Analysis of crashworthiness of the dimpled thin-walled structures

Liang, Ce (2018) Analysis of crashworthiness of the dimpled thin-walled structures. Doctoral thesis (PhD), University of Sussex.

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Abstract

Thin-walled structures are often used as kinetic energy absorbers in vehicular systems and infrastructure designs. In such applications, high specific energy absorption is usually desirable, because it is beneficial for weight reduction. The dimpling cold-roll metal forming process introduces dimpled geometry and increases the strength of sheet metal. This thesis aims to investigate the energy absorption characteristics of the dimpled thin-walled structures.
A finite element (FE) modelling analysis was performed using ANSYS Explicit Dynamics solver, to predict the response of dimpled structures to dynamic and quasi-static loads. A series of experimental tests were conducted and the FE method was validated through comparing the numerical and experimental results.
To understand the response of the dimpled structural components to axial crushing loads, numerical simulations were performed. A parametric study on a key cold-roll forming parameter “forming depth” was carried out to evaluate its effects on the dimpled geometry and material properties. Through the parametric study, manufacturing parameters for the cold-roll forming process were suggested to improve yield strength and energy absorption performance of dimpled steel components. It was shown that the specific energy absorption can be increased by up to 16% after optimizing the forming depth.
To take the most advantage of the dimpled geometry, multi-layer dimpled thin-walled columns were analysed. The interlocking mechanism of dimpled plates were investigated and an empirical model was proposed to describe the interaction between dimpled plates. It was shown that a considerable amount of energy can be absorbed through the interaction between dimpled walls.
The behaviour of dimpled columns under lateral impact loads was also investigated. It was revealed that the introduced dimpled geometry contributes to reducing the peak impact force without sacrificing the energy absorption capacity. However, this is only valid when at least one end of the dimpled thin-walled column is fully restrained.

Item Type: Thesis (Doctoral)
Schools and Departments: School of Engineering and Informatics > Informatics
Subjects: T Technology > TA Engineering (General). Civil engineering (General) > TA0329 Engineering mathematics. Engineering analysis > TA0347.A-Z Other specific mathematical aids in the solution of engineering problems, A-Z > TA0347.F5 Finite element method
Depositing User: Library Cataloguing
Date Deposited: 20 Sep 2018 08:26
Last Modified: 20 Sep 2018 08:26
URI: http://sro.sussex.ac.uk/id/eprint/78870

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