9. Strikers of nonaxisymmetric optimal shape

The numerical simulation of the optimal design of gravity dams is computationally expensive. Therefore, a new optimization procedure is presented in this study to reduce the computational cost for determining the optimal shape of a gravity dam. Optimization was performed using a combination of the genetic algorithm (GA) and an updated Kriging surrogate model (UKSM). First, a Kriging surrogate model (KSM) was constructed with a small sample set. Second, the minimizing the predictor strategy was used to add samples in the region of interest to update the KSM in each updating cycle until the optimization process converged. Third, an existing gravity dam was used to demonstrate the effectiveness of the GA–UKSM. The solution obtained with the GA–UKSM was compared with that obtained using the GA–KSM. The results revealed that the GA–UKSM required only 7.53% of the total number of numerical simulations required by the GA–KSM to achieve similar optimization results. Thus, the GA–UKSM can significantly improve the computational efficiency. The method adopted in this study can be used as a reference for the optimization of the design of gravity dams.

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Compactness of 𝑀-uniform domains and optimal thermal insulation problems

Advances in Calculus of Variations ◽

10.1515/acv-2020-0088 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Hengrong Du ◽

Qinfeng Li ◽

Changyou Wang

Keyword(s):

Thermal Insulation ◽

Heat Insulation ◽

Optimization Problems ◽

Optimal Shape ◽

Optimal Heat ◽

Optimal Shapes ◽

Stable Solutions ◽

Uniform Domains

Abstract In this paper, we will consider an optimal shape problem of heat insulation introduced by [D. Bucur, G. Buttazzo and C. Nitsch, Two optimization problems in thermal insulation, Notices Amer. Math. Soc. 64 (2017), 8, 830–835]. We will establish the existence of optimal shapes in the class of 𝑀-uniform domains. We will also show that balls are stable solutions of the optimal heat insulation problem.

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The Study on Crashworthiness Performance of Thin-Walled Structures and the Effect of Welding Performance on it

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.63-64.655 ◽

2011 ◽

Vol 63-64 ◽

pp. 655-658

Author(s):

Qi Hao ◽

Sheng Jun Wu

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Welded Joints ◽

Impact Force ◽

Deformation Energy ◽

Optimal Shape ◽

Explicit Finite Element Method ◽

Explicit Finite Element ◽

Thin Walled Structures ◽

Thin Walled

Explicit finite element method is adopted to simulate the crashworthiness performance of four types of typical thin—walled structures used in vehicle by software LS-DYNA. The structures with the same material、area and length are crash by a rigid body with 40km/h in10ms, The crash processes and crashworthiness characters are analyzed by a series crash parameters: deformation energy with unit displacement, impact force and deceleration to look for the optimal shape with crashworthiness. With comparing, the double caps section has ascendant performance than the others. The simulating methods of welded-joints are discussed to analysis their effects on crashworthiness simulation.

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