Research On Two Dimensional Finite Element Model Of Recycled Concrete Based On Meso-Level

Based on the macro-level,the recycled concrete material is considered as homogeneous material and a lot of experiments are carried out.The experiment will be affected by the factors such as conditions,environment,human resources,material resources and financial resources.In many cases,it is difficult to carry out the experiments and explain the problems of the crack propagation fully,the stress-strain characteristics and the damage evolution law of the recycled concrete.Therefore,from the microscopic point of view,it is necessary to further solve the problems on the macro-level,and the meso-level numerical simulation method is an effective and feasible method in the study of recycled concrete.But there is a lack of mature meso-level finite element analysis model.In this paper,we study the two-dimensional meso-aggregate-model of recycled concrete.The four main work of this paper is as follows:(1)Based on the random characteristics of recycled concrete aggregate,the original aggregate morphology and distribution,using Monte Carlo method,random number generation principle,Fuller series and formula besides the relevant theoretical bas is,according to previous experimental work,the application of ANSYS software APDL parametric programming language,compile general algorithm flow and command flow in accordance with the characteristics and the requirements.According to the characteristics of aggregate distribution,two kinds of recycled aggregate concrete are established.By filling different aggregate particle number(25 teeth,50 teeth,75 teeth and 100 teeth),different amount of recycled aggregate(0%,25%,50% and 75%)and different random number(4)of three variable parameters to verify two random aggregate model algorithm.(2)According to the digital image processing technology and the previous successful application in engineering research work of recycled concrete,this paper e stablished a new micro aggregate model mainly uses three kinds of software,two kinds of means a digital image aggregate model.Digital image model of image source distribution of aggregate aggregate in recycled concrete block cutting and extraction,three kinds of recycled coarse aggregate quantity is established based on the digital image process of recycled concrete aggregate model(0%,30% and 50%)of the meso finite element model of aggregate.(3)According to the needs of the project,the design of the test group of the recycled aggregate content of the mixture: 0%,30% and 50%,mix design and test block maintenance in accordance with the test standard test.The three work is measured,that is,the cube compressive strength,the rupture process and the stress-strain curve.The influence of two kinds of variables of recycled coarse aggregate on the strength of recycled concrete was studied.(4)Using three kinds of models algorithms and processes,it is developed to satisfy the test requirements of the three micro-aggregate-model,simulate three groups cube compressive test with different amount of recycled aggregate of the strain variation,macro mechanical response and fracture morphology development.Through all of the above analysis,the generation process,simulation results and model the advantages and disadvantages of the three models were compared and analyzed from the model that recycled concrete has the significance of popularizing model of recycled concrete meso random polygon aggregate model.Finally,the results of the model are compared with the results of other researchers,and the results are in good agreement with the experimental results.