Energy Absorption Characteristics And Connection Test Of Carbon Fiber Composite Truncated Cone Tubes With Different Lay-up

Carbon fiber composite materials are considered as the replacement of metal materials for energy absorption components of automobiles due to their light weight and good energy absorption performance to absorb energy in the event of a car collision and protect the passengers.But there are still several technical problems related to the application of composite materials that need to be solved,for example,low cost molding method,joint technology,and so on.In order to explore the effect of different lay-up structure and different semi-apical angle on the energy absorption performance of carbon fiber composite material truncated cone tubes and the problem of their connection with metal fittings,composite tubes with different lay-up methods and different semi-apical angle were designed and fabricated for quasi-static compression test.First of all,the truncated cone tubes with lay-up structures of(90₁/0₆)_s,(90₂/0₅)_s,and (90₃/0₄)_s,and semi-apical angle of 0°,5°,and 10°respectively were designed,(in which one with the semi-apical angle of 0°is cylindrical tube).And furthermore,the truncated cone tubes with semi-apical angle of 0°were selected to investigate the effect of thermal aging treatment including 80h and 160h at 100?.Experimental results show that:The lay-up structures have effects on the energy absorption performance of the truncated cone tubes with 0°semi-apical angle.The energy absorption and failure stability are not much different between these two lay-up methods of(90₁/0₆)_sand(90₂/0₅)_sof truncated cone tubes with 0°semi-apical angle.However,the tubes of(90₃/0₄)_s are quite difference from the other two types,in which specific energy absorption is about 16%lower.For those tubes which were made of carbon fiber prepreg used in this research,its energy absorption performance is affected under thermal aging at 100?.After 80h and 160h thermal aging,its energy absorption efficiencies are increased by about 17%compared with the sample without thermal aging one.Secondly,the quasi-static compression tests were performed on truncated cone tubes with 5°and 10°semi-apical angle of(90₁/0₆)_s,(90₂/0₅)_s,and(90₃/0₄)_s lay-up structures.Based on the comparison of 0°semi-apical angle tubes,the failure mode and energy absorption performance between tubes of different semi-apical angle types and different lay-up methods types were analyzed.Experimental results show that:For tubes of the same lay-up structure with different semi-apical angle structure,although there are differences in the appearance failure pattern due to the shape change of the semi-apical angle,the failure modes are similar,and there is no significant difference in the energy absorption efficiency.While for the tubes of the same semi-apical angle structure but different lay-up structure,the difference is obvious in energy absorption efficiency.And the energy absorption efficiency of both(90₁/0₆)_s and(90₂/0₅)_s lay-up methods are also higher than that of(90₃/0₄)_s.Finally,the 0°semi-apical truncated cone tubes with different lay-up structure were drilled holes in the tube wall,and performed the quasi-static compression test to analysis the effect of the holes on the energy absorption performance of the tubes.In addition,pin connection and compression tests were carried out on the open-hole samples inserted into the designed metal cylindrical clamping groove.The following are found that:There are no obvious differences on energy absorption efficiency of the 0°semi-apical truncated cone tubes between the open-hole samples and the un-open hole ones,that is to say that the hole does not have obvious damage.Although due to the contact and compression of the pin and the hole,the tubes of the suspended connectors are internally damaged and unable to make the implementation of effective energy absorption,the non-suspended connectors do not reduce the energy absorption of the carbon fiber composite tubes,and there is no obvious damage around the hole.