Due to the escalating demand for liquefied natural gas (LNG) as a low-emission and environmentally friendly energy source, ISO tank containers have emerged as an innovative solution to facilitate efficient and cost-effective mass transportation. The 40 ft ISO tank container, which encompasses a pressure vessel structure, is a versatile intermodal unit that seamlessly integrates into sea and land transportation networks. The main objective of this study is to present a comprehensive analysis for assessing the various frame design scenarios of the 40 ft ISO tank container for mini LNG carrier operation. The assessment is conducted under the provisions outlined in ASME Section VIII Division I code, which governs the design standards for boilers and pressure vessels. The finite-element analysis (FEA) scrutinizes three different structural design alternatives: frame thickness, the addition of support plates, and the addition of saddle supports, which are subjected to various loading conditions: stacking, lifting, and racking load tests. The analysis offers a comparative assessment of the safety level provided by the ASME design guidance in contrast to the FEA judgments based on ISO standards. It can be found that stacking and longitudinal load tests are more critical operational load scenarios. Increasing the frame thickness of the LNG ISO tank is more practical in increasing structural weight savings than adding more saddle supports and support plates.

LNG ISO tank containers are a solution for bulk liquefied natural gas (LNG) delivery to the outer islands of Indonesia that are not connected to the gas pipeline network. The design of an ISO tank frame must consider two critical parameters, strength/rigidity and weight saving, which affect the operational performance of the distribution process. The current investigation aims to numerically optimize the design of the structural frame of a 40 ft LNG ISO tank for a mini LNG carrier operation using a topology optimization framework. Two design solutions are used in the topology optimization framework: reducing the strain energy and mass retained. Mass retained was selected as the objective function to be minimized, which was assumed to be 60–80%. The proposed frame design is tested using three operational loading scenarios, including racking, lifting, and stacking tests based on the ISO 1496 standard. The convergence mesh tests were initially evaluated to obtain the appropriate mesh density in the finite element analysis (FEA). The simulation findings show that the topology optimization method of the frame design resulted in an improved design, with an increase in the strength-to-weight saving ratio. A promising result from the optimization scenario demonstrates weight savings of about 18.4–37.3%, with experienced stress below the limit criteria. It is found that decreasing mass retained causes a significant stress increase in the structural frame and ISO corner castings, especially in the stacking load. The critical recommendation in the frame design of the LNG ISO tank can be improved by eliminating the saddle support and bottom frame and increasing the thickness of the vertical frame.

Effective insulation is critical for traditional fishing boats because it helps to maintain the quality of the fish catch. Inadequate insulation can lead to significant economic losses for fishermen, as they may have to discard or sell the fish at a lower price. This study aimed to compare the thermal conductivity properties of three different insulation materials: Petung bamboo, polystyrene foam, and polyurethane foam. The experiment involved testing the density of the materials and conducting thermal conductivity tests. The results indicated that polyurethane foam is the best material for insulation because it has the lowest thermal conductivity value compared to laminated bamboo and polystyrene foam. The addition of more isocyanate mass fraction to the polyurethane foam material can increase its density and strength. This is because increasing the isocyanate concentration increases the cross-linking density of the foam, making it more durable and resilient. Moreover, higher density polyurethane foams exhibit lower heat conductivity, indicating better insulation qualities. This study highlights the importance of effective insulation to maintain the quality of the fish catch. The findings suggest that polyurethane foam, particularly with increased isocyanate concentration, is the most suitable material for insulation due to its superior insulation qualities.

This study investigates the crucial role of surface roughness caused by biofouling in contributing to increased drag in fast planing vessels. Through rigorous computational fluid dynamics (CFD) simulations using a full-scale reference hull, the impact of surface roughness on planing hull performance is examined. The results show that heavy slime roughness on the hull surface causes a significant increase in total resistance, ranging from 10% at low speeds to 80% at high speeds. Skin friction was identified as the most affected component of resistance, with additional changes in residual resistance. Although the change in residual resistance is relatively small, they give rise to dynamic phenomena such as variations in pressure distribution, wave elevation, and wave making formation. The study also explores the influence of surface roughness on dynamic lift forces, observing an increase in upward friction forces but ultimately concludes that overall hull performance was hampered due to the disproportionately higher increase in resistance caused by roughness (biofouling). Changes in dynamic trim, dynamic sinkage, and dynamic wetted surface area due to this roughness are also discussed.

As the largest maritime country in the world, Indonesia has abundant natural resources. Therefore, Indonesia has the potential to become the World Maritime Axis. However, it requires the development of a maritime process that includes aspects of infrastructure, politics, socio-culture, law, security and economy. Aspects that are vulnerable to threats are the national security and defines sectors that can harm the sovereignty of the Indonesian state. The losses experienced by the state result in damage to the marine ecosystem which affects national food security. The solution that can be applied is the use of unmanned vessels Unmanned Surface Vehicle (USV) as a patrol vessel to assist the implementation of defines and security guards in all border areas of Indonesia. This study was conducted to analyse the influence of the superstructure on the variation of monohull hull types that have the potential to improve the performance of patrol boats. To produce the best design, resistance and stability analysis is carried out based on hydrodynamicHydrodynamic criteria. The results of the research are expected to get the best prototype that can help security patrols and guard Indonesia's sea areas and can help to meet the Sustainable Development Goals.

The paper presents finite element (FE) simulations of an unstiffened plate specimen punched by a rigid indenter, to study their fracture behaviors and energy dissipation mechanisms. Load-displacement curves from the numerical results are presented for various indenter radii i.e., 35, 50, 65, 80, and 95 mm. Moreover, the outcomes of this investigation should have relevance to estimating grounding scenarios in which the bottom sustains local penetration. The numerical analysis includes the benchmarking study that is based on experimental data to ensure that the current result has satisfactory accuracy. It is concluded that the indenter radii play an important role in the crushing resistance of the plate, especially having a significant influence on the maximum force. Compared with the 35 mm cone radii, the maximum force measured in the tests increased by 110.97 % in the 95 mm indenter radius. Furthermore, the energy absorption produced by the 95 mm cone radius has a higher value at 32.23 kJ compared to 10.1 kJ, which was obtained from a 35 mm cone radius. Discussions on the effects of indenter velocities are also included in this study.

Steel is the primary shipbuilding material; however, it erodes quickly. Adequate protection requires hard, durable, and adhesive coatings. This study examines how aluminium-graphite pigment and heat treatment affect epoxy-coated SS400 steel plate corrosion, adhesion, and coating resilience. This study used a 1:1 and 3:1 pigment ratio with 100°C and 150°C heat treatment. The coating layer was 250 μm thick and comprised 80% epoxy and 20% aluminum-graphite. The maximum adhesion strength, 19.62 MPa, was achieved with an aluminium-graphite pigment ratio of 1:1 and 100°C heat treatment. The top coating resistance was 6.86 Joules under identical conditions. The lowest corrosion rate, 0.047 mmpy, was at a 3:1 aluminum-graphite ratio and 150°C heat treatment. This discovery has significant consequences for shipbuilding steel corrosion resistance.

A novel low-cost polyurethane (PU) elastomeric material reinforced with mat-form fiberglass for alternative ship material was developed. The hand lay-up technique was used to prepare samples with glass fiber contents of 0, 7, 9, 11, and 15% by weight. Several tests, including density, tensile, and hardness tests, have been conducted to investigate the effect of fiber content on the material properties of the developed materials. The test results found that only composites with 0% (PU) and 7% (PFg-7) fiberglass had met all Lloyd’s Register criteria. PFg-7 has a density of 1,098 kg/m3, a hardness of 66.15 shore-D, a tensile strength of 21.32 MPa, and an elongation at break of 47.06%, a higher hardness, elastic modulus, and yield strength than PU. PFg-15 achieved the highest density, hardness, tensile strength, elastic modulus, and yield strength, which were 1,228 kg/m3, 68.85 shore-D, 32.13, 2,176, and 30.89 MPa, respectively. The elastic modulus and yield strength of PFg-15 were 5.6 times and 3 times higher than those of PU but PFg-15 did not meet the elongation at break criteria. PFg-9, PFg-11, and PFg-15 showed brittle properties, as indicated by relatively high hardness, elastic modulus, and yield strength compared to the results from various references.

The high demand for steel and wood as the primary shipbuilding materials will increase market prices due to decreasing supplies each year. To address this issue, new alternative materials that are more environmentally friendly and inexpensive, such as natural fibers like bamboo and coconut fiber, must be explored. This study aimed to investigate how the directional arrangement (0° unidirectional and 90° unidirectional) of laminated Petung bamboo (Dendrocalamus asper) affects the compressive and flexural strength of ship construction. The compressive strength on the X, Y, and Z-axis was measured to determine the laminated beam’s strength ratio on each side. In contrast, the flexural strength was only observed on the Y and Z-axis due to testing equipment limitations. The results showed that the directional arrangement of laminated Petung bamboo with different test axes significantly impacted the compressive and flexural strength of laminated beams made of Petung bamboo and coconut coir fiber. Laminated Petung bamboo and coconut coir fiber with 0° unidirectional fiber had better compressive and flexural strength values than those with 90° unidirectional fiber. Based on the data testing, the combination of Petung bamboo and coconut coir fiber materials can be categorized into different strength classes. These findings have important implications for using laminated bamboo in shipbuilding applications. The use of laminated bamboo with a 0° lamina direction could be recommended for ship components that require high levels of strength than laminated bamboo with a 90° lamina direction.

Pitting corrosion is the most common, dangerous, and destructive corrosion type in marine and offshore structures. This type of corrosion can reduce the strength of the ship plate, so investigating it using several numerical grounding scenarios is needed to determine the significant degradation of the strength of the structural plate. In this study, a finite element study was used to evaluate the influence of pitting corrosion location on the strength of the bottom plate ship in grounding simulation. This study simulated 14 scenarios using different pitting positions on the bottom plate. Finite element using explicit dynamic simulation in LS Dyna software was employed to evaluate the strength of the bottom plate on the ship. The output parameters, such as reaction force and plate deformation, were assessed to compare the grounding simulation results. The simulation indicates that the location of pitting corrosion will affect stress concentration, crack initiation, reaction force, and penetrating position when the crack nucleates. The result shows the critical position of the pit, which is located near the stress concentration ring (nearly 100 mm from the center of the plates) in the plain plates.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Serliana Yulianti, Hanung Aulia Rahman Budi, Tuswan Tuswan, Eli Novita Sari, Abdi Ismail, Ahmad Ilham Ramadhani, Siti Duratun Nasiqiati Rosady; Conceptual design of a pelton turbine to supply the electricity need in Selur Village, Ponorogo. AIP Conference Proceedings 27 January 2023; 2540 (1): 100002. https://doi.org/10.1063/5.0125121 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

The SPS application in ship structure is an innovative breakthrough that provides an excellent strength-to-weight ratio. SPS application for new construction is crucial to ensure the proposed design has better static and dynamic behavior than conventional design. The study aims to evaluate the weight savings and dynamic characteristics of different proposed framing systems of 155 m barge due to the application of various SPS types in the deck, ship hull, and bottom structures. A total of three proposed construction systems: longitudinal, transverse, and mixed framing systems, are investigated under different plate configurations, material types, and scantling sizes. In addition, the free vibration analysis is used to evaluate the influence of damage occurrence on the structural characteristics. Several damage parameters, including damage size, location, shape, and depth, are investigated using ABAQUS software. The promising result of weight saving indicates SPS application results in about 9-13%. Moreover, the debonding assessment reveals that eigenvalue decreases with increasing debonding size, where the damaging eff ect in higher modes is more substantial. The stiff ness loss due to debonding causes a high local deformation in the debonded area. Moreover, interfacial debonding reduces eigenvalues signifi cantly, particularly in localized debonding shapes. It can be found that several damage parameters, including damage size, location, depth, and shape, influence the eigenvalue shifts.

Shear wall structure is one of the options as an appropriate lateral load-bearing system for new structures or as a means of retrofitting existing buildings. There are many types of shear walls, including steel plate shear walls (SPSWs). In enhancing its function, a thin SPSW is added with a stiffener. However, steel shear walls with stiffeners increase construction costs due to the time-consuming factor and the high cost of welding thin plates. Therefore, the infill shape was modified to increase the energy dissipation capacity of the SPSW. This study conducted simulations by varying the geometry, mesh, load factor, and materials used in SPSW. The specimen was modeled and tested using the ABAQUS application's finite element analysis. The simulation was done by ignoring welded joints, fish plates, and bolts. The result that was the output of the simulation was hysteresis behavior. In addition, the contours that occurred were also observed in this study. The H1 shape had the best hysteresis force-displacement graphics among the nine other geometric shapes. Ten mesh sizes were tested, starting from 25 mm and increasing by multiples of 10 up to 115 mm. The results showed significant differences, with a 33.3% increase at the 115 mm size, which was considered irrational. The load factor represented the applied load in each substep, and a load factor of 2 means the load was doubled compared to a load factor of 1. Seven materials were tested, and high carbon steel outperformed others as it can handle loads up to 1,000 kN, demonstrating excellent energy dissipation capabilities.

The shipping industry is the primary and most significant mode of international cargo transportation. The ship must comply with strict rules regarding reducing greenhouse gas (GHG) emissions as a dominant transportation mode. Liquified Natural Gas (LNG) is the primary alternative fuel option for several shipping companies. In essence, many studies recommend LNG as a transitional and alternative fuel because its emission characteristics are cleaner than other fossil fuels. Several previous investigations have been carried out to develop an action plan for integrating the use of LNG as a ship fuel. However, there have been few discussions on the estimation of GHG emission reduction and the economic efficiency of a representative LNG-fuelled ship. The recent progress on LNG-fuelled ships is systematically reviewed to summarize the pathways and highlight the core technological concepts, technical issues, current LNG-fuelled ship applications, and future outlooks regarding integrating LNG energy resources into ship power systems to measure GHG emission reductions and cost savings estimations. The report will discuss the current development in the maritime sector and the effects of the macroeconomic scale. The result reveals that future research on ship-based LNG energy systems will probably concentrate on integrating new energy source generating strategies with existing ship power systems to improve energy efficiency. Several potential research areas for future outlook were also discussed to anticipate future challenges.

A fast patrol boat is one of the ships intended to defend a region and rescue and search in the accident event so that the ship must have a high level of security and survivability performances. This study uses 9 design variations with various main dimensions and hull lengths to determine the effect of the different main dimensions on the hydrodynamic performances. Each criterion was affected to obtain results in hull design, durability, stability, seakeeping, floodable length, and motion sickness incidence (MSI). Simulations are carried out to determine the resistance, stability, ship response when exposed to external forces, passenger comfort, and ship safety level when a leak occurs. Resistance simulation uses a Froude number between 0 to 2.217. Stability simulation analyzes max GZ and angle of maximum GZ on seakeeping, deck wetness, and MSI simulations using 90°, 135°, and 180° wave incidence angles. The addition of bulkheads is carried out to determine the ship's response when it experiences a leak and prevents the ship's sinking when puddles enter the ship with five bulkheads per hull and three variations in distance. Design and simulation of various criteria using Maxsurf software. In the floodable length simulation, the hull added a bulkhead to determine the effect of leakage from several hull designs and watertight bulkhead spacing variations. Design 7 has the best average result compared to other designs from the simulation recapitulation results. It has a small resistance value, a large stability angle, a stable ship response when subjected to external forces, seasickness levels, and a small deck language. From the floodable length graph, it has a high flood limit that makes the ship survive and be safer than other designs. Design 7 refers to the ship Grandweld Shipyard Delivers 21M Discovery Class Vessel Fujairah Pilot.

The selection of a hull design with minimal drag is an important effort to reduce emission levels on ships. Two different hull shapes, U and V hulls, have unique properties that affect their drag production, which has been studied extensively in the past. This study aims to re-examine the differences between the two hull types by conducting a simple analysis of drag prediction results using empirical and numerical slender body methods. Both hull models in this study have the same size and volume. The results indicate that the U hull has a higher frictional resistance ( ) than the V hull due to its wider wetted surface area ( ). Additionally, the viscous pressure resistance ( ) and form factor coefficient ( ) of the U hull are also higher than those of the V hull. However, for Froude numbers (Fr) above 0.245, the U hull has lower wave resistance ( ) than the V hull, whereas for Fr below 0.245, the U hull has higher . Overall, the U hull produces a higher total resistance ( ) than the V hull at low speeds, but a lower at high speeds. Therefore, the choice of hull shape for minimizing a ship's resistance is influenced by the desired speed of service. If Fr is low, below 0.24, a V-shaped hull is more suitable. However, if Fr is higher than 0.24, a U-shaped hull is more appropriate.

The sandwich, as an advanced material, increases innovation in the field of ship construction. One of the applications is on the ramp door structure. The characteristics of sandwich material which are light and strong, are the main reasons for the application of this material. However, sandwich material also has drawbacks, one of which is debonding damage, where the bond between the face and core is released. This damage can affect the structure’s stiffness, which impacts reducing the strength of the structure on the ramp door. The effect of debonding is identified by performing numerical tests using finite element software. This test aims to identify the ramp door’s dynamic response due to the debonding damage’s influence. This research uses finite element software with an explicit dynamics method to determine the dynamic response of stress and displacement due to loading on the ramp door. The results of testing with finite element software show that an increase in the ratio of debonding damage causes the amplitude of the dynamic response to increase when subjected to transient loading.