Research On Linear Analysis Of The Constitutive Relation Of Concrete Elastoplastic

To study elastoplastic damage constitutive relations for concrete based on Duality Disturbance.According to the non-fitting of nonlinear stress-strain curve of concrete,variation law of stress-strain is studied and put forward nonlinear constitutive model for linearization.The paper makes use of MATLAB software to plot the results of the finite element simulation,combined with ANSYS software to simulate the mechanical behavior of concrete.It has a significant influence on the deep understanding of constitutive relations,the improvement of material properties,the guidance of material enhanced design,the development of new material and energy saving.Based on the experimental data and use of non fitting nonlinear elastoplastic hardening stress-strain relationship,combining the strain can equal assume,then determine the break point of the linearize equations,function relationship and gives concrete.A linearization method of the uniaxial non-fitting nonlinear stress-strain curve given is presented.Will strengthen the stage of linearization of nonlinear stress-strain equation.Two sets of linear equations are obtained.The softening of concrete is analyzed,and puts forward to soften the decline of linear relationship.The stress strain curves of uniaxial tension and compression conditions,using numerical experiments,contrast linear curve with classic curve,to verify the rationality of the model.Introducing Kupfer test data,the strengthening phase corresponding linear curve drawing,and Popovic curve and Saenz curve contrast,can be seen that the curve of the proposed this chapter and the two curves in strengthening phase alignment is better,further verify the effectiveness of the proposed concrete the accuracy of the linear stress-strain relationship.The paper elaborates the concept of Duality Disturbance and material changes,duality disturbance equation of many materials and a comprehensive detailed explanation of the disturbance.Combined with the material of the Duality Disturbance equation,analytical linearization equation of concrete in perturbation.On the basis of concrete elastoplastic disturbed model,put forward the concept of an equation of observed stress and disturbance on the plastic strain in the disturbed state under the disturbance condition,and analyzes the relationship between plastic strain and disturbances varies.Using ANSYS finite element analysis software for uniaxial tension compression of concrete block to analyze the simulation results,analysis data is in good agreement with stress-strain curves of concrete,thus the applicability of the theory for one-dimensional mechanical behavior of concrete is validated.Using the equivalent strain and the single curve hypothesis,which extended linear curve into general stress condition.Analysis of cantilever beam under shear stress condition,selection of cross section were analyzed,and the selection of the dangerous point of the beam,the analysis of the stress,strain and plastic strain,and the disturbance function,given based on the Duality Disturbance Theory and the single curve hypothesis predicts elastic-plastic mechanical behavior of concrete under complicated stress state.