碳纤维复合材料双胞日字形管轴向压溃吸能特性研究

ENERGY ABSORPTION OF DOUBLE-CELL CFRP SQUARE TUBES UNDER AXIAL COMPRESSION

多胞复合材料管制备难度大,本文研究探索了碳纤维复合材料(Carbon Fiber Recinforced Plastic,简称“CFRP”)日字形管的一体化制备工艺方法,研究了日字形方管轴向压溃下的破坏模式和吸能性能,比较了等质量和等壁厚日字形管与单胞方形管的性能差异。研究表明,CFRP日字形管的吸能性能低于CFRP单胞方管的。与单胞方管相比,等质量的日字形管和等壁厚的日字形管比吸能分别下降了49.05%和3.34%。这是由于为保持日字形管和方管截面质量一致,日字形管需要减少壁厚,这将易引起管发生低吸能的中部断裂破坏模式,而等壁厚的日字形管与方形管相比,由于中间加入了筋板,将导致中间T形角区域破坏不充分。设置触发角是一种能有效降低峰值力并提升比吸能的方法,设置触发角后,峰值力降低了26.21%~41.74%,比吸能提高了2.52%~11.31%。不同于金属管可以通过多胞来增加角从而使其吸能显著增强,碳纤维管多胞化并不能有效提高所制备碳纤维复合材料日字形管的吸能性能。

This paper aims to study the energy absorption characteristics of CFRP double-cell tubes under axial compression.A preparation process of integrated carbon fiber multi-cell square tubes is proposed.The influence of energy absorption characteristics of multi-cell tubes with equal mass and wall thickness is explored.Finally,the energy absorption mechanism of multi-cell tube failure is analyzed by observing the failure modes of the tubes.The experimental results show that the energy absorption of CFRP single-cell tubes is higher than that of double-cell tubes.Compared with single-cell tubes,the specific energy absorption of equal-mass and equal-wall-thickness double-cell tubes decreased by 49.05%and 3.34%,respectively,which was due to the phenomenon of central crack and incomplete energy absorption in some region.Setting trigger is an effective way to reduce peak force and increase specific energy absorption.After setting trigger,peak force decreases by 26.21%~41.74%,and specific energy absorption increases by 2.52%~11.31%.Therefore,for the CFRP multi-cell square tubes,the double-cell tubes can not effectively enhance the energy absorption characteristics,and the destruction of the single-cell tubes are more stable than that of the double-cell tubes.