Comparison of functionally-graded structures under multiple loading angles

• Published in: Thin-walled structures Vol. 94; pp. 334 - 347
• Main Authors: Li, Guangyao, Zhang, Zheshuo, Sun, Guangyong, Huang, Xiaodong, Li, Qing
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2015
• Subjects: Circular tubes; Crashworthiness; Equivalence; Foams; Functionally graded thickness; Functionally gradient materials; Impact strength; Mathematical analysis; Oblique load; Optimization; Tubes; Foams; Functionally graded thickness; Oblique load; Optimization; Crashworthiness
• ISSN: 0263-8231; 1879-3223
• DOI: 10.1016/j.tws.2015.04.030

This paper provides a comparative study on the crashworthiness of different functionally-graded thin-wall tubes under multiple loading angles, which include hollow uniform thickness (H-UT), hollow functionally graded thickness (H-FGT), foam-filled uniform thickness (F-UT) and foam-filled functionally graded thickness (F-FGT) configurations. First, finite element analyses of these differently graded circular tubes reveal that the F-FGT tube has the best crashworthiness under multiple loading angles. Second, parametric study on the F-FGT tube indicates that the thickness gradient and variation range significantly influence its crashworthiness. Third, the Non-dominated Sorting Genetic Algorithm (NSGA-II) is used to optimize the F-FGT tube, in which the optimal thickness variation is sought for maximizing specific energy absorption (SEA) and minimizing initial peak force (IPF) under multiple loading angles. The optimized F-FGT tube exhibits better crashworthiness than other three equivalent tube configurations, indicating that the F-FGT tube can be a potential energy absorber when oblique impact loading is inevitable. •Crashworthiness of thin-walled structures with functionally graded wall thickness under multiple load cases.•Multiobjective optimization for multiple load cases.•Design of functionally-graded wall thickness for energy absorber subject to oblique loads.