scholarly journals General Concerns Life-Cycle Design of Economical Ice-Resistant Structures in the Bohai Sea

2017 ◽  
Vol 24 (s2) ◽  
pp. 164-171
Author(s):  
Da-yong Zhang ◽  
Song-song Yu ◽  
Qian-jin Yue
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Design Theory ◽  
Bohai Sea ◽  
Cost Effective ◽  
Bohai Bay ◽  
Offshore Platforms ◽  
The Bohai Sea ◽  
Life Cycle Design ◽  
Whole Life Cycle

Abstract In China, the oil and natural gas resources of Bohai Bay are mainly marginal oil fields. It is necessary to build both iceresistant and economical offshore platforms. However, there are many risks during the life cycle of offshore platforms due to the imperfect preliminary design for the Bohai Sea economical ice-resistant structures. As a result, the whole life-cycle design should be considered, including plan, design, construction, management and maintenance design. Based on the demand of existing codes and research of the basic design, structural ice-resistant performance and the reasonable management and maintenance, the life-cycle design theory is discussed. It was concluded that the life-cycle cost-effective optimum design proposed will lead to a minimum risk.

Life-Cycle Cost-Effective Optimum Design of Ice-Resistant Offshore Platforms

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Gang Li ◽  
Dayong Zhang ◽  
Qianjin Yue
Keyword(s):  
Life Cycle ◽  
Optimum Design ◽  
Life Cycle Cost ◽  
Failure Modes ◽  
Cost Effective ◽  
Design Model ◽  
Cost Evaluation ◽  
Bohai Bay ◽  
Offshore Platforms ◽  
Dynamic Reliability

In China, the oil and natural gas resources in Bohai Bay are mainly marginal oil fields, which freeze in the winter. It is necessary to build both ice-resistant and economical offshore platforms. However, risk is involved in the design, construction, utilization, and maintenance of offshore platforms as uncertain events may occur within the life-cycle of a platform. In this paper, the optimum design model of the expected life-cycle cost for ice-resistant platforms based on the cost-effectiveness criterion is proposed. Multiple performance demands of the structure, facilities and crew members, associated with the failure assessment criteria and evaluation functions of costs of construction, consequences of structural failure modes including damage, revenue loss, death, and injury, as well as discounting cost over time are considered. Different reliability analysis approaches involved in life-cycle cost evaluation, such as the global reliability under the extreme ice load, the dynamic reliability, and fatigue life induced by ice vibration, are studied. The proposed life-cycle optimum design formulas are applied to a typical ice-resistant platform in Bohai Bay, and the results demonstrate that the life-cycle cost-effective optimum design model is more rational compared with the conventional static design and the optimum dynamic design.

scholarly journals Storm Surges in the Bohai Sea: The Role of Waves and Tides

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1509
Author(s):  
Yuanyi Li ◽  
Huan Feng ◽  
Guillaume Vigouroux ◽  
Dekui Yuan ◽  
Guangyu Zhang ◽  
...  
Keyword(s):  
Storm Surge ◽  
Bohai Sea ◽  
Storm Surges ◽  
Wave Force ◽  
Laizhou Bay ◽  
Bohai Bay ◽  
Coastal Regions ◽  
The Bohai Sea ◽  
Tidal Phase ◽  
Set Up

A storm surge is a complex phenomenon in which waves, tide and current interact. Even though wind is the predominant force driving the surge, waves and tidal phase are also important factors that influence the mass and momentum transport during the surge. Devastating storm surges often occur in the Bohai Sea, a semi-enclosed shallow sea in North China, due to extreme storms. However, the effects of waves on storm surges in the Bohai Sea have not been quantified and the mechanisms responsible for the higher surges that affect part of the Bohai Sea have not been thoroughly studied. In this study, we set up a storm surge model, considering coupled effects of tides and waves on the surges. Validation against measured data shows that the coupled model is capable of simulating storm surges in the Bohai Sea. The simulation results indicate that the longshore currents, which are induced by the large gradient of radiation stress due to wave deformation, are one of the main contributors to the higher surges occurring in some coastal regions. The gently varying bathymetry is another factor contributing to these surges. With such bathymetry, the wave force direction is nearly uniform, and pushes a large amount of water in that direction. Under these conditions, the water accumulates in some parts of the coast, leading to higher surges in nearby coastal regions such as the south coast of the Bohai Bay and the west and south coasts of the Laizhou Bay. Results analysis also shows that the tidal phase at which the surge occurs influences the wave–current interactions, and these interactions are more evident in shallow waters. Neglecting these interactions can lead to inaccurate predictions of the storm surges due to overestimation or underestimation of wave-induced set-up.

scholarly journals Sustainable Ventilation Strategies for a Medium-Sized Space with Regional Effect

2021 ◽  
Vol 13 (9) ◽  
pp. 4651
Author(s):  
Ming-Lun Alan Fong
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Co2 Emission ◽  
High Efficiency ◽  
Regional Climate ◽  
Cost Effective ◽  
Regional Effect ◽  
Climate Conditions ◽  
Ventilation Strategies ◽  
Set Up

The analysis of ventilation strategies is fundamentally affected by regional climate conditions and local cost databases, in terms of energy consumption, CO2 emission and cost-effective analysis. A systematic approach is covered in this paper to estimate a local economic and environmental impact on a medium-sized space located in two regions during supply-and-installation and operation phases. Three ventilation strategies, including mixing ventilation (MV), displacement ventilation (DV) and stratum ventilation (SV) were applied to medium-sized air-conditioned space with this approach. The trend of the results for three ventilation systems in the life cycle assessment (LCA) and life cycle cost (LCC) analysis is SV < DV < MV. The result of CO2 emission and regional LCC shows that SV is the lowest one in both regional studies. In comparison with the Hong Kong Special Administrative Region (HKSAR) during 20 Service years, the case analysis demonstrates that the percentage differences in LCC analysis of MV, DV & SV in Guangdong are less than 20.5%, 19.4% and 18.82% respectively. Their CO2 emission of MV, DV and SV in Guangdong are more than HKSAR in 10.69%, 11.22% and 12.05%, respectively. The present study could provide information about regional effects in the LCA and LCC analysis of three ventilation strategies emissions, and thereby help set up models for decision-making on high efficiency and cost-effective ventilation strategy plans.

scholarly journals Spatio-temporal characteristics of the sea-ice volume of the Bohai Sea, China, in winter 2009/10

2013 ◽  
Vol 54 (62) ◽  
pp. 97-104 ◽  
Author(s):  
Chengyu Liu ◽  
Wei Gu ◽  
Jinlong Chao ◽  
Lantao Li ◽  
Shuai Yuan ◽  
...  
Keyword(s):  
Sea Ice ◽  
Bohai Sea ◽  
Shortwave Radiation ◽  
Laizhou Bay ◽  
Bohai Bay ◽  
Temporal Characteristics ◽  
The Bohai Sea ◽  
Ice Volume ◽  
Radiation Theory ◽  
Spatio Temporal

AbstractTo investigate the spatio-temporal characteristics of sea-ice resource, we used sea-ice volume to measure the amount of sea-ice resource in the Bohai Sea, China. The sea-ice area was extracted from Advanced Very High Resolution Radiometer (AVHRR) remote-sensing images using the zonal threshold method. The sea-ice thickness was estimated using a sea-ice model based on shortwave radiation theory and field measurements. The spatio-temporal characteristics of sea-ice volume were then analysed using GIS technology. The results indicate that the Bohai Sea experienced two sea-ice volume peaks in winter 2009/10. The largest sea-ice volume was in Liaodong Bay (∼80.26% of the entire sea-ice volume of the Bohai Sea). Bohai Bay had the second largest ice volume, and Laizhou Bay the smallest. The relationship between sea-ice volume and distance from shore is essentially exponential. The proportion of total sea-ice volume that is 0–10 km from shore is ∼42.43%, whereas the proportion that is 100–110 km from shore is only 0.002%.

Comparison of environmental performance between plastic and steel fuel tanks

2002 ◽  
Vol 216 (11) ◽  
pp. 1443-1457 ◽  
Author(s):  
C-y Tung ◽  
M H Wang
Keyword(s):  
Life Cycle ◽  
Product Design ◽  
Environmental Performance ◽  
Early Stage ◽  
Environmentally Conscious ◽  
Performance Technique ◽  
Life Cycle Design ◽  
Fuel Tanks ◽  
Environmentally Conscious Design ◽  
Whole Life Cycle

Increasing awareness of environmental burdens has led companies and designers to initiate design for the environment (DFE) programmes, which consider the design of products from the ‘cradle to grave’ and is also known as ‘life-cycle design’. In this paper, the use of a novel environmental performance technique to be used at the early stage of product design is presented. This technique, which is to be used as a framework for green product design, is demonstrated in this paper by evaluating the environmental performance between plastic and steel fuel tanks. The fuel tank comparison can be divided into five steps. In the first four steps, a modified house of quality (HOQ) is used to analyse the performance of fuel tanks in terms of requirements of environmentally conscious design. The final step is an overall assessment that synthesizes the results from the previous four analyses. As a result, the comprehensive environmental effects in the whole life cycle of fuel tanks are captured in the early stage of design.

A Model for Making Part Sourcing Decisions for Long Life Cycle Products

2011 ◽  
Author(s):  
Varun J. Prabhakar ◽  
Peter Sandborn
Keyword(s):  
Supply Chain ◽  
Life Cycle ◽  
Life Cycle Cost ◽  
Critical Infrastructure ◽  
Cost Effective ◽  
Sourcing Strategies ◽  
Support Costs ◽  
Long Life ◽  
Sourcing Decisions ◽  
Linear Regulators

Long life cycle products, commonly found in aviation, medical and critical infrastructure applications, are often fielded and supported for long periods of time (20 years or more). The manufacture and support of long life cycle products rely on the availability of suitable parts, which over long periods of time, leaves the parts susceptible to a number of possible supply chain disruptions such as suppliers exiting the market, counterfeit part risks, and part obsolescence. One solution to mitigating the supply chain risk is the strategic formulation of suitable part sourcing strategies (optimally selecting one or more suppliers from which to purchase parts over the life of the part’s use within a product or within an organization). Strategic sourcing offers one way of avoiding the risk of part unavailability (and its associated penalties), but at the possible expense of qualification and support costs for multiple suppliers. Existing methods used to study part sourcing decisions are procurement-centric where cost tradeoffs focus on part pricing, negotiation practices and purchase volumes. These studies are commonplace in strategic parts management for short life cycle products; however, conventional procurement-centric approaches offer only a limited view when assessing parts used in long life cycle products. Procurement-driven decision-making provides little to no insight into the accumulation of life cycle cost (attributed to the adoption and use of the part), which can be significantly larger than procurement costs in long life cycle products. This paper presents a new life cycle modeling approach to quantify risk that enables cost effective part sourcing strategies. The method quantifies obsolescence risk as “annual expected total cost of ownership (TCO) per part site” modeled by estimating the likelihood of obsolescence and using that likelihood to determine the TCO allowing sourcing strategies to be compared on a life cycle cost basis. The method is demonstrated for electronic parts in an example case study of linear regulators and shows that when procurement and inventory costs are small contributions to the part’s TCO, the cost of qualifying and supporting a second source outweighs the benefits of extending the part’s effective procurement life.

scholarly journals Predication of life cycle cost of equipment base on unbiased grey Markov models

2020 ◽  
Vol 309 ◽  
pp. 05005
Author(s):  
Yonghong Chen ◽  
Ping Hu ◽  
Dong Zhang
Keyword(s):  
Life Cycle ◽  
Markov Model ◽  
Life Cycle Cost ◽  
Prediction Accuracy ◽  
Markov Models ◽  
Grey Model ◽  
Model Accuracy ◽  
Integrated Logistics ◽  
And Control ◽  
Whole Life Cycle

Life cycle cost(LCC) is an important content of equipment integrated logistics support. While the LCC includes the whole life cycle of equipment from development, production, service and maintenance to retirement, in order to effectively manage and control the LCC and better develop integrated logistics support, it is necessary to analyze and predict it. The unbiased grey markov model(UGMM) was introduced into the LCC prediction in the paper, in order to check model accuracy, the posterior difference method(PDM) was used, also the influence by the number of state intervals in UGMM on the prediction accuracy is analyzed and studied. The result indicate that UGMM can be used to predict the LCC, also have the highest prediction accuracy comparing with unbiased grey model and grey separating model, and in order to ensure the prediction accuracy, the state interval should be divided according to the number of sequence.

Life Cycle Cost Analysis Case Study on Corrosion Remedial Measures for Concrete Structures

2012 ◽  
Author(s):  
Jin How Ho ◽  
Azlan Abd. Rahman
Keyword(s):  
Life Cycle ◽  
Cost Analysis ◽  
Life Cycle Cost ◽  
Net Present Value ◽  
Cost Effective ◽  
Concrete Bridges ◽  
Analysis Tool ◽  
Life Cycle Cost Analysis ◽  
Remedial Measures ◽  
Present Value

Artikel ini membincangkan kajian ringkas berkaitan analisis kos kitaran hayat terhadap langkah-langkah pembaikan pengaratan bagi jambatan dan struktur marin konkrit yang terdedah kepada karbonasi atau serangan natrium klorida daripada air laut atau sumber-sumber lain. Perisian kos kitaran hayat, Bridge LCC 2.0 digunakan untuk menjalankan analisi kitaran hayat untuk tiga kes kajian melibatkan kaedah nilai bersih kini. Keputusan kajian menunjukkan analisis kos kitaran hayat berkeupayaan untuk membantu jurutera dan agensi pengangkutan dalam menilai keputusan penyelenggaraan yang efektif berkaitan dengan masalah pengaratan. Ia boleh digunakan sebagai alat analisis ekonomi kejuruteraan yang membantu mantaksir kos-kos perbezaan dan membuat pilihan terhadap langkah pembaikan pengaratan yang berkesan. Analisis kos kitaran hayat bagi langkah pembaikan dipengaruhi oleh banyak pemboleh ubah seperti kos permulaan, kos penyelenggaraan, tahun kekerapan, dan jangka masa analisis. Amalan terbaik untuk analisis kos kitaran hayat bukan sahaja mengambil kira perbelanjaan oleh agensi, tetapi perlu mempertimbangkan kos-kos oleh pengguna dan analisis sensitiviti di sepanjang jangka hayat sesuatu langkah pembaikan. Kata kunci: Analisis kos kitaran hayat, jambatan konkrit, pengaratan, langkah, pembaikan, pemulihan struktur, keberkesanan kos, kaedah nilai bersih kini (NPV) This paper discusses a short study on life cycle cost analysis (LCCA) on corrosion remedial measures for concrete bridges and marine structures, which are subjected to carbonation or ingress of sodium chloride from sea water and other sources. Life cycle costing software, Bridge LCC 2.0, was used to perform life cycle cost analyses on three case studies, based on net present value method. The analysis of the results showed that LCCA is capable of assisting engineers or transportation agencies to evaluate optimum maintenance decisions in corrosion–related problems. It can be used as an engineering economic analysis tool that helps in qualifying the differential costs and choosing the most cost–effective corrosion remedial measures. Life cycle costs for the remedial measures are influenced by many costing variables such as initial costs, periodic maintenance costs, frequency years and analysis period. The best practice of LCCA should not only consider agency expenditures but also user costs and sensitivity analysis throughout the service life of a remedial measure. Key words: Life cycle analysis, concrete bridges, corrosion, remedial measures, structural rehabilitation, cost-effective, net present value method (NPV)

Estimating submarine groundwater discharges of the Bohai Sea, China using radium, hydrogen and oxygen isotopes and salinity

2020 ◽  
Author(s):  
Hailong Li ◽  
Xiaolang Zhang ◽  
Xuejing Wang ◽  
Kai Xiao ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Steady State ◽  
Mass Balance ◽  
River Water ◽  
Bohai Sea ◽  
Balance Model ◽  
Laizhou Bay ◽  
Bohai Bay ◽  
Fresh Groundwater ◽  
The Bohai Sea ◽  
Submarine Groundwater

&lt;p&gt;With an area of about 77,000 km&lt;sup&gt;2&lt;/sup&gt;, the Bohai Sea includes three bays: Laizhou Bay, Bohai Bay and Liaodong Bay. In this study, &lt;sup&gt;228&lt;/sup&gt;Ra, &amp;#948;D, &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O and salinity data were collected from surface seawater in the entire Bohai Sea, river water, and groundwater along its coastline in August 2017. Based on the spatial distributions of &amp;#948;D, &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O, and salinity in surface water in the entire Bohai Sea and &amp;#948;D-salinity relations, the marine hydrological processes were investigated and the members of river water and groundwater for &amp;#948;D and &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O were determined. The steady-state mass-balance models of &amp;#948;D, &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O and salinity are given and used to estimate submarine fresh groundwater discharges and the flushing times of the entire Bohai Sea and its three bays. Based on the results of the flushing times, the steady-state mass-balance model of &lt;sup&gt;228&lt;/sup&gt;Ra is used to estimate submarine groundwater discharges of the entire Bohai Sea and its three bays.&lt;/p&gt;

scholarly journals Uncertainty estimation in railway track life-cycle cost: a case study from Swedish National Rail Administration

2008 ◽  
Vol 223 (3) ◽  
pp. 285-293 ◽  
Author(s):  
A P Patra ◽  
P Söderholm ◽  
U Kumar
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Cost Effective ◽  
Railway Track ◽  
Statistical Characteristics ◽  
Maintenance Cost ◽  
Cost Models ◽  
Effective Decision ◽  
Effective Decision Support

Life-cycle cost (LCC) is used as a cost-effective decision support for maintenance of railway track infrastructure. However, a fair degree of uncertainty associated with the estimation of LCC is due to the statistical characteristics of reliability and maintainability parameters. This paper presents a methodology for estimation of uncertainty linked with LCC, by a combination of design of experiment and Monte Carlo simulation. The proposed methodology is illustrated by a case study of Banverket (Swedish National Rail Administration). The paper also includes developed maintenance cost models for track.

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