Li Kangjie, Feng Yixiong, Gao Yicong, Zheng Hao, Qiu Hao
State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou 310027, China.
Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province, Zhejiang University, Hangzhou 310027, China.
Materials (Basel). 2020 Feb 2;13(3):666. doi: 10.3390/ma13030666.
Aluminum alloy thin-walled structures have been well used in applications of energy absorption. In the present work, a bioinspired design strategy for aluminum alloy thin-walled structures is proposed to improve the performance of out-of-plane crashworthiness by altering the material distribution. According to the proposed strategy, a novel fractal thin-walled triangle column (FTTC) is designed, which is composed by iteratively applying the affine transformation of a base triangle up to 2nd-order. The finite element model is established to investigate the out-of-plane crashworthiness of FTTC and validated by experiment results. The numerical analysis of the crashworthiness of FTTC with different fractal orders (0th, 1st and 2nd) are performed, and the results show that 1st- and 2nd-order FTTC enhance the energy absorption of structures and crush force efficiency. In particular, 2nd-order FTTC has better energy absorption ability due to the optimal distribution of materials, which are efficiently organized by the proposed bioinspired design strategy. In addition, a parameter study is performed to investigate the effect of FTTC geometric details on the crushing procedure. The collapse mode shows that it tends to change from unstable to stable with the increase in thickness and side length and the decrease in height. Moreover, a positive relevant relationship is identified between the thickness and the crashworthiness for FTTC.
铝合金薄壁结构在能量吸收应用中已得到广泛应用。在本研究中，提出了一种用于铝合金薄壁结构的仿生设计策略，通过改变材料分布来提高面外抗撞性。根据该策略，设计了一种新型分形薄壁三角柱（FTTC），它由对一个基础三角形进行高达二阶的仿射变换迭代应用而成。建立了有限元模型来研究FTTC的面外抗撞性，并通过实验结果进行了验证。对不同分形阶（0阶、1阶和2阶）的FTTC的抗撞性进行了数值分析，结果表明一阶和二阶FTTC提高了结构的能量吸收和挤压力效率。特别是，二阶FTTC由于材料的最优分布而具有更好的能量吸收能力，这些材料是通过所提出的仿生设计策略有效组织起来的。此外，还进行了参数研究，以研究FTTC几何细节对挤压过程的影响。坍塌模式表明，随着厚度和边长的增加以及高度的减小，它倾向于从不稳定变为稳定。此外，还确定了FTTC的厚度与抗撞性之间存在正相关关系。
