Fatigue reliability based optimal design of planar compliant micropositioning stages

2015 ◽  
Vol 86 (10) ◽  
pp. 105117 ◽  
Author(s):  
Qiliang Wang ◽  
Xianmin Zhang
Keyword(s):  
Optimal Design ◽  
Fatigue Reliability ◽  
Micropositioning Stages

A Simplified Method for Quantitative Reliability and Integrity Analysis of Steel Catenary Risers

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Mir Emad Mousavi ◽  
Zaqie Reza ◽  
Sanjeev Upadhye ◽  
Vishnu Vijayaraghavan ◽  
Kevin Haverty
Keyword(s):  
Optimal Design ◽  
Environmental Conditions ◽  
Limit State ◽  
Fatigue Reliability ◽  
Strength Limit ◽  
Strength Failure ◽  
Annual Probability ◽  
Steel Catenary Risers ◽  
Integrity Analysis ◽  
Scr System

Quantitative reliability and integrity analysis of steel catenary risers (SCRs) can provide important information about their safety and toward their cost-effective and optimal design. SCRs are one of the commonly used riser systems in offshore production stations. The consequence of an SCR failure is significant; however, the overall safety of the riser is typically not quantified. Especially, because of the uncertainties associated with environmental conditions and structural capacities, quantitative reliability methods can take advantage of available data and developments in computing technology to provide a strong basis for their reliable engineering decision making. This paper presents a simplified approach for assessing the strength and fatigue reliability of SCRs, accounting for the uncertainties with their yield strength and fatigue capacities as well as the environmental conditions. Moreover, the integrity-based optimal design of riser strength limit state for a target annual probability of failure is discussed. The fatigue reliability of the SCR system is also assessed in component and system levels. The proposed method is then applied to a typical SCR attached to a semisubmersible vessel under Gulf of Mexico (GOM) conditions. Results of dynamic (time-domain) analyses under various environmental conditions are used to quantify the SCR safety and integrity and to optimize its design for a target annual probability of strength failure. By estimating the riser system probability of strength and fatigue failure in its lifetime, the strength and fatigue integrity indices, and the optimality factors of the riser sections for the strength limit state, suggestions are provided to improve the riser design. For example, it was found that considering the two main limit states of strength and fatigue failure of the SCR system, a strength failure at the taper stress joint (TSJ) is the likely mode of failure in this riser system, which has a probability of 0.0035 in its 25 year lifetime.

A Simplified Method for Quantitative Reliability and Integrity Analysis of SCRs

2014 ◽  
Author(s):  
Mir Emad Mousavi ◽  
Zaqie Reza ◽  
Sanjeev Upadhye ◽  
Vishnu Vijayaraghavan ◽  
Kevin Haverty
Keyword(s):  
Optimal Design ◽  
Fatigue Failure ◽  
Environmental Conditions ◽  
Limit State ◽  
Fatigue Reliability ◽  
Strength Limit ◽  
Strength Failure ◽  
Annual Probability ◽  
Integrity Analysis ◽  
Scr System

Quantitative reliability and integrity analysis of Steel Catenary Risers (SCR) can provide important information about their safety and towards their cost-effective and optimal design. SCRs are one of the commonly used riser systems in offshore production stations. The consequence of a SCR failure is significant; however, the overall safety of the riser is typically not quantified. Especially, because of the uncertainties associated with environmental conditions and structural capacities, quantitative reliability methods can take advantage of available data and developments in computing technology to provide a strong basis for their reliable engineering decision making. This paper presents a simplified approach for assessing the strength and fatigue reliability of SCRs, accounting for the uncertainties with their yield-strength and fatigue capacities as well as the environmental conditions. Moreover, the integrity-based optimal design of riser strength limit state for a target annual probability of failure is discussed. The fatigue reliability of the SCR system is also assessed in component and system levels. The proposed method is then applied to a typical SCR attached to a semi-submersible vessel under Gulf of Mexico conditions. Results of dynamic (time-domain) analyses under various environmental conditions are used to quantify the SCR safety and integrity and to optimize its design for a target annual probability of strength failure. By estimating the riser system probability of strength and fatigue failure in its lifetime, the strength and fatigue integrity indices, and the optimality factors of the riser sections for the strength limit state, suggestions are provided to improve the riser design. For example, it was found that considering the two main limit states of strength and fatigue failure of the SCR system, a strength failure at the taper stress joint is the likely mode of failure in this riser system, which has a probability of 0.0035 in its 25 years lifetime.

Optimal Design of Cylindrical Helical Torsional Spring Including Fatigue Reliability

2013 ◽  
Vol 395-396 ◽  
pp. 862-865
Author(s):  
Shi Jian Zhao ◽  
Wei Min Cui ◽  
Wei Tian
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Optimal Design ◽  
New Method ◽  
Fatigue Reliability ◽  
Torsion Spring ◽  
New Methods ◽  
Traditional Design ◽  
Torsional Spring ◽  
Test Points

To get a way of calculating the reliability of fatigue life of torsion spring, the paper discussed the optimal design of fatigue reliability for cylindrical helical torsional spring with Monte-Carlo method, and tried to build a new method to analyze the fatigue reliability of cylindrical helical torsional spring. The new method could test different values of parameters of a spring, and it could calculate the fatigue reliability of the spring in every parameter value with about 100 thousand test points with Monte-Carlo method, which can be set to get a better result, and it gave the comparison and selection to designers finally. The method was run with the software-MATLAB. The paper gave an example at last, and it compared the new methods results with ones of traditional design and discussed the differences.

Crack divergence phenomena in tempered glass

2020 ◽  
Vol 13 (3) ◽  
pp. 115-129
Author(s):  
Shin’ichi Aratani
Keyword(s):  
Optimal Design ◽  
High Speed ◽  
Glass Plate ◽  
Acute Angle ◽  
Divergence Angle ◽  
High Speed Photography ◽  
Tempered Glass ◽  
Thick Glass

High speed photography using the Cranz-Schardin camera was performed to study the crack divergence and divergence angle in thermally tempered glass. A tempered 3.5 mm thick glass plate was used as a specimen. It was shown that two types of bifurcation and branching existed as the crack divergence. The divergence angle was smaller than the value calculated from the principle of optimal design and showed an acute angle.

G Optimal Design in Non linear Models to Increase Silicon Oxide Purity Levels and Electrical Conductivity

2018 ◽  
pp. 150-155
Author(s):  
Muklas Rivai
Keyword(s):  
Electrical Conductivity ◽  
Optimal Design ◽  
Linear Models ◽  
Silicon Oxide ◽  
Information Matrix ◽  
Relevant Information ◽  
Non Linear

Optimal design is a design which required in determining the points of variable factors that would be attempted to optimize the relevant information so that fulfilled the desired criteria. The optimal fulfillment criteria based on the information matrix of the selected model.

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