Sampling-Based RBDO of Ship Hull Structures Considering Thermo-Elasto-Plastic Residual Deformation

Abstract

We present a shape optimization method using a sampling-based RBDO method linked with a commercial finite element analysis (FEA) code ANSYS, which is applicable to residual deformation problems of the ship hull structure in welding process. The programming language ANSYS Parametric Design Language (APDL) and shell elements are used for the thermo-elasto-plastic analysis. The shape of the ship hull structure is modeled using the bicubic Ferguson patch and coordinate components of vertices, tangential vectors of boundary curves are selected as design variables. The sensitivity of probabilistic constraint is calculated from the probabilistic sensitivity analysis using the score function and Monte Carlo Simulation (MCS) on the surrogate model constructed by using the Dynamic Kriging (DKG) method. The sequential quadratic programming (SQP) algorithm is used for the optimization. In two numerical examples, the suggested optimization method is applied to practical residual deformation problems in welding ship hull structures, which proves the sampling-based RBDO can be successfully utilized for obtaining a reliable optimum design in highly nonlinear multi-physics problem of thermo-elasto-plasticity.

Reliability based casting process design optimisation

“…The I-RBDO software tool used here can use the results from any simulation package, or combination of packages, to provide the cost function and performance measures in a completely general way. 13,[16][17][18][19][20] For reliability based optimisation, both the multiobjective aspect of the problem through the multiple constraints G j (X) and the uncertainties in the casting manufacturing process and model input variables must be defined. In Fig.…”

“…[13][14][15][16] Using uncertainties in the design process variables, and uncertainties in analytical models and variables used in design processes, the I-RBDO tool determines optimum designs that meet target reliability levels satisfying performance measures and constraints that designers specify. The I-RBDO method has been applied to a range of design problems such as structural design, 13,16 fluid-solid interations, 17 reducing residual deformation in welding, 18 magnetic energy storage systems 19 and multibody system dynamics. 20 The objective of the current study is to investigate use of I-RBDO with casting simulation.…”

Reliability-based energy scheduling of active buildings subject to renewable energy and demand uncertainty

“…However, the main efficient methods of the RBDO algorithms include SORM and FORM. The reader is directed to [27,28] for a comprehensive discussion of these techniques. Based on the suggested framework, Fig.…”

Efficient sampling-based inverse reliability analysis combining Monte Carlo simulation (MCS) and feedforward neural network (FNN)

“…Reliability-based design optimization (RBDO) aims to minimize the objective function of a system while satisfying the probabilistic constraints and has been applied to a wide range of research fields such as structural analysis (Acar and Haftka 2007;Lee et al 2011;Choi et al 2015), vehicle design Grujicic et al 2010;Zhu et al 2015;Lee et al 2019), aerospace design (Frangopol and Maute 2003;Allen and Maute 2004;Bhattacharjee et al 2012;Nam and Mavris 2018), and vehicle system operation (Lee et al 2020). Under uncertainty of design variables Responsible Editor: Pingfeng Wang and parameters, reliability analysis evaluates a probabilistic constraint by predicting the probability of failure of a performance function.…”