An improved optimization method is proposed which combines the particle swarm (PSO) algorithm with dimension reduction kriging surrogate model (DK), namely PSO + DK. In this method, a dynamically constructed and updated between lower dimensional principal components response, instead of high-dimensional design variables response as in traditional methods. The key point DK that analysis (PCA) integrated active learning (AK). Since PCA can reduce effectively, makes construction possible for...

In engineering applications, computer experiments such as finite element analysis and computational fluid dynamics are often used to model analyse structural behaviours. this article, a surrogate-based particle swarm optimization algorithm is proposed for solving problems with expensive black box functions. An approximate problem in which the functions replaced by hybrid surrogate models efficiently solved search adjust global optimum position during iterative process. Since presented method...

The present work aims to develop a method for reliability-based optimum design of composite structures. A procedure combining particle swarm optimization (PSO) and finite element analysis (FEA) has been proposed. Numerical examples the reliability (RDO) laminate cylindrical shell are worked out demonstrate effectiveness method. Then pressure vessels is studied. advantages necessity RDO over conventional equi-strength addressed. Examples show that proposed good stability efficient in dealing...

In practical applications, there may exist a disparity between real values and optimal results due to uncertainties. This kind of cause violations some probabilistic constraints in reliability based design optimization (RBDO) problem. It is important ensure that the at optimum RBDO problem are insensitive variations variables. this paper, we propose novel concept procedure for robust context random uncertainty epistemic uncertainty. The variables first described by an info gap model, then...

This paper develops a method for the time-dependent reliability analysis of deteriorating structures using phase-type (PH) distributions. The model consists two aspects: progressive deterioration posed by aging effects, and shock caused random shocks. Evaluating distribution sum variables is tough work in model. For simplified problems that follow specific distributions with convolutions being derived analytically, it effective to utilize semianalytical methods analysis. other general (the...

Performance and reliability of structures will deteriorate with time as a result the effects various loads environment. This paper aims to develop time-dependent model deteriorating that considers both aging random shocks. First, is proposed in which effect modeled gamma process while shock described by Poisson process. The structural components then evaluated based on model. To incorporate uncertainties, Bayesian inference methods are further integrated update uncertain parameters using...

The unexpected outbreak of COVID-19 triggered fear and anxiety in the general population. Exercise was one most widely promoted methods to improve body function when socially restricted. This study aims examine role exercise relieving stressful mental health outcomes (anxiety depressive symptoms) during pandemic explore underlying mechanism from perspective hope, using a combination goal-directed planning (pathways) motivation (agency). A cross-sectional online survey recruiting 2390 Chinese...

Filament-wound composite pressure vessels, owing to the advantages of their high specific strength, modulus and fatigue resistance, as well excellent design performance, have been widely used in energy engineering, chemical industry other fields. A filament-wound vessel generally consists two parts, a cylindrical drum part dome parts. In part, filament winding angle layer thickness can be easily determined due regular shape. however, both vary along meridian line. Performance which strongly...

A new approach to the particle swarm optimization (PSO) is proposed for solution of non-linear problems with constraints, and applied reliability-based optimum design laminated composites. Special mutation-interference operators are introduced increase variety improve convergence performance algorithm. The composites modelled solved using improved PSO. maximization structural reliability minimization total weight laminates analysed. stacking sequence implemented in PSO by a special coding...

Reliability analysis methods such as active learning Kriging surrogate model combined with simulation-based have been paid much attention in recent years. These techniques can reduce the computational cost to a certain extent. However, burden may still be heavy for complex engineering problems. To address these issues, Kriging-based important region sampling method is proposed efficient reliability analysis. The new an improvement on original combining and Monte Carlo simulation (AK-MCS),...

Compared with a constant stiffness (CS) composite structure of traditional straight fiber path, variable (VS) curvilinear path has broader design space. Taking the performance CS cylinder as baseline, two curved formats VS cylinders are investigated. One is that angle varies in circumferential direction (i.e., variation, VS-C), other both and axial directions variation,VS-CA). Non-uniform rational B-spline curve/surface used to define continuously varying orientation angle, making come true....