Pontoon Structure Research Articles

Structure Analysis of Hybrid Marine Renewable Energy Platform

Abstract The Pilot Project Energy Laut Hybrid for coastal communities utilises a hybrid-based tripod pontoon structure. Hydrodynamic analysis was conducted using Computational Fluid Dynamic (CFD) simulations and Detail Engineering Design (DED) testing at the Hydrodynamics Laboratory of Indonesia (LHI). This research aims to conduct a structural analysis of the tripod pontoon frame, including redesigning and comparing the strength between the existing and modified designs. An analysis using the software SACS V15.1 was employed to obtain unity check values and stress distribution. The analysis revealed that the unity check values for the existing model, with airy wave01, airy wave02, stokes wave01, and stokes wave02, were 0.508, 0.498, 0.509, and 0.5, respectively. In contrast, the unity check values for the modified model, with airy wave01, airy wave02, stokes wave01 and stokes wave02, were 0.827, 0.81, 0.827, and 0.813, respectively, indicating a 63% increase in unity check for the modified model. The largest shear stress was observed on member A5-1-A5-2 in both models, which still complies with the API RP 2A-WSD standard. Additionally, the modified model was 21% lighter than the existing model, with Z shear stress increasing by 63% for both airy and stokes wave types.

Improvement of the calculation of ice crossings

Background: In winter, ice crossings open in the north of the Far Eastern region. In most cases, they are organized due to the lack of capital bridges. Ice crossings are used to deliver goods and passengers to remote settlements where the road network is poorly developed and the navigation period is limited, because to get to settlements it is necessary to cross reservoirs. Ice crossings remain the only way to connect such settlements with cities with a large population. The most reliable way to increase the load-bearing capacity is to freeze the floating bridge of the articulated circuit into the ice cover. The advantage of such crossings is low sensitivity to climatic conditions and the nature of the water flow, small rolls and sediment. Currently, these crossings are used at cross-border crossings of the Far East, but there are no calculation methods.
 Aim: Development of a methodology that would improve the calculation of ice crossings, taking into account the reinforcement in the form of metal pontoon structures consisting of articulated ferries on two supports.
 Materials and Methods: The article provides a calculation model. Design scheme: a metal structure frozen in ice lying on water is a rigid stamp on a plate lying on the elastic base of the crossing. To confirm the accepted calculation model, an experiment of a real crossing in the form of static tests was carried out.
 Results: The article presents the results of determining the crossing deflections according to the accepted calculation model and after the experiment. The carrying capacity of the reinforced ferry was also calculated by months.
 Conclusion: This study will help to carry out calculations of combined crossings for a significant increase in load-bearing capacity.

Effectiveness of Sacrificial Shielding for Blast Mitigation of Steel Floating Pontoons

Floating pontoons have played a supreme and indispensable role in crises and disasters for both civil and military purposes. Floating bridges and ferries are exposed to blast loadings in the case of wars or terrorist attacks. The protection effectiveness of sacrificial cladding subjected to a blast was numerically investigated. In this study, a steel ferry has been simulated and exposed to side explosions with different explosive charges at certain stand-off distances, according to military standards from NATO and American standard TM5. In this simulation, nonlinear three-dimensional hydro-code numerical simulation ANSYS autodyn-3d has been used. The results reported that the ferry could withstand a charge of 5 kg TNT at a stand-off distance of 1 m without failure. The main objective of this research is to achieve a design that would increase the capacity against the blast loading with minimal plastic deformation in the absence of any failure in the ferry. Therefore, an innovative mitigation system has been proposed to dissipate the blast energy of the explosion based on the scientific theory of impedance using sacrificial cladding. The new mitigation system used a specific structural system in order to install the existing pontoon structure without any distraction. The response, elastic deformations, plastic deformations and plastic failure of the ferry were illustrated in this paper. Furthermore, the results revealed that the proposed mitigation system could mitigate more than 50% of the blast waves. The new design revealed promising results, which makes it suitable for mitigating blast waves. Finally, the results were provided with a reference for the preliminary design and application of sacrificial cladding for structural protection against blast waves.

Designing Smart Floating Village In Belawan With Ecological Architecture Approach


 Rising sea levels are essential issues due to global warming increasing every year. This leads to the potential for the amount of land to be reduced. One of the areas in Medan that is directly adjacent to the water is Belawan Subdistrict. Based on the data observation of water level in the Belawan sub-district, there is a significant level change every year. Some areas in the coastal area of Belawan have the possibility of drowning. To overcome this, Smart Floating Village is designed as a floating settlement in the future. The method used to solve this design problem is through observation, literature studies, and precedent studies of similar projects that have been built. The analysis and study results obtained a large pontoon structure (VLFS) as the module's base used for floating settlements. Settlements based on large pontoon structure modules can have various activities such as housing and other community needs facilities. The Smart Village concept is also applied to this design to eliminate the perception of the slum environment in coastal residential areas. To connect the idea of a smart village and floating settlements, an ecological architecture approach is needed to maintain a balance between humans and the environment. This research is expected to be a further discussion study for further research on floating settlements that apply the innovative village concept and can be helpful in architectural science regarding case studies and similar approaches.

RESEARCH ON DAMAGE CHARACTERISTICS AND PROTECTIVE STRUCTURE DESIGN OF STEEL PONTOONS UNDER NEAR-FIELD EXPLOSION LOAD

The focus of this paper is to investigate the damage characteristics and protective structure design of pontoons as an important barrier for the protection of ports. Two types of protective measures of pontoons are investigated：filling tanks with water and installing springs in tanks. In this paper, the damage characteristics of two types of pontoon side structures under the action of near-field explosion loads are simulated by using LS-DYNA explicit dynamic analysis software and the ALE algorithm. According to the numerical experiment results for filling different volumes of water in the side tanks, the volume of water for the minimum deformation of the shell plate is 100%, and for the first longitudinal bulkhead, it is 30-40%. Moreover, by applying weights to their deformations based on the actual explosion-proof performance requirements of the shell plate and the first longitudinal bulkhead, the pontoon side structure with the best explosion-proof performance can be obtained. The plastic deformation of the pontoon structure equipped with different types of springs is an order of magnitude smaller than that of the ordinary structure and of the pontoon structure filled with a water medium in the positive tanks. The explosive shock wave energy absorbed by the pontoon is effectively reduced by the addition of water or springs to the protective tanks. The minimum energy absorbed by the pontoon structure with water added in the protective tanks is 18.31% of the energy absorbed by the ordinary structure, and the corresponding volume ratio of water added in the protective tanks is 100%. The pontoon structure with springs in the side protection tanks absorbs only 7.2% of the energy absorbed by the ordinary structure. Both new side protection structures have demonstrated excellent explosion-proof performance.

Regulation of Telescopic Water Intake Operations

Abstract Telescopic water intake structures play an important role in a water management system. The article is devoted to the improvement of telescopic water intake structures and the development of a solution for regulating their operation. Different types of water intakes are analyzed, and their shortcomings are identified. The structures of known telescopic water intakes are reviewed, and their operating principles are analyzed. It has been determined that the design of existing telescopic water intake structures lacks a device for stopping the operation of the intake of water. A structural solution for stopping and regulating the operation of a telescopic water intake is proposed. The construction of an additional ballast pontoon to be welded to the first section of the telescopic pipeline is proposed in order to regulate and stop the operation of the water intake. A methodology for calculating and designing an additional ballast pontoon for a telescopic water intake has been developed, and a specific example for its implementation has been provided. Based on the results of the research, the main parameters of the additional ballast pontoon structure have been established, and the methodology for its calculations has been developed.

Numerical investigation of the interception performance of HDPE pontoon-type port safety barrier system under boat attacking

In recent years, the risk of damage or failure of berthed ship has increased rapidly due to increase of accidental or deliberate ship/boat collision events. Therefore, suitable defense technology is necessary to minimize the casualty and economic loss caused by overwater collisions. This study uses the method of numerical simulation to evaluate the effect of HDPE pontoon port security barrier system under ship attack through the additional water mass method. Numerical models of HDPE pontoon and GFRP boat are developed and validated. The validated FE models are extended to full scale. Both pontoon and boat deformations are considered during the impact simulations as observed in practical situation. The dynamic impact analysis results show that the HDPE pontoon-type port safety barrier can provide enhanced impact resistance capacity of strengthened structural members by reducing lateral displacement about 40% compared to unreinforced pontoon. A comprehensive parametric study is conducted by varying the boat speed, boat mass, boat stiffness and boat lift angle to observe the effects of these parameters on the structural responses of pontoon structure. HDPE and pontoon-type structure are found to be promising defense technology to control global failure subjected to boat attacking.

Theoretical analysis of nonlinear fluid–structure interaction between large-scale polymer offshore floating photovoltaics and waves

The present research analyzes the nonlinear fluid–structure interaction (FSI) of free surface waves with large-scale polymer offshore floating photovoltaics (LPOFPV). The floating structure is modeled as a nonlinear Euler Bernoulli–von Kármán (EBVK) beam coupling with water beneath. The EBVK theory takes the in-plane force into consideration to account for the moderately large deflection slopes in LPOFPV. A multi-time-scale perturbation method leads to hierarchic partial differential equations by introducing the wave steepness squared as the perturbation. The analytical solution of the proposed nonlinear FSI model is obtained up to the second order. Pontoon structures and LPOFPV are studied and compared. The asymptotic solution provides the expressions of the propagating wave through the coupled system and its frequency–amplitude dispersion relation in a closed-form. A property of the solution is that the progressive plane wave through the coupled system remains linear for small dimensionless amplitudes, and features a second order correction for moderately large dimensionless amplitudes. Furthermore, it is also theoretically proven that no resonance occurs in the considered infinite problem. The proposed approach can be extended to the nonlinear coupling between a EBVK beam and Stokes waves.

Finite element - Multi-domain boundary element method for hydroelastic analysis of large floating pontoons with perforated plates

This paper presents a Finite Element-Multi-Domain Boundary Element (FE-MDBE) method for the hydroelastic analysis of large floating pontoon structures with perforated plates. The structure is modelled by the shell theory while the fluid motion is modelled by using the linear wave theory. When fluid flows through the perforated plates, it is assumed that the velocity is unchanged but the fluid pressure drops by an amount that is determined by an empirical relationship involving the fluid velocity and the porosity of the perforated plate. The equations governing the fluid-structure interaction are solved by using the Finite Element Method (FEM) and Multi-Domain Boundary Element Method (MDBEM). In the MDBEM, the fluid domain is imaginarily decomposed into interior and exterior domains so as to avoid the singularity that arises when using the conventional BEM for solving hydroelastic problems involving thin submerged structures. The proposed FE-MDBE method is verified by comparing its results with experimental results obtained for a flexible platform and a fixed cylinder with perforated sidewall. The verified method is used for the hydrodynamic and hydroelastic analyses of floating breakwaters and large floating platforms with vertical perforated plates at their fore and/or aft.

Analysis and Design of Steel a Floating Pontoon Jetty for Use in the Coastal Waters of Nigeria

Floating pontoons are semi-permanently moored structures on a water body to provide boarding access to commuters. The decision to develop such structures was informed by the need to provide berthing access to river crafts that operate on the coastal waters of Bayelsa State, Nigeria. In this project, a floating pontoon, a gangway, and other supporting structures like scantlings and spud pillars, were designed to meet the needs and environmental requirements of the area. Standards consulted are the DNV Rules for the classification of ships; DNV Rules for the classification of Floating Docks; ABS Rules for Building and Classing Steel Barges; and other relevant Nigeria and Imo standards. The pontoon designed has dimensions: 13 x 12 x 4.8 m; gross tonnage of 15 tonnes; 2nos. of dry tanks of capacity 17.2 m³ and 6nos. of manholes of 450 x 550 mm. The strength of materials analysis was limited to the floating pontoon for limitations of space for this paper. The pontoon and scantling design has been done based on the worst condition of design pressure which is for the maximum submersion draft. Normal grade steel of yield strength 235 MPa is chosen for all members except the pontoon girders, frames and pillars. This is to reduce the material scantlings and to ensure higher strength with lesser scantlings. Longitudinal framing is adopted in the pontoons as the pontoon structure needs more strength in the longitudinal direction.

Analysis and Design of Steel a Floating Pontoon Jetty for Use in the Coastal Waters of Nigeria

Floating pontoons are semi-permanently moored structures on a water body to provide boarding access to commuters. The decision to develop such structures was informed by the need to provide berthing access to river crafts that operate on the coastal waters of Bayelsa State, Nigeria. In this project, a floating pontoon, a gangway, and other supporting structures like scantlings and spud pillars, were designed to meet the needs and environmental requirements of the area. Standards consulted are the DNV Rules for the classification of ships; DNV Rules for the classification of Floating Docks; ABS Rules for Building and Classing Steel Barges; and other relevant Nigeria and Imo standards. The pontoon designed has dimensions: 13 x 12 x 4.8 m; gross tonnage of 15 tonnes; 2nos. of dry tanks of capacity 17.2 m³ and 6nos. of manholes of 450 x 550 mm. The strength of materials analysis was limited to the floating pontoon for limitations of space for this paper. The pontoon and scantling design has been done based on the worst condition of design pressure which is for the maximum submersion draft. Normal grade steel of yield strength 235 MPa is chosen for all members except the pontoon girders, frames and pillars. This is to reduce the material scantlings and to ensure higher strength with lesser scantlings. Longitudinal framing is adopted in the pontoons as the pontoon structure needs more strength in the longitudinal direction.

The Application Modular Floating Pontoon to Support Floods Disaster Evacuation System in Heavy Populated Residential Area

During floods disaster in the heavy populated residential area, the lack of existing life saving appliances system such as rubber boat and wooden boat were not able to evacuate the disaster victims spontaneously in mass. The condition might be explained since the rubber boat and wooden boat have limited occupant capacity. Based on the conditions, the main objectives of the research are focused on the evaluation of the application of modular floating pontoon as multipurpose floating equipment to support floods disaster evacuation process. The investigation of the modular floating pontoon performance such as hydrostatics characteristics, the equilibrium condition and the intact stability was studied using strip theory and Krylov’s method. Furthermore, the strength analysis of the modular floating pontoon structure was calculated using finite element method. The results show that the modular floating pontoon is reliable to support the evacuation process.

Hydrodynamic Study of a Fixed Pontoon Structure under Wave Loads with Different Reynolds Numbers

As a breakwater, a suspended fixed pontoon is expected to receive energy of the wave and to reduce the wave height at downstream as much as possible. However, in other applications like floating bridges, the structure is expected to allow the wave to pass with the lowest possible energy absorption. In the present study, a numerical investigation has been conducted to identify the effective types of floating pontoon with different rectangular and circular cross sections under regular waves at different Reynolds numbers. Volume of fluid scheme and finite volume methods have been applied for tracking the free surface and discretization of the governing equations, respectively. To implement these numerical schemes, a computer code was developed and validated, which computes the lift and drag as well as the transmission coefficient for each of the moored fixed structures.

A review of floating photovoltaic installations: 2007–2013

AbstractThe paper gives a review of the various projects that have been realised in throughout the years. These have all been in enclosed water bodies such as reservoirs, ponds and small lakes. The main motivation for the floating photovoltaic (PV) panels was the land premium, especially for agricultural sites were the land was more valuable for growth of the crops (in these cases, grapes because the sites were wineries). The PV panels of the existing projects are mounted on a rigid pontoon structure and vary between horizontal and tilted installations. Future concepts proposed for marine and large lacusterine sites are envisaged to incorporate laminated thin film PV, which would allow the structure to be flexible and able to yield with the oncoming waves, and submergible arrays, which would be submerged in harsh weather conditions. Interest and research has been developing in this niche field throughout the years and has currently reached the megawatt scale with even bigger plans for the future. Copyright © 2014 John Wiley & Sons, Ltd.

Dynamic behaviour of square and triangular offshore tension leg platforms under regular wave loads

Among compliant platforms, the tension leg platform (TLP) is a hybrid structure. With respect to the horizontal degrees of freedom, it is compliant and behaves like to a floating structure, whereas with respect to the vertical degrees of freedom, it is stiff and resembles a fixed structure and is not allowed to float freely. The greatest potential for reducing costs of a TLP in the short term is to go through previously applied design approaches, to simplify the design and reduce the conservatism that so far has been incorporated in the TLP design to accommodate for the unproven nature of this type of platform. Dynamic analysis of a triangular model TLP to regular waves is presented, considering the coupling between surge, sway, heave, roll, pitch and yaw degrees of freedom. The analysis considers various nonlinearities produced due to change in the tether tension and nonlinear hydrodynamic drag force. The wave forces on the elements of the pontoon structure are calculated using Airy's wave theory and Morison's equation, ignoring the diffraction effects. The nonlinear equation of motion is solved in the time domain using Newmark's beta integration scheme. Numerical studies are conducted to compare the coupled response of a triangular TLP with that of a square TLP and the effects of different parameters that influence the response are then investigated.

Nonlinear coupled response of offshore tension leg platforms to regular wave forces

Among the compliant platforms, the tension leg platform (TLP) is a vertically moored structure with excess buoyancy. The TLP is designed to behave in the same way as any other moored structure in horizontal plane, at the same time inheriting the stiffness of a fixed platform in the vertical plane. Dynamic response analysis of a TLP to deterministic first order wave forces is presented, considering coupling between the degrees-of-freedom surge, sway, heave, roll, pitch and yaw. The analysis considers nonlinearities produced due to changes in cable tension and due to nonlinear hydrodynamic drag forces. The wave forces on the elements of the pontoon structure are calculated using Airy's wave theory and Morison's equation ignoring diffraction effects. The nonlinear equation of motion is solved in the time domain by Newmark's beta integration scheme. The effects of different parameters that influence the response of the TLP are then investigated.