Reliability-Based Design of Transmission Line Structures - Direct Approach Using the Inverse Reliability Method

2002 ◽  
Author(s):  
Hong Li ◽  
Gouri Bhuyan
Keyword(s):  
Transmission Line ◽  
Direct Approach ◽  
Reliability Based Design ◽  
Reliability Method

Barrier Function Method in Reliability Based Design Optimization

2005 ◽  
Vol 297-300 ◽  
pp. 1882-1887
Author(s):  
Tae Hee Lee ◽  
Jung Hun Yoo
Keyword(s):  
Design Optimization ◽  
Barrier Function ◽  
Reliability Index ◽  
Feasible Solution ◽  
Reliability Based Design Optimization ◽  
User Requirement ◽  
Mean Values ◽  
Reliability Based Design ◽  
Design Variables ◽  
Reliability Method

In practical design applications, most design variables such as thickness, diameter and material properties are not deterministic but stochastic numbers that can be represented by their mean values with variances because of various uncertainties. When the uncertainties related with design variables and manufacturing process are considered in engineering design, the specified reliability of the design can be achieved by using the so-called reliability based design optimization. Reliability based design optimization takes into account the uncertainties in the design in order to meet the user requirement of the specified reliability while seeking optimal solution. Reliability based design optimization of a real system becomes now an emerging technique to achieve reliability, robustness and safety of the design. It is, however, well known that reliability based design optimization can often have so multiple local optima that it cannot converge into the specified reliability. To overcome this difficulty, barrier function approach in reliability based design optimization is proposed in this research and feasible solution with specified reliability index is always provided if a feasible solution is available. To illustrate the proposed formulation, reliability based design optimization of a bracket design is performed. Advanced mean value method and first order reliability method are employed for reliability analysis and their optimization results are compared with reliability index approach based on the accuracy and efficiency.

scholarly journals A decoupling algorithm with first-order asymptotic integration for reliability-based design optimization

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879333 ◽  
Author(s):  
Zhiliang Huang ◽  
Tongguang Yang ◽  
Fangyi Li
Keyword(s):  
Design Optimization ◽  
Reliability Analysis ◽  
Optimization Problems ◽  
Asymptotic Integration ◽  
Probabilistic Constraints ◽  
Reliability Based Design Optimization ◽  
First Order Reliability Method ◽  
First Order ◽  
Reliability Based Design ◽  
Reliability Method

Conventional decoupling approaches usually employ first-order reliability method to deal with probabilistic constraints in a reliability-based design optimization problem. In first-order reliability method, constraint functions are transformed into a standard normal space. Extra non-linearity introduced by the non-normal-to-normal transformation may increase the error in reliability analysis and then result in the reliability-based design optimization analysis with insufficient accuracy. In this article, a decoupling approach is proposed to provide an alternative tool for the reliability-based design optimization problems. To improve accuracy, the reliability analysis is performed by first-order asymptotic integration method without any extra non-linearity transformation. To achieve high efficiency, an approximate technique of reliability analysis is given to avoid calculating time-consuming performance function. Two numerical examples and an application of practical laptop structural design are presented to validate the effectiveness of the proposed approach.

A Reliability-Based Design Method Using Simulation Techniques and Efficient Optimization Approach

2004 ◽  
Author(s):  
Tong Zou ◽  
Sankaran Mahadevan ◽  
Akhil Sopory
Keyword(s):  
Computational Cost ◽  
Nonlinear Problems ◽  
Side Impact ◽  
System Level ◽  
Optimization Approach ◽  
Sequential Approach ◽  
Model Based ◽  
Reliability Based Design ◽  
Reliability Method ◽  
Simulation Based

A novel reliability-based design optimization (RBDO) method using simulation-based techniques for reliability assessments and efficient optimization approach is presented in this paper. In RBDO, model-based reliability analysis needs to be performed to calculate the probability of not satisfying a reliability constraint and the gradient of this probability with respect to each design variable. Among model-based methods, the most widely used in RBDO is the first-order reliability method (FORM). However, FORM could be inaccurate for nonlinear problems and is not applicable for system reliability problems. This paper develops an efficient optimization methodology to perform RBDO using simulation-based techniques. By combining analytical and simulation-based reliability methods, accurate probability of failure and sensitivity information is obtained. The use of simulation also enables both component and system-level reliabilities to be included in RBDO formulation. Instead of using a traditional RBDO formulation in which optimization and reliability computations are nested, a sequential approach is developed to greatly reduce the computational cost. The efficiency of the proposed RBDO approach is enhanced by using a multi-modal adaptive importance sampling technique for simulation-based reliability assessment; and by treating the inactive reliability constraints properly in optimization. A vehicle side impact problem is used to demonstrate the capabilities of the proposed method.

Multiobjective Reliability-Based Design of Ship Structures Subjected to Fatigue Damage and Compressive Collapse

2019 ◽  
Author(s):  
Yordan Garbatov ◽  
Ying Cai Huang
Keyword(s):  
Fatigue Damage ◽  
Structural Component ◽  
Pareto Frontier ◽  
Design Solution ◽  
Original Design ◽  
Ship Structures ◽  
Nsga Ii ◽  
Reliability Based Design ◽  
Section Area ◽  
Reliability Method

Abstract This work deals with reliability-based design and optimization of ship structures subjected to stochastic loads and accounting for the local fatigue damage and ultimate global strength. The reliability multi-objective structural optimization is performed in minimizing the structural component net-section area, lateral deflection and fatigue damage. The probability of compressive collapse and fatigue damage of the ship hull is used to define the minimum risk of structural collapse and best design solution. The Pareto frontier solutions calculated by the Non-Dominated Sorting Genetic Algorithm (NSGA-II) is employed in defining the feasible solutions of the design variables. The first order reliability method is employed to estimate the beta reliability index based on the topology of the structural component as a part of the Pareto frontier solutions. Comparing with the original design solution, the optimized section area decreased by 9%.

Reliability‐Based Design of Wood Transmission Line Structures

1983 ◽  
Vol 109 (3) ◽  
pp. 690-704 ◽  
Author(s):  
James R. Goodman ◽  
M. Daniel Vanderbilt ◽  
Marvin E. Criswell
Keyword(s):  
Transmission Line ◽  
Reliability Based Design

Reliability Based Design Optimization of MEMS Considering Pull-In

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Michael Raulli ◽  
Kurt Maute
Keyword(s):  
Design Optimization ◽  
Reliability Based Design Optimization ◽  
Micro Electro Mechanical Systems ◽  
Operational Conditions ◽  
Electrostatically Actuated ◽  
Reliability Based Design ◽  
Reliability Method ◽  
Optimization Methodology ◽  
Novel Devices ◽  
Fully Coupled

The increased use of micro-electro-mechanical systems (MEMS) as key components for actuation and sensing purposes in novel devices and systems emphasizes the need for optimal design methods. Stochastic variations in manufacturing and operational conditions must be considered in order to meet performance goals. This study proposes a reliability based design optimization methodology for the design of geometrically complex electrostatically actuated MEMS. The first order reliability method is used for reliability analysis of fully-coupled electrostatic-mechanical problems. A general methodology for predicting the instability phenomenon of pull-in and incorporating it into an automatic optimization process is proposed and verified with analytical and experimental results. The potential of this methodology is illustrated with the design of an analog micromirror.

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