scholarly journals The Stability Analyze of KM. Rejeki Baru Kharisma of Tarakan – Tanjung Selor Route

Teknik ◽  
2021 ◽  
Vol 42 (1) ◽  
pp. 52-62
Author(s):  
Alamsyah Alamsyah ◽  
Zen Zulkarnaen ◽  
Suardi Suardi
Keyword(s):  
Stability Analysis ◽  
Stability Criteria ◽  
Load Case ◽  
Ship Stability ◽  
Intact Stability ◽  
Ship Capsize ◽  
The Stability ◽  
Stability Area ◽  
The Ideal

Ship stability that is not according to the IMO standard will make the ship capsize when operating. The purpose of this research is to determine the cause of the overturn in terms of the stability criteria of the ship. The method used is software  of simulation. Stability analysis is carried out with the load case that occurs in the field when an accident occurs and the ideal loadcase according to PM 104 2017 standards about’s the transportation of operation. The results showed is cargo of goods placed on the roof top (loadcase 1) based on the criteria of Intact Stability; area of the stability arm curve at heeling 0° ~ 30° = 0.9417 m.deg, area 0° ~ 40° = 1,0200 m.deg, 30° ~ 40° = 0.0783 m.deg, GZ value at heeling 30° = 0.029 m, angle of occurrence of maximum GZ = 21.8°, and the initial GMt value = 0.135 m, the results stated that all did not meet the Intact Stability code A.749 criteria, while in it was obtained cargo of goods placed in the hull (loadcase 2) based on Intact Stability; area of the stability arm curve at heeling 0° ~ 30° = 4.5338 m.deg, area 0° ~ 40° = 7.1643 m.deg, area 30° ~ 40° = 2.6305 m.deg, GZ value at heeling 30° = 0.265 m, angle of occurrence of maximum GZ = 34.5°, and the initial GMt value = 0.621 m, the results stated that all met the Intact Stability code A.749 criteria

scholarly journals Stability Study of Flat Hull Ship for Fishing Tourism

Teknomekanik ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 80-85
Author(s):  
Rahmat Azis Nabawi ◽  
Syahril Syahril ◽  
Salmat Salmat
Keyword(s):  
Flat Plate ◽  
Simulation Method ◽  
Stability Study ◽  
International Maritime Organization ◽  
Design Criteria ◽  
Stability Criteria ◽  
Load Case ◽  
Ship Stability ◽  
Minimum Standards ◽  
The Stability

The availability of boats is needed to develop fishing tourism. Most of the boats used so far generally use fishing boats made of woodcut in the forest, so this can damage the environment and cause natural disasters. Ships using a flat plate hull made of steel can be a substitute for wooden ships. This study aims to test the stability of a flat plate vessel designed for fishing boats. The ship stability test was carried out using a computer simulation method using Maxsurf Stability software. The ship stability criteria refer to the International Maritime Organization code A.749 (18), Ch 3-design criteria applicable to all ships. The ship stability analysis was carried out on two variations of the load case. The value of GZ at A h 300, A h 400 and A h 300 - A h 400 for load case 1 and 2 are greater than the minimum standards determined by IMO. The maximum GZ value at load case 1 occurs at an angle of 400 and at load case 2 at an angle of 60.90. The GM value in load case 1 is 0.609 meters and in load case 2 is 0.485 meters. Based on the results of the tests that have been carried out, it can be denied that the flatboat design model for fishing tourism meets the criteria set by the International Maritime Organization.

scholarly journals Risk Assessment Fishing Vessel Based for the Intact Ship Stability

2021 ◽  
Vol 934 (1) ◽  
pp. 012062
Author(s):  
B Santoso ◽  
R Romadoni ◽  
S Suzdayan ◽  
P Nasution
Keyword(s):  
Risk Assessment ◽  
Safety Assessment ◽  
International Maritime Organization ◽  
Stability Criteria ◽  
Load Case ◽  
Fishing Vessel ◽  
Ship Stability ◽  
Stability Curve ◽  
Ship Model ◽  
The Stability

Abstract Application of safety assessment and risk analysis using a risk-based approach for ship stability in ship operations at sea. However, there are currently no specific criteria and computational methods for risk assessment of ship stability. Based on the stability requirements for fishing activities at sea, the ship stability criteria will be explained in detail in this study. Calculation of stability used to obtain the GZ enforcement arm is carried out with the help of software for the shaking period using the International Maritime Organization (IMO) formula. Next, how to calculate parameters and determine certain coefficients for risk assessment of ship stability, and how to redraw the stability curve. Finally, proposed method is applied to ship model with comments and recommendations for monitoring to provide and overview. The study result indicate that the five loading conditions that occur on the ship have good stability by the criteria set by the International Maritime Organization (IMO). The value of GMt in each condition includes condition 1 and so on, 0.48; 0.48; 0.47; 0.46; 0.43. The results are presented in the form of F-N. Finally the sensitivity of the model is evaluated along with the assessment of associated uncertainties. The FN graph represents acceptable areas and unacceptable areas. Based on the results of data processing, the highest GM at GM Load-case 5 0.638 meters is in the Acceptable area. While Load-case 1 to Load-case 4 GM values sequentially Load-case 1: 0.487 meters; Load-case 2: 0.488 meters; Load-case 3: 0.47 meters; Load-case 4: 0.468 meters; is in an unacceptable area Unacceptable.

Stability of time-dependent rotational Couette flow Part 2. Stability analysis

1971 ◽  
Vol 48 (2) ◽  
pp. 365-384 ◽  
Author(s):  
C. F. Chen ◽  
R. P. Kirchner
Keyword(s):  
Growth Rate ◽  
Stability Analysis ◽  
Kinetic Energy ◽  
Initial Value Problem ◽  
Basic Flow ◽  
The Other ◽  
Time Dependent ◽  
Stability Criteria ◽  
Initial Value ◽  
The Stability

The stability of the flow induced by an impulsively started inner cylinder in a Couette flow apparatus is investigated by using a linear stability analysis. Two approaches are taken; one is the treatment as an initial-value problem in which the time evolution of the initially distributed small random perturbations of given wavelength is monitored by numerically integrating the unsteady perturbation equations. The other is the quasi-steady approach, in which the stability of the instantaneous velocity profile of the basic flow is analyzed. With the quasi-steady approach, two stability criteria are investigated; one is the standard zero perturbation growth rate definition of stability, and the other is the momentary stability criterion in which the evolution of the basic flow velocity field is partially taken into account. In the initial-value problem approach, the predicted critical wavelengths agree remarkably well with those found experimentally. The kinetic energy of the perturbations decreases initially, reaches a minimum, then grows exponentially. By comparing with the experimental results, it may be concluded that when the perturbation kinetic energy has grown a thousand-fold, the secondary flow pattern is clearly visible. The time of intrinsic instability (the time at which perturbations first tend to grow) is about ¼ of the time required for a thousandfold increase, when the instability disks are clearly observable. With the quasi-steady approach, the critical times for marginal stability are comparable to those found using the initial-value problem approach. The predicted critical wavelengths, however, are about 1½ to 2 times larger than those observed. Both of these points are in agreement with the findings of Mahler, Schechter & Wissler (1968) treating the stability of a fluid layer with time-dependent density gradients. The zero growth rate and the momentary stability criteria give approximately the same results.

Research on Surrounding Rock Stability by Ideal Point-Rough Set Efficacy Coefficient Method

2013 ◽  
Vol 353-356 ◽  
pp. 415-420 ◽  
Author(s):  
Guo Ren Lu ◽  
Le Wen Zhang ◽  
Dao Hong Qiu ◽  
Xiao Feng
Keyword(s):  
Stability Analysis ◽  
Rough Set ◽  
Ideal Point ◽  
Surrounding Rock ◽  
Ideal Solution ◽  
Rock Stability ◽  
The Stability ◽  
Efficacy Coefficient Method ◽  
Coefficient Method ◽  
The Ideal

The ideal point method is a kind of multiple-goal decision analysis method, the basic idea is to construct the ideal and anti-ideal solution of multi attribute problem, with degree that near ideal solution and away from the anti-ideal solution as the basis to judge each evaluation object. Based on the basic principle of ideal point method, and comprehensive consideration of the actual geological conditions of Qingdao metro, we selected rock compressive strength, integrity coefficient, structure surface behavior, groundwater and softening coefficient as the evaluation factors of surrounding rock stability, and used the rough set theory to determine the index weight. At last, established the evaluate model for the surrounding rock stability of metro based on the rough set efficacy coefficient method. The research show that the stability analysis results are consistent with the actual excavation, so using rough set efficacy coefficient method to analysis surrounding rock stability of Qingdao Metro is feasible, which provides a new idea for the stability analysis of surrounding rock.

Stability Criteria and Analysis of a Monocolumn Concept

2004 ◽  
Author(s):  
Felipe Cruz Rodrigues de Campos ◽  
Marcos Cueva ◽  
Kazuo Nishimoto ◽  
Ana Paula Dos Santos Costa
Keyword(s):  
Stability Analysis ◽  
Offshore Structures ◽  
Oil Fields ◽  
Stability Criteria ◽  
Offshore Drilling ◽  
Steel Catenary Risers ◽  
Special Concern ◽  
The Stability ◽  
Almost All ◽  
Classification Society

To be classified and approved by a classification society, all offshore structures shall be submitted and analyzed according to standard rules. The stability criteria are based on the IMO–MODU (International Maritime Organization–Mobile Offshore Drilling Units) Code which has reference to almost all types of floating units such as surface, column-stabilized and self elevating, but problems were found when dealing with monocolumn concept due to differences between this concept and those presented by the rules. The monocolumn studied is a floating production system (FPS) platform designed to handle steel catenary risers (SCR) in a depth of 1800 m in Brazilian oil fields. In this project, special concern was given to sea keeping behavior, constructability and security. This paper discusses the last item, focusing on subdivision and stability analysis. In order to overcome difficulties in finding the appropriate criteria, the work was developed using a special criteria, discussed with Det Norske Veritas (DNV) and PETROBRAS, which could be implanted in future classifications for this type of hull.

Influence of Systematic Hull Shape Variations on Ship Stability Performances in Waves

2020 ◽  
pp. 1-14
Author(s):  
Nicola Petacco ◽  
Giuliano Vernengo ◽  
Diego Villa ◽  
Antonio Coppedé ◽  
Paola Gualeni
Keyword(s):  
Second Generation ◽  
Design Space ◽  
Failure Modes ◽  
Free Form ◽  
Stability Criteria ◽  
Ship Stability ◽  
Parametric Roll ◽  
Modern Approach ◽  
Intact Stability ◽  
Geometric Variation

The sensitivity of ship stability performance in waves to geometric variation has been investigated by means of a simulation-based design framework. The study was devoted to assess the influence of hull geometry variations on some stability failure modes, namely, parametric roll (PR) and pure loss of stability (PLS). The application has been developed by using a representative model of a postpanamax container vessel. PR and PLS phenomena have been investigated by the application of second-generation intact stability criteria (SGISc). The initial multidimensional design space has been filled by 500 design configurations identified by means of a design of experiments approach. A method developed in-house, combining the subdivision surface and free-form deformation approaches, has been used to create the whole set of design alternatives. The generated design configurations have been assessed analyzing the results derived from application of the first- and the second-level SGIS vulnerability criteria for both the selected stability failure modes. To strengthen the correlation behaviors, the design space has then been further explored by using 10k design configurations exploiting the capabilities of a surrogate model-based approximation, relying on a Gaussian process formulation. The study has been focused on the correlations among the variables and the response functions, i.e., the outcomes of the SGIS vulnerability criteria. The significance, in terms of effects, of each geometry shape variable has been investigated. Results have been discussed in the light of the SGISc structure, to provide further insight into this innovative safety framework for a modern approach to intact stability. 1. Introduction In the last 10 years, the development of the so-called second-generation intact stability criteria (SGISc) has been one of the most engaging topics addressed by the Sub-Committee on Safety Design and Construction (SDC) of the International Maritime Organization (IMO).

The Direct Evaluation Method of Dead Ship Stability for Intact Ship

2019 ◽  
Vol 161 (A3) ◽  
Keyword(s):  
Second Generation ◽  
Evaluation Method ◽  
Stability Criteria ◽  
Ship Stability ◽  
Direct Evaluation ◽  
Intact Stability ◽  
Capsizing Probability ◽  
The Dead ◽  
The Difference ◽  
Effective Wave

The International Maritime Organization is currently establishing second generation intact stability criteria, the dead ship stability is considered one important criterion, so the development of its direct stability assessment regulation has become a topic undergoing close review. In this paper a peak-over-threshold (POT) method is proposed to evaluate the dead ship stability, which focuses on the statistical extrapolation that exceed the threshold, also the traditional Monte Carlo simulation is carried out to approve the method. On the basis of verification calculation of the sample ship CEHIPAR2792, the capsizing probability of a certain warship is also conducted. Moreover, the influence of initial stability height GM and effective wave slope coefficient on the capsizing probability is analysed. The results and the possible reason for the difference are examined. This study is expected to provide technical support for the second-generation stability criteria and establish the capsizing probability of damaged dead ship stability.

scholarly journals Stability Analysis of Pulse-Width-Modulated Feedback Systems with Time-Varying Delays

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zhong Zhang ◽  
Huahui Han ◽  
Qiling Zhao ◽  
Lixia Ye
Keyword(s):  
Stability Analysis ◽  
Stability Problem ◽  
Pulse Width ◽  
Time Varying ◽  
Stability Criteria ◽  
Feedback Systems ◽  
Stochastic Perturbations ◽  
Pulse Width Modulated ◽  
The Stability ◽  
Moment Exponential Stability

The stability problem of pulse-width-modulated feedback systems with time-varying delays and stochastic perturbations is studied. With the help of an improved functional construction method, we establish a new Lyapunov-Krasovskii functional and derive several stability criteria aboutpth moment exponential stability.

The mechanical properties of perfect crystals II. The stability and mode of fracture of highly stressed ideal crystals

1972 ◽  
Vol 330 (1582) ◽  
pp. 309-317 ◽  
Keyword(s):  
Sodium Chloride ◽  
Strain Curve ◽  
Lennard Jones Potential ◽  
Stability Criteria ◽  
Stress Strain Curve ◽  
Jones Potential ◽  
Lennard Jones ◽  
The Stability ◽  
Highly Strained ◽  
The Ideal

The Born stability criteria are applied to variously elastically deformed perfect crystals of argon, represented by a Lennard-Jones potential, and sodium chloride, represented by a Born-Mayer potential. It is shown that when highly strained in tension argon and sodium chloride crystals become unstable before the maximum in the ideal stress-strain curve is reached. The consequent reductions in our previous estimates of the ideal tensile strength (part I) are small (< 10 %) except for unconstrained tension of argon (20 %).

A unique application and point of truth for Naval Architecture Calculations

2015 ◽  
Author(s):  
Rodrigo Perez ◽  
Verónica Alonso
Keyword(s):  
Concept Design ◽  
Stability Criteria ◽  
Power Prediction ◽  
Naval Architecture ◽  
Complete Control ◽  
Intact Stability ◽  
Damage Stability ◽  
Cad Cam ◽  
The Stability ◽  
Definition Of

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.

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