Progressive Damage And Failure Of Woven Composites Based Muti-scale Macro-meso Modelling Method

In recent years,in the context of increasing production demand for composite materials in industrial production,the research on the stiffness,strength and damage mechanism of fiber reinforced composites has been a hot and difficult problem in solid mechanics.Many scholars have given answers from the aspects of experimentation,theory and simulation,but there are still two major problems to be solved urgently.It mainly includes the qualitative and quantitative description of the progressive damage mechanism of the woven composite under the quasi-static load.The method of damage quasi-test and failure model of the woven composite material.Based on the quasi-static tensile and compressive tests of woven composites,this paper uses the macroscopic and mesoscopic mechanical characteristics obtained from the tests,including the stress-strain curve,the acoustic emission energy accumulation curve and the whole field strain results.Based on the theory of continuous damage mechanics and progressive damage evolution,a modified constitutive model is proposed,which analyzes and predicts the progressive damage and failure of woven composites.The main work of this paper is as follows:Firstly,the tensile and compressive tests of twisted weave composites were carried out to analyze the failure process of woven composites.In order to analyze the state and course of the microscopic failure mode in the quasi-static material of the woven material and the influence on the macroscopic mechanical response of the material,the evolution of the internal damage state of the material with the external load is analyzed by means of acoustic emission(AE)monitoring.The stress distribution of the macroscopic strain field of the material with the load and damage is analyzed by digital image correlation method(DIC).Based on the quasi-static test process and the results,the macroscopic and meso damage evolution laws are analyzed based on the changes of the acoustic emission signal and the whole field strain distribution along with the loading process of the whole loading,combined with the macroscopic mechanical response and the meso damage progressive process.And provide the experimental basis for the progressive damage analysis model.Secondly,the numerical analysis part.Second,the numerical analysis part.Based on the conclusion of the classification of different failure criteria in the world,based on the Puck failure criterion and the extended three-dimensional Hashin failure criterion,a progressive damage model considering the meso failure mechanism is proposed.From the microscopic point of view,consider the different failure modes of the constituent materials.The failure mode of the fiber bundle is mainly divided into fiber failure mode(FF)and inter-fiber failure mode(IFF).Based on the three dimensional A.Matzenmiller anisotropic damage constitutive equation,the damage internal variables characterizing different failure modes are introduced.Combined with the ABAQUS user subroutine interface,a VUMAT subroutine of the progressive damage evolution model based on the Puck and Hashin failure criteria is written.Finally,the above model was used to analyze the progressive damage of T800H-6k/803 A carbon fiber double-horse resin matrix fabric composites,and the numerical results were compared and analyzed.According to the actual size of the woven composite material,the representative volume unit cell is extracted;the geometric model is established;the Hypermesh preprocessing software is introduced into the periodic grid.The periodic boundary conditions were applied in commercial finite element software Abaqus and the progressive damage and failure behavior of the material under uniaxial tensile load were analyzed.The reliability of the theoretical model and the user subroutine and the source of the error are verified by comparing the results of the progressive damage evolution analysis based on the representative volume cells with the damage evolution information obtained by the acoustic emission monitoring.In summary,this paper studies the failure mode and progressive damage behavior of the woven composite at the mesoscale scale from the aspects of experiment and numerical simulation.The progressive damage evolution model of the three-dimensional complex stress state based on the mesoscale scale is established.By comparing the predicted results with the experimental results,the progressive damage evolution model of the material under the quasi-static load is obtained.It is proved that the simulation method has good results in predicting the stiffness of woven composites.