Modeling Method Of Prefabricated Shear Wall Structure Considering Random Defects Of Sleeve Grouting

The quality of component connectors is related to the performance and safety of prefabricated concrete structures.Grouting material is one of the most commonly used materials in the construction of prefabricated concrete structures.It is difficult to avoid random defects in the process of grouting construction,and directly affect the resistance performance of connectors and structures.In this paper,a three-dimensional random defect modeling method for grouting materials was first proposed,and then an improved CDP model(MCDP)which can consider the relationship between damage factors and strain rates of grouting materials was developed.An analysis model of assembled shear wall structure that can consider the random defects of grouting sleeve was established.The influence of random defects on the static and dynamic tensile mechanical properties of grouting sleeve connectors was studied,and the dynamic response characteristics of assembled shear wall members under explosion load were analyzed.The research results can provide a technical approach for construction quality control and resistance performance evaluation of prefabricated concrete structures.The main contents are as follows:1.The random sphere was used to simulate the grouting defects,and the construction method of three-dimensional random defect model of grouting material based on ABAQUS python script was established.The random defects were meshed by pixelated grid,and the finite element model of three-dimensional meso refinement for calculationthe was generated.The three-dimensional random defect model of grouting material reproduces the random characteristics of pore defects caused by the grouting construction of prefabricated buildings,simplifies the analysis process and improves the calculation efficiency.2.Aiming at the defect that the damage of ABAQUS CDP model is independent of strain rate,the improved CDP model(MCDP)considering the correlation of damage factor rate was established based on VUSDFLD subroutine.Under static load,the results calculated by MCDP model are in good agreement with those of CDP model.The MCDP model was used to simulate the continuous and sudden increase and decrease of strain rate during the actual strong dynamic load,and the results show that MCDP model can better describe the damage softening process of materials.MCDP model was also used to simulate the dynamic response of RC beam under explosion load,and the calculated results are in good agreement with the test,which further verifies the reliability of the proposed MCDP model.3.Using the three-dimensional random defect modeling method of grouting materials considering random defects,and the reinforced grouting sleeve specimens with different defect contents were simulated and analyzed.The analysis results show that with the increase of defect content,the failure mode of grouting sleeve changes from tensile failure of steel bar to pullout failure of steel bar.Increasing the anchorage length and diameter of steel bars can improve the ultimate bearing capacity of specimens.With the increase of loading rate,the ultimate bearing capacity of the specimen increases gradually,and the corresponding displacement decreases.4.Further through numerical simulation,the dynamic response of assembled concrete shear wall with different grouting defects was compared and analyzed.Based on conwep model,the effects of TNT equivalent and explosive explosion height on the anti explosion performance of shear wall were studied.With the increase of explosion load,the peak displacement of shear wall increases continuously.By increasing the explosion height of explosive,the anti explosion performance of prefabricated shear wall is obviously improved.Sleeve grouting defects directly affect the connection performance of prefabricated joints.When the grouting is not full,the overall stiffness of prefabricated shear walls will be reduced.