Analysis And Experiment On Mechanical Behaviors Of Adhesively Bonded Interface In Solid Rocket Motors

Adhesively bonded interface is a weak link in the structure of solid rocket motors,whoes mechanical behaviors directly affcet the structural integrity and storage life of solid rocket motors.The vertical storage mode of solid rocket motors and the application of the new generation of NEPE propellants pose a severe challenge to the mechanical properties of adhesively bonded interface in solid rocket motors.How to accurately describe and analyze the mechanical bahaviors of adhesively bonded interface in solid rocket motors has been the focus of reseachers.This paper established PPR cohesive zone models applied to the mode ? and mode ? debonding analyses of insulation/propellant adhesively bonded interface in solid rocket motors,and designed suitable interface debonding tests.Inverse optimization method is used to identify the parameters of the mechanical models of the adhesively bonded interface.Furthermore,the debonding analyses of solid rocket motors under typical loads is carried out.The main contents are as followsBased on the secondary development of UEL subroutine based on ABAQUS,a 2D PPR cohesive elememt is established.The damage evolution mechanism of bilinear and PPR cohesive zone model are comparatively analyzed.The two-dimensional PPR cohesive element is secondary developed based on the UEL of ABAQUS.The secondary developed PPR cohesive element is applied to static computations of two kinds of typical interface elements in double cantilever beams and single-lap joints structures.The influence of eight characteristic parameters of PPR cohesive zone model is analyzed and the correctness of the PPR cohesive element is verfied.The mode ? debonding test of insulation/propellant adhesively bonded interface is designed,and the PPR cohesive zone model suitable for mode ? debonding analyses of insulation/propellant adhesively bonded interface in solid rocket motors is established.Based on the mode ? debonding behaviors of insulation/propellant adhesively bonded interface,the double cantilever sandwich beam test is designed.Finite element model for mode ? debonding analyses is established using the PPR cohesive zone model.The parameters of PPR cohesive zone model suitable for mode ? debonding are obtained by combining the test and simulation analyses with inverse optimization method.Considering two typical load conditions including solidfication cooling as well as temperature cycling process,the mode ? debonding mechanical behaviors of Insulation/propellant adhesively bonded interface in a solid rocket motor is analyzed.The mode ? debonding test of insulation/propellant adhesively bonded interface is designed,and the PPR cohesive zone model suitable for mode ? debonding analyses of insulation/propellant adhesively bonded interface in solid rocket motors is established.Based on the mode ? debonding behaviors of insulation/propellant adhesively bonded interface,the single-lap joint test is designed.Finite element model for mode ? debonding analyses is established using the PPR cohesive zone model.The parameters of PPR cohesive zone model suitable for mode ? debonding are obtained by combining the test and simulation analyses with inverse optimization method.Considering two typical load conditions including gravity and wave loads,the mode ? debonding mechanical behaviors of Insulation/propellant adhesively bonded interface in a vertical storage solid rocket motor is analyzed.The research achievement in this paper can provide a reference for the refined structural integrity analyses of solid rocket motors considering mode ? and mode ? debonding of adhesively bonded interface,and provide technical support for reliability analyses and storage life prediction of solid rocket motors in the research and application departments,which has important engineering value and broad application prospect.