Crashworthiness optimization of bionic bumper structure under low-speed impact Tao Xu, Nian Liu, Yuan Tian, Tianshuang Xu, Tianyi Zhang, Zhenglei Yu and Yiwen Li MATEC Web Conf., 189 (2018) 07001 Published online: 10 August 2018 DOI: 10.1051/matecconf/201818907001