Experimental study on crashworthiness and lightweight of cutting-type energy-absorbing structure of magnesium alloy for trains.

Cutting-type structures, because of their desirable mechanical characteristics, high energy absorption capabilities and excellent guiding performance, has been extensively employed in high-speed trains. Its lightweight design and optimization problems are also the hotspot of research directions in present. This paper designed a new-type structure, i.e., magnesium alloy cutting-type energy-absorbing structure (CTEAS), taking into account its excellent properties of high lightweight level and ease of processing demonstrated through AZ31B magnesium alloy tensile mechanical test. Subsequently, experimental study on magnesium alloy CTEAS are conducted by trolley impact tests of train considering different cutting depths and different velocity levels. The results confirmed the outstanding advantages, including high lightweight level and higher absorbed energy properties, and lower demands of knives, compared with the structures with Q345 steel. In addition, the mechanism of knives cracking and melting phenomenon found in the experiment is explored by finite element analytical method. The results show that the temperature difference between the high-temperature surface and the interior during the cutting Q345 steel process is maybe the key influencing factor leading to knives damage. This research provides an effective tool for the design and analysis of excellent performance energy absorbing structure of high-speed trains. • AZ31B magnesium alloy can be used to cutting-type energy-absorbing structures. • Magnesium alloy structure has outstanding advantages in lightweight and higher SEA. • Temperature of the tools during the cutting process of Q345 steel is more than 900 °C. • Temperature of the tools is less than 800 °C when AZ31B magnesium alloy is cut. [ABSTRACT FROM AUTHOR]