Theoretical Study On Mechanical Properties Of Solid-Liquid Composites Containing Elliptical Liquid Inclusions

This paper mainly explains the effects of liquid pressure and surface tension,substrate material,inclusion shape and size on Young's modulus and stress distribution of composites containing elliptical liquid inclusions from both theory and simulation.In the theoretical part of this paper,we consider the interface stress seriously and use the complex function method to analyze the distribution of stress at the interface of elliptic compressible liquid inclusion in the infinite length linear elastic plane under the action of uniform distal stress,and research the stress field of solid-liquid composite material.The effects of liquid pressure increment,liquid compressibility,inclusion shape and surface tension on stress distribution and deformation of composites were investigated.In addition,the effective plane strain young's modulus of solid-liquid composite material with circular liquid inclusion is derived,and the influence of liquid pressure and surface tension on it is investigated.When the volume modulus of the liquid is greater than or equal to the young's modulus of the matrix,the increment of the liquid pressure cannot be ignored;when the size of the liquid inclusion is smaller than the length of the elastic capillary,the influence of the surface tension on the solid-liquid contact interface cannot be ignored.Both liquid pressure increment and surface tension can increase the effective plane strain young's modulus of the solid-liquid composite material containing circular liquid inclusion and reduce the stress concentration coefficient at the end of liquid inclusion.In this paper,the relationship between liquid compressibility,inclusion shape and surface tension and material stress distribution is verified by finite element analysis.Simultaneous simulation results of hard composites and soft composites with liquid inclusions were obtained.The results show that when the soft substrate material contains liquid inclusions,the Young's modulus of the overall material can be effectively improved.In addition,the paper also explores the relationship between the Young's modulus of the material and the volume fraction of the liquid during the step-by-step loading of the composite material.The results show that the Young's modulus of the material increases rapidly with the increase of the liquid volume fraction,then increases slowly,and finally tends to a certain fixed value.Finally,the composite material with multiple identical elliptical liquid inclusions was simulated.Considering the interaction between inclusions,the relationship between the Young's modulus of the composite and the volume fraction of liquid inclusions was investigated.The results show that the Young's modulus of composites containing single liquid inclusions increases with the increase of liquid volume fraction,and the Young's modulus of a composite containing multiple liquid inclusions decreases as the liquid volume fraction increases.