Study On Mechanical Properties Of High Strength Concrete Based On Meso-Mechanics Numerical Method

Existing research focuses on the macro-mechanics properties of concrete,with less involvement at the mesoscopic and microscopic levels.On the mesoscopic level,concrete is a three-phase material composed of cement matrix,aggregate and interfacial transition zone between them.High Strength Concrete has excellent mechanical properties and has become the development direction of concrete technology in the future,but related research is still in its infancy.In this paper,a High Strength Concrete mesoscopic model is established based on the random aggregate method,and the macro-mechanics properties of High Strength Concrete are analyzed at the mesoscopic level.The main research work of the thesis is:(1)Based on the random characteristics of aggregate distribution and morphology,the Walraven formula was used to determine the aggregate distribution of the Section of concrete specimen.The secondary development of ABAQUS was carried out,and Python programming method was used to generate randomly distribution numerical model of aggregate particles.(2)The finite element mesh generation is applied to the random aggregate model by means of ABAQUS,and the corresponding mechanical performance parameters of the mesoscopic elements are given.Based on the damage analysis method,the finite element calculation program is applied to generate a High Strength Concrete numerical model that can be numerically simulated.(3)Taking C80 High Strength Concrete as the research object,the uniaxial tension and compression simulation analysis were carried out by using the generated numerical model,and the stress-strain curve and damage element evolution figure of High Strength Concrete were obtained.In addition,the numerical simulation of the tensile and compressive properties strength of C80 High Strength Concrete after high temperature was given.For comparative analysis,this paper established a mesoscopic numerical model of C20,C40,C60 concrete,and considers the influence of end constraints.Due to the different interfaces,ordinary concrete is essentially different from High Strength Concrete.Based on the meso-mechanics numerical method,the mechanical properties and failure mechanism of High Strength Concrete are studied,and the effect of high temperature on the mechanical properties of High Strength Concrete is discussed.This study can provide a reference for further discussion on the mechanical properties of High Strength Concrete under complex stress.