轴向和斜向加载下复合材料-金属-泡沫混杂管件的压溃吸能机制

Crushing energy absorption mechanisms of the composite-metal-foam hybrid tubes under axial and oblique loads

  • 摘要: 本文旨在探讨碳纤维增强树脂(Carbon-fibre-reinforced polymer,CFRP)-铝合金-泡沫铝混杂管件在轴向(0°)和斜向(10°)荷载下的压溃变形特性和能量耗散机制。首先对纯碳纤维管(CF)、纯铝管(Al)、纯泡沫铝(Af)、Al-Af混杂管和CF-Al-Af混杂管进行了准静态压缩试验;在0°和10°的加载角下,Al-Af混杂管的能量吸收总是高于单一部件的能量吸收总量;与单一组分能量吸收之和相比,CF-Al-Af混杂管的能量吸收在0°加载角下减少,而在10°加载角时则显著提高。接着,在LS-DYNA中开发了混杂管件和相应的单一部件的数值模型,仿真结果表明,铝管能量吸收的提升促进了Al-Af和CF-Al-Af混杂管承载能力的提升,原因在于相比于单一铝管的“对称-钻石”混合变形,混杂管中的铝管发生了更稳定的对称变形,然而外部CF管能量吸收的降低主要削弱了CF-Al-Af混杂管的能量吸收,原因在于混杂管的CF管受到内部铝管的挤压出现了轴向撕裂失效。最后,建立了CF-Al-Af混合管和相应的单一管件在轴向荷载下的平均压溃载荷解析模型,结果表明,所开发的解析模型可以较好地预测混合管和单一部件的平均压溃载荷。

     

    Abstract: This study aims to explore the crushing deformation characteristics and underlying energy dissipating mechanisms of carbon-fibre-reinforced plastic (CFRP)-aluminum-aluminum foam hybrid tubes under both axial (0°) and oblique (10°) loads. Quasi-static compressive tests for net CFRP (CF) tubes, net aluminum (Al) tubes, net aluminum foams (Af), Al-Af hybrid tubes and CFRP-Al-Af hybrid tubes were performed first. The energy absorptions of the Al-Af hybrid columns are always higher than that of the sum net parts under loading angles of 0° and 10°; the energy absorption of the CF-Al-Af hybrid columns reduces under a 0° loading angle while improves remarkably under a 10° loading angle compared with the sum of net parts. Next, numerical models for these hybrid tubes and the corresponding net parts were developed in LS-DYNA, and numerical results indicate that the energy absorption improvement of Al tubes promotes the load-carrying enhancement of Al-Af and CF-Al-Af hybrid tubes, because the Al tubes in hybrid happen more stable symmetric deformation compared with the “symmetric-diamond” hybrid deformation of the net Al tubes; whereas the energy absorption reductions of external CF tubes primarily decrease energy absorption of CF-Al-Af hybrid tubes, because the CFRP tubes in the hybrid occur axial splitting failure due to compressions of inner Al tubes. Finally, the analytical models on mean crushing forces for CF-Al-Af hybrid columns and corresponding net components under axial load were developed, and the results indicate that the developed analytical models can better predict the mean crushing forces of both hybrid columns and net parts.

     

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