Design of a Flexible-Base Hinged Connector for Very Large Floating Structures

2018 ◽  
Author(s):  
Qijia Shi ◽  
Daolin Xu ◽  
Haicheng Zhang
Keyword(s):  
Dynamic Behavior ◽  
Element Model ◽  
Structure Design ◽  
Deformation Analysis ◽  
Strength Analysis ◽  
Floating Platform ◽  
Floating Structures ◽  
Design Loads ◽  
Flexible Base ◽  
Optimal Stiffness

Connector of multi-modular VLFS is a key component which determines the connection load and the dynamic behavior of the system. This paper presents a new design of the flexible-base hinged connector (FBHC) for VLFS in order to reduce the connection load. The connector consists of a hinged joint and two flexible bases. A finite element model of the connector is established for the deformation analysis to match up the requirement on the optimal stiffness combination of the connector [1]. Further the strength analysis is also carried out to check the safety of the structure design according to the maximum design loads. By applying the connector model to a three-modular floating platform, the dynamic behavior of the platform is analyzed. The results show that the responses of the modules are within the tolerable range and the connector meets the strength requirements.

Dynamic Behavior of Bi-Axial Self-Synchronous Shaker with Translation Elliptic Trace

2011 ◽  
Vol 211-212 ◽  
pp. 406-410
Author(s):  
Wei Bing Zhu ◽  
Cheng Zhong Deng ◽  
He Shun Wang
Keyword(s):  
Dynamic Behavior ◽  
Natural Frequencies ◽  
Dynamic Strength ◽  
Element Model ◽  
Maximum Principal Stress ◽  
Structure Design ◽  
Experiment Research ◽  
Design Improvement ◽  
Oscillation Modes ◽  
Stress And Deformation

According to the self-synchronous theory with two vibrating electric motors, a translation elliptic shaker is designed, and its finite element model for the sieving box is established. The dynamic behavior analysis of the sieving box is reached with CATIA software. The natural frequencies and modal oscillation modes of the sieving box are calculated, and the stress and deformation distribution in every part of the sieving box under rated load are obtained. All shows that, its structure design is reasonable. Under the designed working conditions, the maximum principal stress of the side boards is 39.7 MPa, and its dynamic strength is satisfied. The calculating results will be of significance to the design improvement, and give a basis for the experiment research of dynamic strength.

Global Structure Strength Analysis of SWATH Based on Direct Calculate Method

2014 ◽  
Vol 633-634 ◽  
pp. 1002-1006
Author(s):  
Chun Bo Zhen ◽  
Liang Feng ◽  
Guo Chun Lu ◽  
Yuan Hang Hou
Keyword(s):  
Stress Concentration ◽  
Boundary Conditions ◽  
Element Model ◽  
Global Structure ◽  
Strength Analysis ◽  
Response Analysis ◽  
Structure Response ◽  
Result Show ◽  
Design Loads ◽  
Structure Strength

The stress concentration of SWATH’s cross-deck structure is serious and the problem of its structure strength appears particularly important. In this paper, A 3-D global element model of SWATH was built, the design Loads, load cases and boundary conditions were studied. on the base of that, the structure response analysis was completed. The result show that the global ship’s stress is small in all load cases of head seas and oblique seas, and the bulkheads have serious stress concentration phenomenon in beam seas.The result can offer the reference for SWATH’s design and development.

scholarly journals Optimal Design for the Structure Parameters of Long Raster Engraving Air-floating Platform

Mechanika ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 55-63
Author(s):  
Deyun Mo
Keyword(s):  
Film Thickness ◽  
Element Model ◽  
Structure Design ◽  
Test Method ◽  
Loading Capacity ◽  
Three Dimension ◽  
Floating Platform ◽  
Range Analysis ◽  
Orthogonal Test Method ◽  
Air Film

Air-floating platform is the core component of long raster engraving system. In order to design an air-floating platform to greatly meet the demands of long raster engraving, this paper, based on the validation of simulation model accuracy by test platform, proposes a three-dimension finite element model about gas film, and investigates the influence of the gas film thickness, air pressure and width of bottom guideway on the loaded capacity and air consumption by orthogonal test method. Then the best design plan of air-floating platform structure was determined by range analysis method. The results showed that air film thickness H=0.02 mm, gas supply pressure Ps=0.15 MPa, width of bottom guideway Bx=140 mm, the loading capacity of single-sided guideway is about 3177 N, its air consumption is 191487 mm3/s. Hence, this plan can not only meet the requirements of the loading capacity but also reduce air consumption of air-floating platform so as to provide a basis for optimum structure design about air-floating platform.

scholarly journals Stress and Deformation Analysis of Buried Gas Pipelines Subjected to Buoyancy in Liquefaction Zones

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2334 ◽  
Author(s):  
Mengying Xia ◽  
Hong Zhang
Keyword(s):  
Analytical Model ◽  
Safety Evaluation ◽  
Element Model ◽  
Deformation Analysis ◽  
Strength Analysis ◽  
Gas Pipelines ◽  
Long Distance ◽  
Axial Forces ◽  
And Performance ◽  
Buried Gas Pipeline

Buried pipelines are the main means of long distance transportation of natural gas. These pipelines are in high risk crossing liquefaction areas due to large deformations and stresses that may exist in pipe induced by the buoyancy load. In this study, a systematic analytical and numerical analysis were performed to investigate the mechanical behavior of a buried gas pipeline subjected to buoyancy in liquefaction areas. Soil constraints on pipe were considered accurately in the proposed models through soil spring assumptions. Effects of axial forces on pipe’s bending deformation were also considered via the governing equations for beam under bending and tension. Deformation compatibility condition was utilized to derive the axial forces in pipe. The accuracy of the proposed analytical model was validated by comparing its results with those derived by an established rigorous finite element model. In addition, parametric analysis was finally performed using the analytical model to study the influences of pipe diameter, pipe wall thickness, soil spring stiffness and width of liquefaction zone on pipe’s mechanical responses. This study can be referenced in the strength analysis and performance based safety evaluation of buried gas pipelines crossing liquefaction areas.

scholarly journals The Strength Analysis of a Bus Superstructure Based on the Accuracy Improvement of T-Junction Flexible Joint Stiffness

2018 ◽  
Vol 7 (3.24) ◽  
pp. 62
Author(s):  
Supakit Rooppakhun ◽  
Jakkree Wichairahad
Keyword(s):  
Maximum Stress ◽  
Joint Stiffness ◽  
Element Model ◽  
Lateral Load ◽  
Joint Model ◽  
Structure Design ◽  
Strength Analysis ◽  
Fe Model ◽  
Accuracy Improvement ◽  
Flexible Joint

The strength analysis of bus superstructure was extremely important that the manufacturer must take into account, especially in the maximum stress analysis as well as the construction stiffness. In this study, the finite element (FE) model of an intercity bus superstructure consisted of chassis frame and body structure has been analyzed based on the improved beam joint considerations. The accuracy improvement of beam type element model was performed using the equivalent joint stiffness of T-junction beam modeling, and then compared with shell and volume elements. According to the improved T-junction FE model, the flexible joint stiffness consideration has been obtained, in which the behavioral error was reduced to less than 6%. The FE model of bus superstructure with improved beam joint was then compared to the rigid joint condition in bending, torsion, longitudinal and lateral load cases. The numerical results revealed that magnitude of maximum stress in the improved beam joint model displayed increasing of 11.53 %, 14.11 %, and 18.45 % in torsion, longitudinal and lateral load cases, respectively. However, the maximum stresses reduced in a case of bending with value of 5.72 %. In addition, the value of construction stiffness of improved beam joint model exhibited lower than the rigid beam joint as 44.85%, and 10.68% in the bending and torsion load case, respectively. To improve the accuracy of computer simulation, it will be beneficial to the passenger and the bus structure design and improvement procedure. 

Dynamic Characteristics Analysis of Cable-Rib Tension Deployable Antenna

2016 ◽  
Author(s):  
Liu Ruiwei ◽  
Hongwei Guo ◽  
Zhang Qinghua ◽  
Rongqiang Liu ◽  
Tang Dewei
Keyword(s):  
Dynamic Characteristics ◽  
Structural Parameters ◽  
Element Model ◽  
Structure Design ◽  
Antenna Structure ◽  
Characteristics Analysis ◽  
New Type ◽  
Dynamic Characteristics Analysis ◽  
The Finite Element Model ◽  
Weight Dynamic

Balancing stiffness and weight is of substantial importance for antenna structure design. Conventional fold-rib antennas need sufficient weight to meet stiffness requirements. To address this issue, this paper proposes a new type of cable-rib tension deployable antenna that consists of six radial rib deployment mechanisms, numerous tensioned cables, and a mesh reflective surface. The primary innovation of this study is the application of numerous tensioned cables instead of metal materials to enhance the stiffness of the entire antenna while ensuring relatively less weight. Dynamic characteristics were analyzed to optimize the weight and stiffness of the antenna with the finite element model by subspace method. The first six orders of natural frequencies and corresponding vibration modes of the antenna structure are obtained. In addition, the effects of structural parameters on natural frequency are studied, and a method to improve the rigidity of the deployable antenna structure is proposed.

Launching of Ships and Floating Structures from Horizontal Berth by Tipping Table

1998 ◽  
Vol 14 (04) ◽  
pp. 265-276
Author(s):  
Ivo Senjanovic
Keyword(s):  
Structural Dynamics ◽  
Review Paper ◽  
Offshore Structures ◽  
Model Tests ◽  
Full Scale ◽  
Strength Analysis ◽  
Test Results ◽  
Floating Structures ◽  
Measurement Results

This review paper covers extensive investigations which were undertaken in order to verify the idea of launching of ships and other floating structures from a horizontal berth by a set of turning pads. This includes structural dynamics during launching, model tests and strength analysis of the structure and the launching system. The most important results, which were used for the design of the launching system, are presented. The preparation of a barge for side launching is described, and the full-scale measurement results are compared with the test results. The advantages of building ships and offshore structures on a horizontal berth are pointed out in the conclusion.

Estimating Design Loads for Floating Structures Using Environmental Contours

2021 ◽  
Author(s):  
Sheng Dong ◽  
Yuliang Zhao ◽  
Zihao Yang ◽  
Lance Manuel
Keyword(s):  
Floating Structures ◽  
Design Loads

A Flexible Connector Design for Multi-Modular Floating Structures

2018 ◽  
Author(s):  
Huai Zhao ◽  
Daolin Xu ◽  
Haicheng Zhang ◽  
Qijia Shi
Keyword(s):  
Finite Element Method ◽  
Structural Model ◽  
Random Waves ◽  
The Finite Element Method ◽  
Floating Platform ◽  
Stiffness Analysis ◽  
Floating Structures ◽  
Extreme Loads ◽  
Strength And Stiffness ◽  
Frequency Domain Approach

The paper aims to provide a novel flexible connector model for the connection of a multi-modular floating platform. The structural model of the connector is presented. To evaluate connector loads, the governing equation for a modularized floating platform is established using the Rigid Module Flexible Connector (RMFC) model. The dynamic analysis for a two-module floating platform is carried out by using the frequency domain approach in random waves and the extreme loads of the flexible connector are estimated. The finite element method is applied for strength and stiffness analysis to assess the performance of the connector.

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