Research On The Coupling Mechanism Of Highly Nonlinear Solitary Waves And Damaged Composite Material Plates

As a good information carrier,solitary waves have broad application prospects in the field of non-destructive testing.Based on the coupling mechanism of highly nonlinear solitary waves in one-dimensional(1-D)particle chains with damaged composite material plates,we explore the influence of characteristic parameters of damaged composite material plate on reflected solitary wave,and analyze the reflection characteristics of solitary waves on the surface of the measured structure to achieve the purpose of nondestructive testing.The specific research contents are as follows:(1)Research on the coupling mechanism between 1-D particle chains and composite laminates:Based on Hertz contact law,the relationship between the contact force and compression between adjacent particles is obtained,and the differential equation of motion of 1-D homogeneous particle chains and composite particle chains is derived by using classical Newton's law.Based on the indentation law of composite materials and classical laminate theory,the differential equation of motion of composite laminate is obtained,and the differential equations for the coupling effect of the 1-D particle chains and the composite laminates are constructed.(2)The damage model of the matrix cracking of the composite material plate is established:The damage constitutive relation of composite laminates with matrix cracking is established by using Talreja tensor internal variable damage model,and the coupled differential equations of 1-D particle chain and matrix cracking composite laminates are obtained.Fourth order Runge-Kutta method is used to solve the differential equation,the change law of the velocity and the internal force of the information particle(the thirteenth particle),and the displacement curve of each particle are analyzed under the change of the thickness of the plate and the damage and other parameters,and the reflection characteristics of the reflected solitary waves in homogeneous particle chains and composite particle chains on the surface of the damaged composite laminates with different materials are obtained.(3)The damage model of the fiber fracture of the composite material plate is established:Based on the meso-mechanical model of the stiffness degradation of the composite material board after fiber fracture,the coupled differential equations of the 1-D particle chains and the fiber fracture of the composite material unidirectional board are obtained,the fourth order Runge-Kutta method is used for numerical solution,and the influence of plate thickness,damage amount and fiber volume fraction on the reflected solitary wave in homogeneous particle chain and composite particle chain is obtained.By changing the placement of the particle chain,the influence of gravity on the reflected solitary wave is analyzed.The research results of this paper provide a theoretical basis for the identification of damage types and damage levels in composite material plates by using highly nonlinear solitary waves,and are of great significance for perfecting the theory of solitary wave detection.