IWPDF2023

Optimization of Strain Energy in Crack Structure via Fracture Me chanic Based Microdefects using Peridynamic Informed Topology Op timization

P. L. Motlagh ∗

Department of Mechanical Engineering, Gebze Technical University, Gebze, 41400 Kocaeli, Turkey

∗ peyman.lahe@gtu.edu.tr

Keywords: Peridynamic, topology optimizations, micro cracks.

Topology optimizations is vastly used to design light-weighted structures that used in industrial applications. Even tough classical continuum mechanics is implemented commonly to solve topol ogy optimization (TO) problems, but it brings some restrictions to the modeling, analysis, and solution of complex structures with structural discontinuities. On the other hand, peridynamic (PD) theory can overcome these restrictions because of its nonlocal integration nature. Unlike classical continuum mechanics, in this approach, the material does not necessarily require remain ing continuous during the simulations. Thus, it ideally becomes a robust approach for dealing with discontinuities such as cracks, damages, and defects. Recently, a comprehensive comparison is done to compare PD-TO to a finite element method based topology optimization (FEM-TO) to justify its need to be used as a superior method to include defects and thus having more reliable framework [1], furthermore by applying same strategy, its effects are expanded to various studies [2,3]. During additive manufacturing process occurrence of micro crack is inevitable so including micro cracks during design stage helps to prevent unwanted future failure. This paper presents an application of peridynamic based topology optimization (PD-TO) to establish a framework to optimize of micro crack characteristics. Even though there are various studies including defects in PD-TO framework, to the best of Author’s knowledge, there is no study to include fracture-based defect and thus this paper try to investigate the effect of microdefects which may cause due to the various uncertainty during production and by applying their characteristic in exact location by using fracture mechanics based TO, the model is optimized and thus the strain energy can be improved significantly. To this end, the PD-TO model is derived using an in-house MATLAB code. By utilizing the fracture mechanics, best micro cracks orientations and length are optimized. For each structure, strain energy density distributions are compared between different topologies. As a result, importance of predicting unwanted micro cracks during design stage of a macrostructures is presented. References [1] Lahe Motlagh P, Kefal A. Comparative Study of Peridynamics and Finite Element Method for Practical Modeling of Cracks in Topology Optimization. Symmetry. 2021 Aug;13(8):1407. [2] Kendibilir A, Polat MF, Cavus OS, Behrouzyar SK, Motlagh PL, Koc B, et al. Combination of peridynamics and genetic algorithm based topology optimization methods for AM-friendly designs. J Addit Manuf Technol. 2022;2(1):704–704. [3] Motlagh PL, Kendibilir A, Koc B, Kefal A. Peridynamics-informed effect of micro-cracks on topology optimization of lightweight structures. J Addit Manuf Technol. 2021;1(3):610–610.

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