>, respectively. SNSU TK-BSN measurement results in determining the temperature coefficient in agreement with the manufacturer's measurement results show an appropriate value. This correspondence has an equivalent degree of 0.20 for the alpha temperature coefficient and 0.27 for the beta coefficient.</p>


Author(s):  
Oldřich Sucharda ◽  
David Mikolášek ◽  
Jiří Brožovský

Abstract This paper deals with the determination of compressive strength of concrete. Cubes, cylinders and re-used test beams were tested. The concrete beams were first subjected to three-point or fourpoint bending tests and then used for determination of the compressive strength of concrete. Some concrete beams were reinforced, while others had no reinforcement. Accuracy of the experiments and calculations was verified in a non-linear analysis.


2016 ◽  
Vol 4 (2) ◽  
pp. 170 ◽  
Author(s):  
K. Eylem Özkaya Lassalle

The concept of failed state came to the fore with the end of the Cold War, the collapse of the USSR and the disintegration of Yugoslavia. Political violence is central in these discussions on the definition of the concept or the determination of its dimensions (indicators). Specifically, the level of political violence, the type of political violence and intensity of political violence has been broached in the literature. An effective classification of political violence can lead us to a better understanding of state failure phenomenon. By using Tilly’s classification of collective violence which is based on extent of coordination among violent actors and salience of short-run damage, the role played by political violence in state failure can be understood clearly. In order to do this, two recent cases, Iraq and Syria will be examined.


2020 ◽  
Vol 2020 (9) ◽  
pp. 29-33
Author(s):  
Sergey Bulatov

The paper purpose is the effectiveness estimation in the technological equipment use, taking into account its reliability and productivity for defective transmission units of buses. The problem consists in the determination of time to be spent on repair of bus transmission units taking into account technological equipment reliability. In the paper there is used a probabilistic method for the prediction bus transmission units, and also a method of the dynamics of averages which allow ensuring minimum of costs for units downtime during repair and equipment cost. The need for repair of transmission units (gear box) arises on an average after 650 hours, the average productivity of the bench makes 4.2 bus / hour. The bench fails on the average after 4600 hours of work, the average time of the bench makes 2 hours. In such a way the solution of the problem specified allows analyzing the necessity of time decrease for transmission unit repair to avoid long downtimes of buses in repair areas without negative impact upon high repair quality and safety during the further operation.


2020 ◽  
pp. 28-32
Author(s):  
V.S. Vanaev

Development of complex determination of parameters of jackhammers at bench tests is studied. The modern support of tests of jackhammers for the purpose of definition of their energy, vibration and noise indicators is considered. Descriptions of the SORP universal bench and UIPU measuring complex are given. Keywords jackhammer, bench, tests, processing object, energy indicators, impact energy, dynamic indicators [email protected]


2017 ◽  
Vol 31 (2) ◽  
pp. 156-162 ◽  
Author(s):  
O. V. Schneider

The article summarizes the main approaches in the definition of business valuation the economic entity. In the process of business valuation, taking into account the risks of financial and economic activities necessary to obtain information on what stage the owner implements the business will receive income. The most difficult task is the impossibility of accurate prediction in determining the level of income and the determination of a discount rate capitalization of future incomes due to the instability of the economy, both in the country and around the world.


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