• 자동차안전학회지
• /
• 제9권2호
• /
• pp.26-32
• /
• 2017

This paper presents the lateral stability criteria for integrated chassis control. To determine the intervention timing of chassis control system, the lateral stability criteria is needed. The proposed lateral stability criteria is based on velocity-yawrate gain domain to determine whether vehicle is stable. If the yawrate gain violates the proposed criteria, the stability of the vehicle is considered as unstable. Characteristic velocity and critical velocity are employed to distinguish lateral stability criteria. The inside of the two boundaries is stable and the outside is unstable. If yawrate gain of vehicle violates the lateral stability criteria, the chassis control begin to intervene. To validate the lateral stability criteria, both computer simulations and vehicle test are conducted with respect to circular turn scenario. The proposed lateral stability criteria makes it possible to reduce intervention of chassis control system.

• 해양환경안전학회지
• /
• 제4권2호
• /
• pp.53-62
• /
• 1998

International Maritime Organizatin(IMO) has been chosen some of agreements for regulating the international stability criteria of fishing vessels and recommended that each goverment adopts theirs into the domestic law. As a result, 77/93 Fishing Safety Agreement was ratified. Among the above agreement, contents of stability was not only applied to domestic law, but also strenghten considerably compared with existing stability criteria. And even if the calculation guide of stability with recommendations was regualted, Analysis of stability on domestic fishing vessels never have been used according to such a caculation method. Moreover, the caculation of stability criteria caused by strong wind, rolling effect and deck inflow was not considered in the existing basic design program. Therefore, the development of stability criteria program available for such a caculation has been of vital impotance. This research has developed a stability criteria program under 77/93 Fishing Safety Agreement. Also through development of stability criteria program, the stability performance of fishing vessel with 69ton stow-nesting was evaluated.

• 한국해양공학회지
• /
• 제33권6호
• /
• pp.518-525
• /
• 2019

Recently, the Sub-Committee on SDC (Ship Design and Construction) of IMO have discussed actively the technical issues associated with the second-generation intact stability criteria of ships. Generally, second generation intact stability criteria refer to vulnerability five modes ship stability which occurs when the ship navigating in rough seas. As waves passes the ship, dynamic roll motion phenomenon will affect ship stability that may lead to capsizing. Multi-tiered approach for second generation of intact stability criteria of IMO instruments covers apply for all ships. Each ship is checked for vulnerability to pure loss of stability, parametric roll, and broaching/surf-riding phenomena using L1(level 1) vulnerability criteria. If a possible vulnerability is detected, then the L2(level 2) criteria is used, followed by direct stability assessment, if necessary. In this study, we propose a new method to verify the criteria of the surf-riding/broaching mode of small ships. In case, L1 vulnerability criteria is not satisfied based on the relatively simple calculation using the Froude number, we presented the calculation code for the L2 criteria considering the hydrodynamics in waves to perform the more complicated calculation. Then the vulnerability criteria were reviewed based on the data for a given ship. The value of C, which is the probability of the vulnerability criteria for surf-riding/broaching, was calculated. The criteria value C is considered in new approach method using the Froude-Krylov force and the diffraction force. The result shows lower values when considering both the Froude-rylov force and the diffraction force than with only the Froude-Krylov force was considered. This difference means that when dynamic roll motion of ship, more exact wave force needs considered for second generation intact stability criteria This result will contribute to basic ship design process according to the IMO Second-Generation Intact Stability Criteria.

• 대한수학회지
• /
• 제37권5호
• /
• pp.657-664
• /
• 2000

A new concept of stability that includes Lyapunov and orbital stabilities and leads to concepts in between them is discussed in terms of a given topology of the function space. The criteria for such new concepts to hold are investigted employing suitably Lyapunov-like functions and the comparison principle.

• 선박안전
• /
• 통권22호
• /
• pp.19-33
• /
• 2007

According to amendments of ship safety act which comes into force from 4 Nov. 2007, the amended stability criteria should be applied to the small vessels of 12m or more in length. In this paper, the dimensions of domestic small vessels and the casualty reports of capsizing accidents are analyzed. And 58 ships are sampled, modeled for the investigation of the stability performance. Based on the regression analysis of the model ship's allowable metacentric-heights under several stability requirements, stability criteria for small fishing vessels and cargo ships are proposed.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 춘계 학술발표회
• /
• pp.1264-1270
• /
• 2010

In this study, the effects of slope inclination and rainfall on weathered soil slope stability were investigated for current cut soil slope design criteria. A series of slope stability analysis was performed on the slopes with the same height (5m), but different inclinations (1:0.8, 1:1, 1:1.2, 1:1.5, 1:2). Seepage analysis was also conducted to examine the rainfall effects directly and compare the combined seepage and slope stability analysis results with the slope stability analysis results for rainy season from the current cut soil slope design criteria. Typical properties for weathered soils were used in both the slope and seepage analysis. The analysis results showed that, for the slopes much steeper than the standard slopes, the factor of safety criteria were satisfied. Therefore, it appears that the slope designs by current cut soil slope design criteria lead to conservative results.

• 해양환경안전학회지
• /
• 제28권2호
• /
• pp.290-296
• /
• 2022

전 세계 해상 선박사고 건수는 감소하고 있지만, 국내 해상 사고 건수는 증가하고 있다. 이러한 이유에서 국내 선박의 해양 사고를 줄이기 위한 한 가지 방법으로 사고 건수가 가장 많은 어선과 낚시어선을 대상으로 하는 어선복원성기준에 관한 연구를 수행한다. 국제해사기구(IMO)와 국내 그리고 일본, 중국, 캐나다 해외 3개국의 어선복원성기준을 각각 조사하고, 상호 비교 분석한 결과외국의 기준들 대비 국내 기준이 가장 완화된 기준임을 알 수 있었다. 비교 분석 결과를 토대로 국내 어선복원성 기준을 보완하기 위한 어선복원성기준 개정(안)을 5가지 평가항목에 대해서 제안했다.

• 한국해양공학회지
• /
• 제34권2호
• /
• pp.55-65
• /
• 2020

A review of the 2nd generation of intact stability by the International Maritime Organization is performed. The main issues with the new stability criteria are reviewed. In particular, the physical background and related mathematical formulations of the pure loss of stability and parametric roll are summarized. Based on a literature review, benchmark calculation results for 17 different types of ships are discussed, and the final results are in excellent agreement with our physical expectations. Some relatively serious design problems are found in the application of the new stability criteria to sample ships built in Korea, and possible technical solutions are proposed, which have to be improved in the coming years.

• 대한조선학회논문집
• /
• 제44권3호
• /
• pp.285-295
• /
• 2007

In order to ensure safety of small vessels, the amended Ship Safety Act will come into force on 4th. Nov. 2007. This study is performed to suggest the stability criteria of fishing vessels and cargo ships of 12m in length and over but less than 24m in length which will be new object of amended Ship Safety Act. We have analyze the dimensions of domestic small vessels and the casualty reports of capsizing accidents. According to the analyzed result, 58 ships that are in the range of the dimension are modeled and the stability calculation has been carried out. The Stability for the 58 ships has been analyzed by comparing the result that applied the selected standard in the national standard to the stability calculation. Based on the regression analysis of the model ship's allowable transverse metacentric-heights under several stability requirements, stability criteria for small fishing vessels and cargo ships are proposed.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제13권1호
• /
• pp.545-553
• /
• 2021

International Maritime Organization (IMO) have recently discussed the technical problems related to the second-generation intact stability criteria of ships. The second-generation intact stability criteria refer to five modes of vulnerability when the ship sailing in the ocean. In this study, we described a method to verify the criteria of the surf-riding/broaching. In case that Lv1 (Level 1) vulnerability criteria is not satisfied based on the relatively simple calculation using the Froude number (Fn), we presented the calculation procedure for the Lv2 (Level 2) criteria considering the hydrodynamics in waves. The results were reviewed based on the data for given previous ships. In absence of ship-specific data, a similar Lv2 result was confirmed by comparing the result obtained by calculating the added mass with the case where the added mass was 10% of the ship mass. This result will contribute to basic ship design process according to the IMO draft regulation.