各种模式的轴压薄壁方形管的耗能研究

Energy Absorption of Axially Compressed Thin-Walled Square Tubes with Patterns

建议在一般薄壁方形管的表面增加一些模式，以增强其在轴压荷载作用下的耗能能力。利用非线性有限元程序LS-DYNA进行类静力轴向挤压分析，并利用基本的锥形单元构建两种类型的钢管，A形管主要是控制相对较薄方管的进一步破坏；而B形管主要是建立新的破坏模式，以期在结构破坏时能耗散更多的能量。总共对长度为120mm，厚度为1.2mm和宽度为40或60mm的30个钢管进行了模拟。数值结果表明：所有的A形管都发展了扩展破坏模式，总质量增加不超过5％，并且比传统薄壁方形管耗散的能量多15％～32．5％。与此同时，在B形管中发现一种新的破坏模式，被称为八边形破坏模式，其耗能能力较之传统钢管增加了54％～93％。同时还讨论了各种模式对管耗能的不同影响。

The paper suggests the introduction of patterns to the surface of conventional thin-walled square tubes to improve the energy absorption capacity under axial compressive loads. A quasi-static axial crushing analysis has been conducted numerically by the nonlinear explicit finite element code LS-DYNA. Two types of patterns constructed using the basic pyramid elements were introduced. Type A pattern was aimed at triggering the extensional mode for relatively thin square tubes whereas type B pattern was intended to develop new collapse mode capable of absorbing more energy during collapse. A total of 30 tubes with a length of 120 mm, thickness 1.2 mm and widths of 40 or 60 mm were simulated. Numerical results showed that all tubes with type A patterns developed the extensional collapse mode instead of the symmetric collapse mode and absorbed about 15%-32.5% more energy than conventional thin-walled square tubes with a mass increase less than 5%. Meanwhile, a new collapse mode named octagonal collapse mode was observed for tubes with type B pattern and the energy absorption of tubes developing this mode increased by 54% - 93% compared with the conventional tube. The influence of various configurations of the patterns on the deformation and energy absorption of the tubes was also discussed. The paper opens up a new avenue in design of high energy absorption components.