蜂窝夹芯结构用连接接头抗冲击性能研究

Study on Impact Resistance of Connection Joints for Honeycomb Sandwich Structures

夹层结构在工程领域的应用广泛,但其连接装配问题却日益突出,尤其是面临强动载荷下的作战装备,如何设计连接接头以提升结构的可靠性及维修性,是目前研究的热点.针对蜂窝夹芯防护结构在典型作战环境中的连接装配问题,设计了一种由方管锁定的快速组装连接接头,并通过泡沫子弹冲击实验以获得连接结构在不同冲量下的动态响应,随后采用有限元方法对冲击试验进行了模拟,仿真结果与实验结果吻合度较好.在此基础上,利用该有限元模型进一步探讨了方管壁厚、连接单元宽度等几何参数对该结构在泡沫子弹冲击载荷作用下的峰值挠度的影响.结果表明,较薄方管壁厚(t_(t)/t_(f)≤0.375)使得连接结构容易陷入方管压溃的失效模式导致其峰值挠度显著增大,而较小的连接单元宽度(2a/W≤0.267)将导致面板抗拉强度下降,进而削弱连接结构抗冲击性能.此外,随着连接单元宽度的不断增加,连接结构的峰值挠度呈现先减小后增大的趋势,这是由于连接单元的有效横截面积与机械互锁接触面积之间存在竞争机制.当前研究表明,这种快速组装连接接头能有效抵御动态冲击载荷,具有抗冲击吸能、便于维护更换的特点,有望应用于各型主战装备防护结构的连接,为夹层连接结构的抗冲击设计提供参考.

Sandwich structures are widely used in engineering fields,but their connection and assembly prob⁃lems become more and more prominent,especially for combat equipment under strong dynamic loads.How to design connection joints to improve the reliability and maintainability of the structure is a hot research topic at present.Aimed at the connection and assembly problem of honeycomb sandwich protection structures in typical combat environment,a quick assembly joint locked by square tubes was designed,and the dynamic responses of the connection structure under different impulses were obtained by foam projectile impact tests.Then the fi⁃nite element method was used to simulate the impact test,and the simulation results agree well with the experi⁃mental results.On this basis,the effects of geometric parameters such as wall thicknesses and connection unit widths on the peak deflections of the structure under the foam projectile impacts were further discussed with the finite element model.The results indicate that,the thinner wall thickness(t_(t)/t_(f)≤0.375)of the square tube makes the connection structure prone to collapse,leading to a significant increase in peak deflections.Howev⁃er,a smaller width(2a/W≤0.267)of the connection unit causes the panel tensile strength to decrease,thereby weakening the impact resistance of the connection structure.In addition,as the connection unit width increa⁃ses,the peak deflection of the connection structure will first decrease and then increase.This is due to the competition mechanism between the effective cross⁃sectional area of the connection unit and the mechanical interlocking contact area.The proposed quick assembly connection joint can effectively resist dynamic impact loads,has good impact energy absorption abilities,and easy maintenance and replacement.It is hopeful to be applied to the connection of various types of main combat equipment protection structures,and provides refer⁃ence for the impact resistance design of sandwich connection structures.