基于结构仿生的GFRP板簧层间增韧性能研究

A study of interlaminar toughness enhancement of GFRP plate spring based on structural bionics

为了提高玻璃纤维增强树脂基复合材料(GFRP)板簧的层间韧性,进而提高其疲劳寿命,本文仿照珍珠母矿物质结构单元的排列形式设计了砖砌型增韧结构的GFRP板簧。制作了同尺寸砖砌型结构和非增韧结构缩比板簧样件,层叠铺设方法按照变厚度层合板铺层递减设计原则,并对砖砌型结构和非增韧结构缩比板簧进行了刚度实验、疲劳实验和剩余刚度实验。实验结果显示:与无增韧结构GFRP板簧相比,砖砌结构GFRP板簧的刚度降低了8.4%,但疲劳性能提升了28.99%,疲劳实验后无增韧结构完全断裂,没有剩余刚度,砖砌增韧结构GFRP板簧仍具备43.52%的原始刚度。无增韧结构GFRP板簧的疲劳失效形式是层间分层,结构完全断裂;而增韧结构GFPR板簧的疲劳失效形式是层间分层被阻断,结构形成局部断裂,进行剩余刚度实验后,其断裂截面呈阶梯状。

In this study, resin-based glass fiber reinforced composite(GFRP) plate spring was designed with a brick type toughening structure by the arrangement form of mother-of pearl mineral structural elements to improve the interlayer toughness of GFRP plate springs, thereby improving their fatigue life. The same size brick masonry type structure and non-toughened structure shrinkage plate spring samples were produced, and the ply laying method was based on the decreasing design principle of variable thickness ply laying. And the mechanical properties of brick structure and non-toughened structure GFRP plate spring were compared by stiffness test, fatigue test and residual stiffness test. The experimental results show that compared with the GFRP plate spring of the non-toughened structure, the stiffness of the GFRP plate spring of the brick structure is reduced by 8.4%, and the fatigue performance is improved by 28.99%. During the fatigue test, the non-toughened structure is completely broken without residual stiffness, and the GFRP plate spring of the brick toughened structure still has the original stiffness of 43.52%. The fatigue failure of GFRP plate springs without toughened structure is in the form of delamination between the layers and complete fracture of the structure. In contrast, the fatigue failure of the toughened structure GFPR plate springs is in the form of interlaminar delamination being blocked and the structure forming a local fracture, for which the fracture cross section is stepped after the residual stiffness test.