Comparisons between DP780 and DP980 Duplex Steel Beams with Hat-Section under Axial Impact
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摘要: 作为汽车及航空工业中主要承载和碰撞吸能部件,帽型薄壁梁可通过自身结构塑性变形实现被动吸能。因此,研究帽型薄壁梁结构在冲击载荷作用下的变形模式和吸能特性对其被动安全设计具有重要的意义。分别对DP980和DP780双相钢帽型薄壁梁结构开展了落锤轴向冲击实验,并对其变形位移、峰值载荷、变形模态和能量吸收能力进行分析。研究结果表明:无论是DP980还是DP780帽型梁试件,在受到冲击载荷作用时,均从试件上部发生塑性屈曲变形并形成褶皱,其下部则无明显变形;DP980帽型梁冲击变形更小,残余高度更高,宜作为抗冲击变形防护结构;DP780帽型梁最终屈曲变形产生褶皱更多,冲击载荷作用时间增加,峰值载荷更低,宜作为抗冲击载荷防护结构。综合考虑吸能效果,DP980帽型梁的能量吸收能力与DP780帽型梁相近,研究结果为冲击防护结构的选材提供依据。Abstract: As the main energy absorbing component of bearing and collision in the automobile and aviation industry, the hat-section beam structure absorbs energy through plastic deformation of its own structure, which is the main criteria for previous safety design. Therefore, it is of great significance to study the deformation characteristics and energy absorption characteristics of the hat-section and thin-walled beam structure under impact load. In this paper, the axial dropping impact tests of DP780 and DP980 duplex steel with hat-section thin-walled beam structures are carried out with a dropping hammer designed by ourselves, and the maximum displacement, peak load, deformation modes and energy absorption are obtained. The results show that the plastic buckling of the upper part of the specimen is formed and the deformation of the lower part is unobvious for DP980 and DP780 hat-section beams under impact loads. The DP980 hat-section beam has less impact deformation and higher residual height, which can be used as the protection structure of anti-impact deformation. The DP780 hat-section beam has more wrinkles produced by final buckling deformation, and its impact time increases and the peak load is much lower, which can be used as the protection structure of anti-impact load. The energy absorption capacity of the DP980 hat-section beam is similar to that of the DP780 hat-section beam. The results provide the basis for the selection of anti-impact performance with thin-walled structure.
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Key words:
- hat-section beam /
- duplex steel /
- axial impact /
- deformation modes /
- energy absorption capacity
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表 1 实验变形参数
Table 1. Deformation parameters from experiments
Specimen h/mm t/ms Specimen h/mm t/ms A1 200 48.2 B1 147 58.7 A2 198 48.6 B2 150 59.7 A3 198 48.8 B3 150 59.2 A4 198 48.4 B4 151 59.6 A5 193 49.3 B5 140 63.6 A6 192 49.9 B6 151 60.1 表 2 试件冲击实验结果
Table 2. Impact test results of the specimens
Specimen EA/kJ Fmax/kN Favg/kN η Specimen EA/kJ Fmax/kN Favg/kN η A1 16.9 327.64 84.50 0.2579 B1 17.5 269.27 69.16 0.2568 A3 17.1 315.52 84.65 0.2682 B2 17.6 268.58 70.40 0.2560 A4 17.1 301.67 84.75 0.2809 B4 17.7 271.19 71.08 0.2621 A5 17.2 312.59 83.09 0.2658 B5 17.6 273.48 67.69 0.2475 A6 17.3 306.69 83.17 0.2711 B6 17.2 260.60 69.07 0.2650 -
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