Evaluation of the axial crashworthiness of thin-walled structures with various and combined cross sections

• Published in: Journal of mechanical science and technology Vol. 32; no. 9; pp. 4271 - 4281
• Main Authors: Davoudi, Mohammadmahdi, Kim, Cheol
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society of Mechanical Engineers 01.09.2018; Springer Nature B.V; 대한기계학회
• Subjects: Control; Crashworthiness; Cross-sections; Dynamical Systems; Engineering; Exact solutions; Impact strength; Industrial and Production Engineering; Mechanical Engineering; Numerical analysis; Thin wall structures; Vibration; 기계공학; Thin-walled structures; Crashworthiness; Combined cross sections
• ISSN: 1738-494X; 1976-3824
• DOI: 10.1007/s12206-018-0825-1

This paper is categorized in three consequent steps to increase the crashworthiness of thin-walled structures subject to dynamic compression in the axial direction. In the first step, a numerical analysis obtains the advantage of each tube with a different cross-section to extract the most crashworthy thin-walled structure. Second, an appropriate combined cross section is designed, and it demonstrates a significant improvement in the crashworthiness ( EA , F mean , F max , CFE and CS ) of the structure. The designed structure is a combination of a square crash box to work at the first time steps of a collision to dramatically decrease F max . For the rest of steps, a circular crosssection is used to maximize EA and F mean , and decrease CS . This idea helps to control and enhance the crashworthiness of the structure. Thirdly, a thorough research is done to obtain the optimum length for each one of combined sections. The CFE of the structure increased by 15 % compared to the square section, and 78 % compared to the circular section in spite of decreasing CS . The numerical result of the square cross tube is compared with the existing analytical solution as a sample. Furthermore, numerical results for other cross sections show similar trends to the literature. These two facts indicate the validity of the obtained numerical results.