Offshore Structure Response due to Ship Collision on Jacket Legs

2014 ◽  
Vol 66 (2) ◽  
Author(s):  
Agustin Dwi Sumiwi ◽  
Efi Afrizal ◽  
Jaswar Jaswar ◽  
Handayanu Handayanu
Keyword(s):  
Research Result ◽  
Local Deformation ◽  
Normal Velocity ◽  
Offshore Structure ◽  
Tidal Variation ◽  
Maximum Displacement ◽  
Structure Damage ◽  
Landing Platform ◽  
Global Deformation

This paper discusses graded and collision velocity supply vessel influence to local and global structure damage subject to collision. This case study for CONOCO BELANAK wellhead platform that approaching with of 2500 tonnes of supply vessel with tidal variation for each collision scenario. Deformation of the jacket leg occurs causes by material inability to proof against pressure. This paper uses 2 software are ANSYS LS-DYNA 9.0 to acquire local deformation and GT-STRUDL 27.0 version to acquire global deformation included dynamic transient analysis. Outside diameter of Jacket Leg is 1.651 m with wall thickness is 0.0381 m. Normal velocity in each sideway, stern; manoeuvring collision and extreme velocity is 0.28 m/s, 0.39 m/s and 0.74. Extreme velocity in each sideway and stern collision is and 10% exceedance velocity is 0.54 m/s, 0.73 m/s and 1.29 m/s. The result of this paper is dent of the landing platform for each normal and extreme is 0.2725 m, 0.2352 m, and 0. 3241 m/s it must be repaired or changed because of it is 30% larger than spacing frame. Maximum displacement x, y, z direction is 0.2423 m on 0.38 s, 0. 0559 m on 0.39 s, 0.7492 m on 0.41 s. The deformation in landing platform, jacket leg and jacket structure is smaller than research result indeed.

scholarly journals Cooperative Control Mechanism of Long Flexible Bolts and Blasting Pressure Relief in Hard Roof Roadways of Extra-Thick Coal Seams: A Case Study

2021 ◽  
Vol 11 (9) ◽  
pp. 4125
Author(s):  
Zhe Xiang ◽  
Nong Zhang ◽  
Zhengzheng Xie ◽  
Feng Guo ◽  
Chenghao Zhang
Keyword(s):  
Coal Seam ◽  
Cooperative Control ◽  
Field Tests ◽  
Surrounding Rock ◽  
Deep Hole ◽  
Coal Seams ◽  
Thick Coal Seam ◽  
Structure Damage ◽  
Hard Roof

The higher strength of a hard roof leads to higher coal pressure during coal mining, especially under extra-thick coal seam conditions. This study addresses the hard roof control problem for extra-thick coal seams using the air return roadway 4106 (AR 4106) of the Wenjiapo Coal Mine as a case study. A new surrounding rock control strategy is proposed, which mainly includes 44 m deep-hole pre-splitting blasting for stress releasing and flexible 4-m-long bolt for roof supporting. Based on the new support scheme, field tests were performed. The results show that roadway support failure in traditional scenarios is caused by insufficient bolt length and extensive rotary subsidence of the long cantilever beam of the hard roof. In the new proposed scheme, flexible 4-m-long bolts are shown to effectively restrain the initial expansion deformation of the top coal. The deflection of the rock beam anchored by the roof foundation are improved. Deep-hole pre-splitting blasting effectively reduces the cantilever distance of the “block B” of the voussoir beam structure. The stress environment of the roadway surrounding rock is optimized and anchorage structure damage is inhibited. The results provide insights regarding the safe control of roadway roofs under extra-thick coal seam conditions.

Hull Deformation Effect on Membrane-Type LNG Containment Systems

2016 ◽  
Author(s):  
Bo Wang ◽  
Yung-Sup Shin ◽  
Eric Norris
Keyword(s):  
Structural Integrity ◽  
Water Pressure ◽  
Local Deformation ◽  
Fatigue Tests ◽  
Wave Loads ◽  
Insulation System ◽  
Structural Fatigue ◽  
Hull Structure ◽  
Membrane Type ◽  
Global Deformation

The objective of this study is to investigate the relationship between the maximum allowable hull deformation, which includes global elongation and local deflection, and the capacity of the CCS in membrane-type LNG vessels. The LNG CCS mainly consists of the primary barrier (e.g. a corrugated membrane for GTT MK III system and an invar membrane for GTT NO 96 system) and the insulation panel which is attached to the inner hull through mastics or couplers. The excessive hull elongation due to dynamic wave loads may cause fatigue damage of the primary barrier. Thus, the maximum allowable hull elongation (global deformation) can be determined based on the fatigue strength of the primary barrier. On the other hand, the excessive hull deflection due to cargo or ballast water pressure may cause failure of the insulation panel and the mastic. Therefore, the maximum allowable hull deflection (local deformation) in the hull design can be determined based on the strength of the insulation panel and the mastic. In the present paper, the determination of fatigue life vs. strain curves of materials has been summarized for the primary barrier. Fatigue curves based on either structural fatigue tests or standard specimen tests can be applied in fatigue assessment of a primary barrier. As an example, the finite element (FE) analysis has been conducted on the MK III CCS with the hull structure under pressure loads. Two different load cases including full load and ballast load conditions have been considered to evaluate the structural integrity of the insulation system in numerical simulations. FE results show that the mechanical behavior of the insulation system and the mastic under the maximum allowable hull deflection has been examined based on the yielding strength of each individual component. Finally, the complete procedure to determine the maximum allowable hull elongation and the maximum allowable hull deflection has been developed for meeting the requirements of containment system design for membrane-type LNG carriers.

scholarly journals New Media Technology in Developing Effective Organizational Internal Communication

Humaniora ◽  
2017 ◽  
Vol 8 (1) ◽  
pp. 21
Author(s):  
Nur Kholisoh ◽  
Ria Sulastri
Keyword(s):  
New Media ◽  
Computer Mediated Communication ◽  
Research Result ◽  
Internal Communication ◽  
Communication Pattern ◽  
Media Technology ◽  
Mediated Communication ◽  
Media Communication ◽  
Computer Mediated

The article was intended to investigate various benefits of Whatsapp Messenger application for an effective intenal communication in PT Euro Management Indonesia. In addition, this research also aimed to map the organizational internal communication pattern through the use of Whatsapp Messenger application. The research used theories of organizaional communication, new media communication pattern, and computer mediated communication (CMC). Moreover, paradigm used in the research was constructivist with qualitative approach and the research method was case study. The research result finds that the use of new media Whatsapp Messenger as a tool of communication can build effective internal communication in PT Euro Management Indonesia. Moreover, it also shows that the internal organizational communication pattern in PT Euro Management Indonesia used in Whatsapp Messenger application is conversation pattern.

scholarly journals PENGARUH DEBT TO ASSET RATIO, PERPUTARAN KAS DAN RASIO LANCAR TERHADAP PROFITABILITAS PADA SUB SEKTOR PROPERTY AND REAL ESTATE YANG TERDAFTAR DI BURSA EFEK INDONESIAPERIODE 2014-2016

2018 ◽  
Vol 3 (1) ◽  
pp. 138
Author(s):  
Meilani Ong ◽  
Widya Sari ◽  
Laura Veronica ◽  
Viena Valen Sijabat
Keyword(s):  
Real Estate ◽  
Research Method ◽  
Sampling Method ◽  
Stock Exchange ◽  
Research Result ◽  
Current Ratio ◽  
Financial Reports ◽  
Property Companies ◽  
Turn Over

The purpose of this study is to analize the influence of debt to asset ratio, cash turn over and current ratio on profitability of case study in real estate and property companies listed on indonesia stock exchange from 2014 until 2016.The sample of this study was eighty one  financial  reports which contain twenty seven companies with years of observation for three years by using purposive sampling method.  The  research  method  used  is  descriptive  quantitative  analysis  by using   multiple   regression   analysis.Based   on   the   research   result,   it   can   be   concluded   that   debt to asset ratio,cash turn over and current ratio have no influence toward profitability partially.

scholarly journals PEREKONOMIAN PARIWISATA ISLAMI TERHADAP PEDAGANG DI KAWASAN MAKAM SUNAN KALIJAGA

2019 ◽  
Vol 5 (6) ◽  
pp. 513
Author(s):  
Galih Caesario Rahman ◽  
Sunan Fanani
Keyword(s):  
Data Analysis ◽  
Data Collection ◽  
Research Method ◽  
Economic Condition ◽  
Research Result ◽  
Case Study Method ◽  
Descriptive Case Study ◽  
Data Presentation ◽  
Tourism Activity

This study aims to figure how is the dynamic or economic condition change caused by the existence of Islamic tourism of Sunan Kalijaga Tomb to stall sellers who most of them are the locals lives around the Islamic tourism of Sunan Kalijaga tomb. The research method used is descriptive case study method. Where the data collection done by interview and observation. In this research, the informant is the parties involved in the tourism activity, which is the seller, the visitor, and the worker around the Islamic tourism of Sunan Kalijaga tomb, Demak District. The data analysis used is data reduction, data presentation, and make a conclusion.The research result suggests that the existence of Islamic tourism of Sunan Kalijaga tomb Demak District brings economical change towards the seller works around.

Finite Element Analysis of Mechanics Property on Memory Alloy Patella Claws with Anti-Shearing Force

2014 ◽  
Vol 635-637 ◽  
pp. 507-510
Author(s):  
Dong Peng Du ◽  
Zhe Wu ◽  
Juan Xing ◽  
Xiao Yan Gong ◽  
Xiang Wen Miu ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Mechanical Performance ◽  
Tensile Force ◽  
Research Result ◽  
Element Model ◽  
3D Models ◽  
Shearing Force ◽  
Maximum Displacement ◽  
Element Analysis

When strong exercise on human being body, respectively, under knees 30°, 60°,90°, using PRO/E5.0 software to establish the transverse patella fracture and anti-shearing force patella claws 3D models, then the two structure models were assembled and imported into ABAQUS10.1 software to establish the finite element model of patellar fracture fixed within patella claw, and analyzed the mechanical performance in perforce finite element model. Under the same boundary conditions, the maximum displacement and deformation of each components were different at every flexion angle. Compared with anti-shearing force patella claw and AO tensile force girdle, the patella claw with stronger resistance to tension and anti-shearing force was more stable. Deformation and displacement of patella claw in accordance with biomechanical research result that is needed by clinical. Its stability will satisfy clinical requirements for functional exercise.

Modelling Techniques and Case Study of Explicit 3D FE-Simulation of Ridge Loads Against an Offshore Structure

2009 ◽  
Author(s):  
Jaakko Heinonen
Keyword(s):  
Friction Angle ◽  
Material Model ◽  
Dimensional Structure ◽  
Constant Thickness ◽  
Fe Model ◽  
Offshore Structure ◽  
3 Dimensional ◽  
Modelling Techniques ◽  
User Material Subroutine

A ridge interaction with an offshore structure, Norstro¨msgrund lighthouse in the Gulf of Bothnia, was simulated by the finite element method (FEM) utilizing the explicit solution algorithm. The explicit method in a dynamic analysis enabled an efficient way to simulate the failure of a ridge. A shear-cap material model describing the ice rubble mechanical behaviour was developed for the 3-dimensional analysis and implemented into ABAQUS FEM-software as a user material subroutine. The FE-model described the ridge: the sail and keel consisting of ice rubble and the consolidated layer close to the waterline. A selected ridge-interaction event was simulated with a simplified geometry, based on measurements carried out in the STRICE project. The ridge field was idealized to have a constant thickness. The shape of a 3-dimensional structure was modelled using rigid elements. The phenomenological model can be utilized to gain an understanding of how the ridge fails during the interaction with an offshore structure, what the ridge loads are, and how they are distributed against the structure. A parametric study was carried out to study how the mechanical properties, i.e. the cohesion and friction angle of the rubble and the strength of the consolidated layer influence the forces and failure mechanisms.

Integrity Management System for Fixed Offshore Structures Inspection Strategy

2004 ◽  
Author(s):  
Mohamed A. El-Reedy
Keyword(s):  
Management System ◽  
Offshore Structures ◽  
Assessment Method ◽  
Offshore Platforms ◽  
Offshore Structure ◽  
Structure Comparison ◽  
Actual Structure ◽  
Existing Structures ◽  
Integrity Management

The GUPCO offshore structure management system was developed as a part of an integrated infrastructure management system. This paper presents a case study of providing an integrity management system for inspection, evaluation and repair of the fixed offshore platforms in Gulf of Suez. The management system procedure is presented focusing on the first step for defining the highly risky weight to the lower risky weight structure based on API criteria for assessment of the existing structures. The risk analysis methodology for developing design and assessment criteria for fixed offshore structure based on consequence of failure is illustrated. In our case study the assessment method is applied for a number of fixed offshore structures. The above methodology is performed after theoretical assessment and then verifying by using ROV subsea inspection for the fixed offshore structure. Comparison between the actual structure performance and the predicting risk assessment for the structure from the model will be studied. The overall management system will be illustrated in scope of predictive maintenance philosophy and reliability for all offshore structures.

scholarly journals Efficiency of Using Tuned Mass Damper to Reduce Damage after Strong Earthquakes

2018 ◽  
Vol 239 ◽  
pp. 05014
Author(s):  
Andrei Benin ◽  
Alexander Uzdin ◽  
Olga Nesterova
Keyword(s):  
Plastic Deformation ◽  
Spectral Composition ◽  
Tuned Mass Damper ◽  
Seismic Action ◽  
Loading History ◽  
Maximum Displacement ◽  
Strong Earthquakes ◽  
Structure Damage ◽  
Damage Degree ◽  
Mass Damper

The efficiency of applying tuned mass damper is substantiated for reducing the damageability of structures under strong earthquakes. Two models of structure damage accumulation are considered. The first model is elastoplastic one, the damage degree of the model being determined by the work of plastic deformation forces. The second model is a model with degrading rigidity the damage degree of the model is connected with the development of cracks and is determined by the maximum displacement of the structure in its loading history. For the first type of nonlinearity, i.e. the first model there is an amplitude-frequency characteristic and the optimum tuning of the mass damper corresponds to the maximum of this characteristic. For the second model of accumulation of damages there is no frequency response, therefore the mass damper tuning obtained with harmonic action on the elastic system was used. Calculations of the system with mass damper and without it using earthquake accelerograms have been carried out. Accelerograms, the most unfavorable in terms of the spectral composition for the structures under consideration, were chosen taking into account peak accelerations and energy characteristics of the seismic action. It has been established for elastoplastic systems that tuned mass damper reduces the time of the structure being in plastic stage and the work of plastic deformation forces. For systems with degrading stiffness tuned mass damper reduces the maximum movement of the system in its loading history.

The Development of an APT Program Interpreter for 5-Axis Machining

2012 ◽  
Vol 482-484 ◽  
pp. 2247-2252 ◽  
Author(s):  
Hsin Yu Cheng ◽  
Jo Peng Tsai ◽  
Yung Chou Kao
Keyword(s):  
Research Result ◽  
Value Added ◽  
Working Process ◽  
Nc Code ◽  
Cad Cam ◽  
Cutter Orientation ◽  
Advanced Machining ◽  
Five Axis ◽  
Cam Software

As there are various machine configuration and frequent changes of cutter orientation in 5-axis machining, the standard NC codes are not inter-exchangeable among machines. This phenomenon induces a lot of cutting difficulties and machining problems such as the inconvenient working process for operators and very low cutting efficiency. At present, some advanced machine controllers already can accept the APT code besides NC code to increase the cutting flexibility. They also offer some advanced machining functions such as tool center point control and spatial compensations of tool, etc. By way of APT interpreting, the common controller can also implement these advanced functions. Besides, CAD/CAM software also supports APT post-processor to generate NC code for different machine configurations. This means the application of ATP program has played an important role in five-axis machining. However, although CAD/CAM software supports the interpretation of APT program as a core key technology of five-axis machining, the manufacturers of controller with advanced functions are unwilling to open their system. Up to now, there has been few related research papers published on this topic. In this paper, we proposed an APT interpretation method for five-axis machining. This method includes seven functional modules and related implementing procedures. A case study has been adopted to demonstrate the feasibility of the proposed method. The research result could be adopted as a reference to develop the value-added technology in 5-axis machine tool application for academy and industry.

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