基于分子链演化的NEPE推进剂基体超弹本构模型OA北大核心CSTPCD

To reveal the relationship between the evolutions of polymer chains within the NEPE propellant matrix and the hyper-elastic mechanical behavior,a multiscale approach was adopted to investigate the evolution behavior and characterization mod-el of polymer chains under different deformation states.Firstly,based on the microscopic models of components such as matrix adhesives,curing agents,and plasticizers,a dynamic model describing the evolution of cross-linked and free chain configura-tions under complex deformation states was developed through molecular dynamics simulation of the matrix system Subsequent-ly,the free energy contributed bycrosslinked and free chains was quantitatively characterized based on statistical mechanics,and a hyperelastic constitutive model considering the cross-linking and entanglement effects was established.Finally,the devel-oped constitutive model was validated by using the quasi-static tensile experimental data of NEPE propellant matrix samples.Compared with the classical Arruda-Boyce model,the constitutive parameters in the present model have real physical signifi-cances and can be obtained by experimental methods,which enables the present model to better predict the hyperelastic behav-ior of the propellant matrix under different deformation states,and thus provide model for the regulation of mechanical proper-ties and component optimization of propellant matrix.