Target structural reliability in life cycle consideration

For the development of the System Based Code, which was proposed by Asada and intends to optimize structural design of nuclear components by enabling margin exchange between various technical options, a tool for life cycle structural reliability evaluation method is necessary. For this purpose, the authors are developing a material strength and structural reliability evaluation system MSS-REAL. The system is primarily for fast breeder reactors but its methodologies can also be applied to the other types of reactors. This paper summarizes the features of the MSS-REAL system with examples and also describes a future development plan.

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Analysis of the Seismic Performance of Isolated Buildings according to Life-Cycle Cost

Computational Intelligence and Neuroscience ◽

10.1155/2015/495042 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Yu Dang ◽

Jian-ping Han ◽

Yong-tao Li

Keyword(s):

Life Cycle ◽

Seismic Performance ◽

Life Cycle Cost ◽

Structural Reliability ◽

Expected Loss ◽

Structural Capacity ◽

Fixed Base ◽

Hospital Building ◽

Major Factors ◽

Design Construction

This paper proposes an indicator of seismic performance based on life-cycle cost of a building. It is expressed as a ratio of lifetime damage loss to life-cycle cost and determines the seismic performance of isolated buildings. Major factors are considered, including uncertainty in hazard demand and structural capacity, initial costs, and expected loss during earthquakes. Thus, a high indicator value indicates poor building seismic performance. Moreover, random vibration analysis is conducted to measure structural reliability and evaluate the expected loss and life-cycle cost of isolated buildings. The expected loss of an actual, seven-story isolated hospital building is only 37% of that of a fixed-base building. Furthermore, the indicator of the structural seismic performance of the isolated building is much lower in value than that of the structural seismic performance of the fixed-base building. Therefore, isolated buildings are safer and less risky than fixed-base buildings. The indicator based on life-cycle cost assists owners and engineers in making investment decisions in consideration of structural design, construction, and expected loss. It also helps optimize the balance between building reliability and building investment.

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Simulation-Based Life-Cycle Structural Reliability of Deteriorating RC Bridges Using Bayesian Updating

Lecture Notes in Civil Engineering - Proceedings of the 1st Conference of the European Association on Quality Control of Bridges and Structures ◽

10.1007/978-3-030-91877-4_156 ◽

2021 ◽

pp. 1368-1376

Author(s):

Mehmet F. Yilmaz ◽

Mattia Anghileri ◽

Luca Capacci ◽

Fabio Biondini

Keyword(s):

Life Cycle ◽

Structural Reliability ◽

Bayesian Updating ◽

Simulation Based

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Optimization of Design Parameters for Materials Consumption for Reinforcing Metal Framework of Industrial Buildings

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.875.122 ◽

2018 ◽

Vol 875 ◽

pp. 122-127 ◽

Cited By ~ 2

Author(s):

Tatyana Zolina ◽

Pavel Sadchikov

Keyword(s):

Life Cycle ◽

Mathematical Models ◽

Optimum Design ◽

Structural Reliability ◽

Steel Structures ◽

Design Methods ◽

Design Parameters ◽

Seismic Resistance ◽

Economic Costs ◽

Industrial Buildings

This study investigated optimum design methods for frame buildings with focus on minimization of economic costs. The methods discussed are intended to provide sufficient reserves for reliability of load-bearing steel structures. The analyzed mathematical models enable to assess seismic resistance of a structure and implement optimum design methods according to the selected key criterion. The available mathematical models assessing economic efficiency of metalwork reinforcement need further development. The model based on the principle of balanced risk is considered as the most appropriate for the study of structural reliability for industrial buildings. This model allows to assess the expected damage as compared with the initial spending on seismic protection. The focus is on setting and implementation of the task whose limiting condition provides equality between expenditures for reinforcement of damaged steel structures and those for damage prevention activities. Minimum of economic costs for construction or reconstruction of a structure is taken as the optimality criterion. This takes into account accumulation of damages within the standard life cycle and changes in stiffness of materials. Assessment of damage risk is based on the life cycle of a structure, its seismic resistance class and spending on damage repair. The study suggests a number of structural solutions that enable to reduce deformation of steel parts of the frame.

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Reliability Assessment of Marine Drilling Risers With Correlated Random Variables

Volume 3: Structures, Safety and Reliability ◽

10.1115/omae2016-54434 ◽

2016 ◽

Author(s):

Piyali Sengupta ◽

Ying Min Low ◽

Xiaodong Zhang ◽

Peter Francis Bernad Adaikalaraj ◽

Chan Ghee Koh

Keyword(s):

Life Cycle ◽

Computational Model ◽

Reliability Analysis ◽

Deep Water ◽

Environmental Conditions ◽

Life Cycle Cost ◽

Structural Reliability ◽

Random Variables ◽

Density Functions ◽

Total Life

Marine drilling risers are integral parts of the deep water offshore oil and gas industry. They are required to be designed for safe operations during their service lives with appropriate degree of reliability. With limited experience present in ultra-deep water, drilling risers are subjected to a range of uncertainties arising from untested environmental conditions. However, the current industry practice is limited to deterministic design of drilling risers which cannot account for uncertainties present in real life scenario. Under uncertain environmental conditions, deterministic methods may lead to undesired consequences, i.e. over conservative or unsafe design and misguided estimates of operability and down time of ultra-deep water drilling risers affecting the total life cycle cost. Thus, structural reliability analysis is particularly useful for prediction of the probabilities of downtime and disconnection of drilling risers incorporating the environmental uncertainties. In addition, structural reliability analysis can be used to reduce the total life cycle cost of ultra-deep water drilling risers. In reliability analysis, many studies use uncorrelated random variables to represent uncertainties for simplification. Nevertheless, uncertainties in environmental conditions may be strongly correlated (for example wind and wave loads). If the correlation is not accounted for, it may lead to erroneous probability estimates. Thus, a joint environmental model is proposed in this paper using the conditional modeling approach where a joint density function is defined in terms of a marginal distribution and a series of conditional density functions. The joint density functions of environmental conditions are constructed in the current study using the recorded metocean data for Gulf of Mexico available from National Oceanic and Atmospheric Administration (NOAA) website. Then a computational model of connected ultra-deep water drilling riser system is constructed in ORCAFLEX to conduct time domain dynamic analysis. Thereafter, the correlated random variables in combination with the drilling riser computational model are utilized for conducting Monte Carlo Simulation (MCS) to evaluate the probabilities of downtime and disconnection. MCS is a widely accepted and robust approach and generally used as a benchmark to verify the accuracy of other reliability methods. But, in presence of large number of random variables representing environmental uncertainties, MCS is computationally demanding especially for the large number of simulations required to estimate small failure probabilities associated with extreme values. To this end, probability density functions of drilling riser responses are evaluated using Shifted Generalized Lognormal Distribution (SGLD) and Generalized Extreme-Value (GEV) Distribution both of which show similar accuracy (compared to MCS results) at a fraction of computing time (around 1/500 times).

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Ultrastructural analysis of “Sensory” surface nerve endings and “putative” neurotransmitter sites in Schistosoma mansoni Miracidia

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156791 ◽

1989 ◽

Vol 47 ◽

pp. 962-963

Author(s):

Betty Ruth Jones ◽

Steve Chi-Tang Pan

Keyword(s):

Nervous System ◽

Life Cycle ◽

Schistosoma Mansoni ◽

Snail Host ◽

Complex Life Cycle ◽

Rational Approach ◽

Effective Control ◽

The Social ◽

Social And Economic Development ◽

Basic Biology

INTRODUCTION: Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is worldwide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease and thus the number of infections are increasing.Our knowledge of the basic biology of the parasites causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes. The future of the entire life cycle depends on the capacity and ability of this organism to locate and enter a suitable snail host for further development, Little is known about the nervous system of the miracidium of Schistosoma mansoni and of other trematodes. Studies indicate that miracidia contain a well developed and complex nervous system that may aid the larvae in locating and entering a susceptible snail host (Wilson, 1970; Brooker, 1972; Chernin, 1974; Pan, 1980; Mehlhorn, 1988; and Jones, 1987-1988).

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A freeze-fracture-etched study of the physarum polycephalum plasma membrane during early formation of the macroplasmodial stage

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100147570 ◽

1993 ◽

Vol 51 ◽

pp. 346-347

Author(s):

Randolph W. Taylor ◽

Henrie Treadwell

Keyword(s):

Plasma Membrane ◽

Life Cycle ◽

Growth Phase ◽

Filter Paper ◽

Physarum Polycephalum ◽

Freeze Fracture ◽

Petri Dish ◽

Wire Screen ◽

Wide Mouth ◽

Sterile Filter

The plasma membrane of the Slime Mold, Physarum polycephalum, process unique morphological distinctions at different stages of the life cycle. Investigations of the plasma membrane of P. polycephalum, particularly, the arrangements of the intramembranous particles has provided useful information concerning possible changes occurring in higher organisms. In this report Freeze-fracture-etched techniques were used to investigate 3 hours post-fusion of the macroplasmodia stage of the P. polycephalum plasma membrane.Microplasmodia of Physarum polycephalum (M3C), axenically maintained, were collected in mid-expotential growth phase by centrifugation. Aliquots of microplasmodia were spread in 3 cm circles with a wide mouth pipette onto sterile filter paper which was supported on a wire screen contained in a petri dish. The cells were starved for 2 hrs at 24°C. After starvation, the cells were feed semidefined medium supplemented with hemin and incubated at 24°C. Three hours after incubation, samples were collected randomly from the petri plates, placed in plancettes and frozen with a propane-nitrogen jet freezer.

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