A Review of the Ninth International Conference on the Stability of Ships and Ocean Vehicles (STAB 2006)

2008 ◽  
Vol 45 (03) ◽  
pp. 147-156
Author(s):  
Marcelo A. S. Neves ◽  
Vadim Belenky

The paper gives a brief review of the papers presented at the Ninth International Conference on Stability of Ships and Ocean Vehicles that was held on September 25 to 29, 2006 in Rio de Janeiro, Brazil. The review covers the following stability-related subjects: stability regulations, intact stability, wind and waves, damage stability, stability in operation, stability of high-speed craft, and offshore vehicles.

2001 ◽  
Vol 38 (01) ◽  
pp. 1-8
Author(s):  
Vadim L. Belenky

A brief review is given of the papers presented at the 7th International Conference on the Stability of Ships and Ocean Vehicles, held 7–12 February 2000 in Launceston, Australia. The review covers the following stability-related subjects: human factors, stability standards, operational aspects, influence of water on deck, damage stability, stability in following and quartering seas, stability of high-speed craft and sailing yachts, nonlinear dynamics of ships, test procedures, roll stabilization and cargo shift, waves and the environment, rolling in beam seas and stability of particular types of ships.


2005 ◽  
Vol 42 (01) ◽  
pp. 21-30
Author(s):  
Luis Pérez Rojas ◽  
Vadim L. Belenky

This paper briefly reviews the papers presented at the 8th International Conference on Stability of Ship and Ocean Vehicles that was held September 15–19, 2003, in Madrid, Spain. The review covers the following stability-related subjects: history, accident investigation, water on deck, extreme weather effects, stability of unconventional vessels, design for safety, damage stability, including large passenger vessels, para-metric roll, regulatory aspects, environmental modeling, human factors, safety in operations, nonlinear dynamics, unconventional problems, intact stability, antirolling devices, fishing vessels stability, and ship motion in waves, as well as several workshops on intact stability, damage stability, fishing vessels, and risk-based designs.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Fuxing Li ◽  
Hao Liu ◽  
Menglei Li ◽  
Jun Guo ◽  
Xinjian Lu ◽  
...  

Inertia force is an important factor for operation stability and stamping precision of high-speed punch; adjusting drive torque of high-speed punch can realize effective control of inertia force. In this paper, a kind of 600 KN multilink high-speed punch inertia force balancing mechanism was designed. The calculation model of ideal inertia force was proposed based on conservation of energy and numerical analysis method. In addition, the calculation model of ideal driving torque were analyzed, simplified, and corrected by using numerical calculation and simulation methods, which solved the problem of controlling inertia force from the perspective of driving torque and realized the stability strategy planning of high-speed multilink punch press. Finally, the proposed ideal driving torque calculation model was simulated and verified by ADAMAS and bottom-dead-point accuracy test was carried out.


2015 ◽  
Author(s):  
Rodrigo Perez ◽  
Verónica Alonso

Many tools handle with the calculation of compartment definition, hydrostatics, intact and damage stability and power prediction, but these calculations are separated from the rest of ship CAD/CAM tools. Ship designers need to work closely with the shipyards, in a complex and distributed environment making necessary to have suitable tools at early design stages to ensure profitable projects. Naval architecture is handled in FORAN with a revolutionary approach, where integration and advanced features are the relevant characteristics in a single and complete set of applications that are used in conjunction to other disciplines, from concept design to operation. This new approach groups the former modules for naval architecture available in FORAN from many years, is intuitive and user-friendly. The information is stored in a database instead of a wide set of files. As regards this feature, there are two different alternatives depending on the scope of the project. If the ship designer wants to calculate only naval architecture calculations, the solutions is based on a SQLITE database suitable for a standalone application. This approach benefits a ship design office, in the study of different design alternatives very quickly but having a complete control of them. The other option is integrating the Naval Architecture with the rest of FORAN design disciplines, in a single database based in Oracle. In this case, the great benefit comes from the single truth of data from concept design to operation, which ensures dramatically the reduction of errors and re-work. After the definition of compartments in 3D, by using a very fast application, the module guides the user through the naval architecture calculations with a tree of elements very intuitive, with powerful key algorithms and with a solid representation of spaces. The definition of the necessary entities to make any kind of calculation is very fast. For the intact stability a set of standard stability criteria is provided. It is based in a quick definition of loading conditions, initial situations, flooding conditions and compartment subdivisions. And for the evaluation of the damage stability a set of standard stability criteria are also provided, following deterministic and probabilistic approaches. With these tools any naval architect is able to make very fast all the necessary studies to assure the stability regulations are complied with.


2021 ◽  
pp. 1-17
Author(s):  
Yibo Hu ◽  
Yanding Wei ◽  
Mengnan Liu

Abstract In order to reinforce the operation stability and obstacle capability of a spherical robot, this paper presents a spherical robot with high-speed rotating flywheel, the mechanical structure of which is mainly composed of a spherical shell, a double pendulum on both sides and two high-speed flywheels. The robot has three excitation modes: level running, self-stability operating and obstacle surmounting. The dynamic characteristics of the pendulum, flywheel and brake of the robot are discussed through the establishment of kinematic and dynamic model of the spherical robot and the influence of parameters like weight, flywheel speed and flywheel position on its dynamic characteristics and robot performance is optimized and analyzed in detail. The research results indicate that the two flywheels located in the center of the sphere apart can bring the maximum stability gain to the sphere. Finally, the simulation and experiment of the stability gain brought by the high-speed flywheel to the sphere verify that the operation stability of the sphere is effectively improved after using the flywheel, and the robot that stops the flywheel through a brake fixed on the pendulum has better obstacle surmounting performance.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.


Author(s):  
Nikolai Petrov ◽  
Nikolai Petrov ◽  
Inna Nikonorova ◽  
Inna Nikonorova ◽  
Vladimir Mashin ◽  
...  

High-speed railway "Moscow-Kazan" by the draft crosses the Volga (Kuibyshev reservoir) in Chuvashia region 500 m below the village of New Kushnikovo. The crossing plot is a right-bank landslide slope with a stepped surface. Its height is 80 m; the slope steepness -15-16o. The authors should assess the risk of landslides and recommend anti-landslide measures to ensure the safety of the future bridge. For this landslide factors have been analyzed, slope stability assessment has been performed and recommendations have been suggested. The role of the following factors have been analyzed: 1) hydrologic - erosion and abrasion reservoir and runoff role; 2) lithologyc (the presence of Urzhum and Northern Dvina horizons of plastically deformable rocks, displacement areas); 3) hydrogeological (the role of perched, ground and interstratal water); 4) geomorphological (presence of the elemental composition of sliding systems and their structure in the relief); 5) exogeodynamic (cycles and stages of landslide systems development, mechanisms and relationship between landslide tiers of different generations and blocks contained in tiers). As a result 6-7 computational models at each of the three engineering-geological sections were made. The stability was evaluated by the method “of the leaning slope”. It is proved that the slope is in a very stable state and requires the following measures: 1) unloading (truncation) of active heads blocks of landslide tiers) and the edge of the plateau, 2) regulation of the surface and groundwater flow, 3) concrete dam, if necessary.


2019 ◽  
Vol 12 (4) ◽  
pp. 339-349
Author(s):  
Junguo Wang ◽  
Daoping Gong ◽  
Rui Sun ◽  
Yongxiang Zhao

Background: With the rapid development of the high-speed railway, the dynamic performance such as running stability and safety of the high-speed train is increasingly important. This paper focuses on the dynamic performance of high-speed Electric Multiple Unit (EMU), especially the dynamic characteristics of the bogie frame and car body. Various patents have been discussed in this article. Objective: To develop the Multi-Body System (MBS) model of EMU, verify whether the dynamic performance meets the actual operation requirements, and provide some useful information for dynamics and structural design of the proposed EMU. Methods: According to the technical characteristics of a typical EMU, a MBS model is established via SIMPACK, and the measured data of China high-speed railway is taken as the excitation of track random irregularity. To test the dynamic performance of the EMU, including the stability and safety, some evaluation indexes such as wheel-axle lateral forces, wheel-axle lateral vertical forces, derailment coefficients and wheel unloading rates are also calculated and analyzed in detail. Results: The MBS model of EMU has better dynamic performance especially curving performance, and some evaluation indexes of the stability and safety have also reached China’s high-speed railway standards. Conclusion: The effectiveness of the proposed MBS model is verified, and the dynamic performance of the MBS model can meet the design requirements of high-speed EMU.


Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2301
Author(s):  
Man Zhang ◽  
Bin Liang ◽  
Hongjun He ◽  
Changjian Ji ◽  
Tingting Cui ◽  
...  

Appropriate pretreatment of proteins and addition of xanthan gum (XG) has the potential to improve the stability of oil-in-water (O/W) emulsions. However, the factors that regulate the enhancement and the mechanism are still not clear, which restricts the realization of improving the emulsion stability by directional design of its structure. Therefore, the effects of whey protein micro-gel particles (WPMPs) and WPMPs-XG complexes on the stability of O/W emulsion were investigated in this article to provide theoretical support. WPMPs with different structures were prepared by pretreatment (controlled high-speed shear treatment of heat-set WPC gels) at pH 3.5–8.5. The impact of initial WPC structure and XG addition on Turbiscan Indexes, mean droplet size and the peroxide values of O/W emulsions was investigated. The results indicate that WPMPs and XG can respectively inhibit droplet coalescence and gravitational separation to improve the physical stability of WPC-stabilized O/W emulsions. The pretreatment significantly enhanced the oxidative stability of WPC-stabilized O/W emulsions. The addition of XG did not necessarily enhance the oxidative stability of O/W emulsions. Whether the oxidative stability of the O/W emulsion with XG is increased or decreased depends on the interface structure of the protein-XG complex. This study has significant implications for the development of novel structures containing lipid phases that are susceptible to oxidation.


Author(s):  
K. Bobzin ◽  
M. Öte ◽  
M. A. Knoch ◽  
I. Alkhasli ◽  
H. Heinemann

AbstractIn plasma spraying, instabilities and fluctuations of the plasma jet have a significant influence on the particle in-flight temperatures and velocities, thus affecting the coating properties. This work introduces a new method to analyze the stability of plasma jets using high-speed videography. An approach is presented, which digitally examines the images to determine the size of the plasma jet core. By correlating this jet size with the acquisition time, a time-dependent signal of the plasma jet size is generated. In order to evaluate the stability of the plasma jet, this signal is analyzed by calculating its coefficient of variation cv. The method is validated by measuring the known difference in stability between a single-cathode and a cascaded multi-cathode plasma generator. For this purpose, a design of experiment, covering a variety of parameters, is conducted. To identify the cause of the plasma jet fluctuations, the frequency spectra are obtained and subsequently interpreted by means of the fast Fourier transformation. To quantify the significance of the fluctuations on the particle in-flight properties, a new single numerical parameter is introduced. This parameter is based on the fraction of the time-dependent signal of the plasma jet in the relevant frequency range.


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