Homogenizing interfacial shear stress in brick-and-mortar structured composites via gradient modulus for enhanced mechanical properties  

通过模量梯度化设计实现砖-泥结构界面剪切应力均匀化以获得更高的力学性能

作　　者：Yang Gao Jiawei He Jie Jiang Jianping Zuo 高阳;何佳伟;蒋洁;左建平

机构地区：[1]School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing,100083,China

出　　处：《Acta Mechanica Sinica》2024年第6期115-124,共10页力学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.12202447);China Postdoctoral Science Foundation(Grant No.2021M703289);the Fundamental Research Funds for the Central Universities(Grant No.2023ZKPYLJ04);Excellent Youth Team Funding Project of Central Universities(Grant No.2023YQTD01).

摘　　要：Inspired by nature,various biomimetic materials have been synthesized for enhanced mechanical properties,among which composites with brick-and-mortar structures attract the most attention.In such bio-inspired composites,the matrix layer mainly functions to transfer load between bricks through shearing,while the shear stress in the matrix is not uniform but highly concentrated on the interface ends,which tends to initiate cracks and evoke interface delamination in composites.To enhance the composites’resistance to interface delamination,we propose to homogenize the shear stress by adopting a matrix with a gradient modulus.A theoretical solution to the optimal gradient modulus of the matrix layer is obtained,followed by computational validations.Moreover,composites with such functionally graded matrices are further demonstrated to possess higher elastic limits,higher resilience,and flaw tolerance than the uniform controls.The results of this paper should be of great value to the design and synthesis of advanced structural materials for superior mechanical performance.受大自然启发,人们合成了各种仿生材料以获得更高的力学性能,其中具有砖-泥结构的复合材料备受关注.在这种仿生复合材料中,基体层主要通过剪切在砖之间传递载荷,然而基体中的剪切应力并非均匀分布,而是高度集中在界面边缘,这往往会引发裂纹并引起复合材料的界面分层.为了增强复合材料抵抗界面分层的能力,本文提出将基体的模量进行梯度化设计,以实现基体中剪切应力的均匀分布.通过理论分析得到了基体模量最优梯度分布的解析解,并通过数值模拟进行了有效验证.此外,与基体均匀的复合材料相比,这种基体梯度化设计的复合材料具有更高的弹性极限、更高的回弹性和缺陷容忍性.本文的结果对设计和合成具有优异力学性能的先进结构材料具有重要意义.

关 键 词：Stress concentration Interface delamination Brick-and-mortar structure Composite 

分 类 号：O34[理学—固体力学]