Research On Constitutive Model Of Masonry Structure Based On DSC Theory

In this paper,Desai’s Disturbed State Concept constitutive model is explained in detail.In this model,the RI state is a hierarchical single yield surfaceδ₀ plastic model,and the FA state is an ideal state.The experimental results can only be infinitely close to the FA state.Residual stress is used to represent the response of FA state.The RI and FA states are coupled with the perturbation function D.The concept constitutive model of the nonlinear elastic disturbance state of the masonry prism is established.The RI state uses the hyperbolic model to simulate the stress of the masonry prism under uniaxial compression using the nonlinear elastic disturbance state constitutive model of the masonry prism.The strain response,the simulated prediction results match the experimental construction results.Then the stress-strain response of the masonry structure is analyzed by using the concept theory of disturbance state.According to the basicδ₀ model of Desai’s hierarchical single yield surface model,the basic properties of the model,the solution process of the parameters,theδ₀ model parameters of the masonry structure are obtained,and the main parameters of theHISS-δ₀ model of ₂Q loess are analyzed by MATLAB.The effect of the shape of the yield surface.Then theHISS-δ₀ model is used to represent the RI state of the DSC model,and the elastoplastic disturbance state constitutive model of the brick masonry is established.The model is used to predict the stress-strain response of the brick masonry.The prediction results show that the DSC/HISS-δ₀ elastoplastic model can be used to analyze the masonry structure.The elastoplastic constitutive relation of Desai’sHISS-δ₀ model is derived,the elastoplastic relation matrix is determined,and the logic algorithm of programming is written in detail.Then,using the user material subroutine secondary development platform UMAT provided by finite element ABAQUS,theδ₀ model in the Desai hierarchical single yield surface model is written into the ABAQUS callable 3D material subroutine using FORTRAN 90 language.Finally,ABAQUS was used to call the subroutine written in this paper to perform uniaxial compression test on the masonry prism to obtain displacement and strain.