A Single-Loop Approach for Time-Variant Reliability-Based Design Optimization

Zhiliang Huang

doi:10.1109/TR.2017.2703593

2017-09-01

黄志良 (Zhiliang Huang) *

Chao Jiang (Chao Jiang)

DOI：10.1109/TR.2017.2703593

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摘要

En 中文

In the process of long-term use, the uncertainty of an engineering structure often presents time-variant or dynamic characteristics due to the influence of stochastic loads and material performance degradations. In such a situation, the structural design optimization will involve an important problem of time-variant reliability-based design optimization (TRBDO). Performing TRBDO involves a nested optimization, which will lead to extremely low computational efficiency. In this paper, a single-loop approach (SLA) is proposed to convert the nested optimization in TRBDO into a sequence iterative process composed of the time-variant reliability analysis (TRA), constraint discretization, and design optimization. In each iteration step, the TRA method based on stochastic process discretization is first used to calculate the time-variant reliability of constraints; second, through introducing the concept of the target reliability index of discretized time period and proposing the corresponding algorithm, each time-variant constraint is discretized into a series of time-invariant constraints to formulate a conventional reliability-based design optimization problem. The approach exhibits a good comprehensive performance in terms of efficiency and convergence. The validity and practicality of the SLA are validated by two numerical examples and a design problem for the chassis of a self-balancing vehicle.

Keyword:

Performance degradation

single-loop approach (SLA)

stochastic process

time-variant reliability analysis (TRA)

time-variant reliability-based design optimization (RBDO)