Prochenka Paweł, Janiszewski Jacek, Kucewicz Michał
Faculty of Mechatronics, Armament and Aviation, Institute of Armament Technology, Military Univesity of Technology, 2 Gen. S. Kaliskiego Street, 00-908 Warsaw, Poland.
Faculty of Mechanical Engineering, Institute of Mechanics and Applied Computer Science, Military University of Technology, 2 Gen. S. Kaliskiego Street, 00-908 Warsaw, Poland.
Materials (Basel). 2021 May 25;14(11):2808. doi: 10.3390/ma14112808.
The crushing response of a laser-welded square tube absorber made of two commercial steel grades, Docol 1000DP and Docol 1200M, is presented in the paper. Crush experiments are performed at two different loading conditions, namely, quasi-static loading at 0.5 mm/s deformation speed and impact loading at 25-28 m/s. A new approach has been proposed to study the square tube absorber under impact loading using a direct impact Hopkinson (DIH) method. To characterize the mechanical properties of the tested steels, tensile quasi-static and high strain rate testing are also performed with the use of specimens with a 7 mm gauge length. The applied strain rates are 10, 10, and above 10 s. The laser-welded joints are also characterized by microhardness test involving the base material, heat-affected zone, and fusion zone. The crashworthiness of model square tube absorbers is estimated based on the following parameters: absorbed energy, mean force, crushing force efficiency factor, and specific energy absorbed. It has been found that the square tube absorbers made of Docol 1200M steel show a higher potential in mechanical energy absorption capacity than Docol 1000DP absorber. Moreover, crushing tests prove that laser-welded joints in 0.6 mm sheets made of Docol 1000DP and Docol 1200M steels reveal high cracking toughness. In turn, strength testing at different strain rates confirms the higher strain rate sensitivity of Docol 1000DP steel than in the case of Docol 1200M steel as well as an increase in the high ductility properties of both steel grades under the high strain rate loading conditions.
本文介绍了由两种商用钢级Docol 1000DP和Docol 1200M制成的激光焊接方管吸能器的挤压响应。在两种不同的加载条件下进行挤压试验，即0.5 mm/s变形速度下的准静态加载和25 - 28 m/s下的冲击加载。提出了一种使用直接冲击霍普金森（DIH）方法研究冲击加载下方管吸能器的新方法。为了表征测试钢的力学性能，还使用标距长度为7 mm的试样进行了拉伸准静态和高应变率测试。施加的应变率为10、10和高于10 s。激光焊接接头还通过涉及母材、热影响区和熔合区的显微硬度测试进行表征。基于以下参数评估模型方管吸能器的耐撞性：吸收能量、平均力、挤压效率系数和比吸收能量。研究发现，由Docol 1200M钢制成的方管吸能器在机械能吸收能力方面比Docol 1000DP吸能器具有更高的潜力。此外，挤压试验证明，由Docol 1000DP和Docol 1200M钢制成的0.6 mm板材中的激光焊接接头具有高抗裂韧性。反过来，不同应变率下的强度测试证实，Docol 1000DP钢的应变率敏感性高于Docol 1200M钢，并且在高应变率加载条件下两种钢级的高延展性性能均有所提高。
