Slamming Strength Assessment Analysis of Large Container Ship
0
Citation
5
Reference
10
Related Paper
Abstract:
The analysis of slamming effect has been mainly discussed about the local strength assessment and the global longitudinal strength assessment under slamming loads. The former is to forecast the local design pressure and access the local structural strength. To achieve the strength assessment of local structure of the ship bow, the slamming design pressure results of bow bottom and bow flare areas have been selected, so as to show the calculation results of relative velocity extreme values and design slamming pressure. And then according to the slamming loads and strength assessment, the direct strength assessments have been used to check key areas. The latter is to forecast the global vertical design moment and access the global longitudinal strength through three dimension finite model.Keywords:
Slamming
The analysis of slamming effect has been mainly discussed about the local strength assessment and the global longitudinal strength assessment under slamming loads. The former is to forecast the local design pressure and access the local structural strength. To achieve the strength assessment of local structure of the ship bow, the slamming design pressure results of bow bottom and bow flare areas have been selected, so as to show the calculation results of relative velocity extreme values and design slamming pressure. And then according to the slamming loads and strength assessment, the direct strength assessments have been used to check key areas. The latter is to forecast the global vertical design moment and access the global longitudinal strength through three dimension finite model.
Slamming
Cite
Citations (0)
Slamming loads on hull cross-sections are studied by a boundary element method, a similarity solution and an asymptotic solution. Pressure distributions on wedges with deadrise angles between 4o and 81o are presented. It is documented that the asymptotic solution is a reliable and practical method for small deadrise angles. The asymptotic method is generalized to wetdeck slamming. The wetted deck area as a function of time is found by solving an integral equation. The results show that the wave slope is important for the slamming load level. The method for wetdeck slamming is incorporated in a time-domain solution for wave induced motions and accelerations of high-speed catamarans. It is demonstrated that the slamming loads on the wetdeck can have an important influence on the vertical accelerations of a catamaran.
Slamming
Hydroelasticity
Cite
Citations (7)
Slamming
Smoothed Particle Hydrodynamics
Hydroelasticity
Wedge (geometry)
Impact
Impact pressure
Cite
Citations (30)
Slamming
Hydroelasticity
Impact pressure
Offshore geotechnical engineering
Added mass
Cite
Citations (163)
Based on Von Karman slamming theory,the slamming pressure of two-dimensional section with arbitrary shape is studied and the numerical method presented is applied to the slamming pressure calculation for two-dimensional trimaran section in this paper.Firstly,with the water entry velocity of a two-dimensional section assumed known,the added masses at different water entry depth can be calculated by means of source-sink distribution method.And then the change rate of added mass with water entry depth can be obtained.Finally,the slamming pressure can be calculated.The feasibility of this method is demonstrated by taking a two-dimensional wedge as an example.The slamming coefficient of two-dimensional wedge with different deadrise angle is calculated by using this method.The calculated results coincide well with the experimental data when the deadrise angle is larger than 10°.Furthermore,the slamming pressure calculation for two-dimensional trimaran section is studied with the numerical method.
Slamming
Wedge (geometry)
Impact pressure
Hydroelasticity
Cite
Citations (1)
Among all kinds of loads that floating and fixed marine constructions experience, water wave slamming can be considered as one of the most critical. To prevent naval constructions from failing due to slamming impact, slamming loads should be carefully investigated. Besides analytical and numerical calculations, experimental data is of crucial importance. Slamming loads can be measured by performing pressure measurements on the surface of the object during impact. Previous publications showed that precise and correct measurements are very difficult to perform, especially for slamming events with small deadrise angles. Large scatter mostly characterizes these measurements. This research focuses on improving the accuracy and reproducibility of the pressure recordings. Therefore, slamming drop tests are performed on a rigid cylindrical body. Most attention is paid to the bottom of the cylinder where the deadrise angle is 0°.
Slamming
Impact pressure
Cite
Citations (2)
An explicit finite element method which is combined with the Arbitrary Lagrangian-Eulerian (ALE) algorithm is applied to forecast slamming loads during the structure entries into the water. By adjusting the contact parameter, the result of slamming force is improved and this result is compared with the corresponding experimental values to verify the numerical prediction method of slamming loads. By simulating the wedge into the water at a constant speed and evenly variable speed, the effect of the impact velocity on local slamming pressure and global slamming force is studied.
Slamming
Wedge (geometry)
Impact pressure
Impact
Cite
Citations (0)
In the first report, it is clarified that a small cargo ship of length 48m in ballast condition is subjected to large hogging moment due to bottom slamming. In this report, the strength of the ship at S. S. 7 against hogging moment is estimated with the help of experiments for a structural component. The collapsing strength of S. S. 7 is significantly reduced by the existence of bottom corrugations which may be caused by slamming previously. Bottom corrugations reduce the effective stiffness of the bottom plates and also the section modulus I/y for bottom. Compared with the value of hogging moment caused by slamming, the strength of the ship may be insufficient for preventing the structural failure of the ship, although it is much larger than the required strength against the bending moment expected by the linear conventional theory.
Slamming
Ballast
Cite
Citations (0)
Slamming is harmful to ships and the status of bow slamming in heeling is rarely studied. Because yacht heeling will inevitably occur when navigating in storm,it is necessary to be studied the effect of bow slamming. The slamming performance on the bow of a 40 m steel yacht was studied using numerical simulation method. Based on the validation of ship analysis model established to simulate the slamming process in two-dimensional,the influences of slamming pressure with different speeds and angles on yacht bow have been analyzed and exhibited by employing LS / DYNA finite element method. The comparison results can be a reference to predict the time- varying dynamics of bow slamming pressure,which is of great importance for the structure design and operating performance of yacht.
Slamming
Bow tie
Cite
Citations (0)
The objective of this paper is to analyze the structural dynamic buckling strength of bow structure of a 1,700 TEU container vessel subjected to slamming impact force using finite element method (FEM). The slamming impact load formula suggested by Lloyd’s Register (LR) is used to assess the reliable value of impact force acting on the bow structure. To determine the critical buckling strength of a structure, two methods were developed—a one-time thickness deformation method and a buckling failure method—and are suggested to be used in the future as an industry standard. Various reasons for the causes of structure buckling damage are discussed, including magnitude of impact load, impact duration time and wave impact pattern. The result demonstrates that impact force integration under impact force-time curve is one of the crucial factors for structure dynamic buckling assessment. In the consideration of structure design optimization, this study compares efficient solutions to increase the structure buckling strength. Additionally, this study provides a clear picture of structure dynamic buckling behavior under variant impact force; moreover, it offers the designer solutions to prevent the structure from buckling damage.
Slamming
Impact
Cite
Citations (7)