Theory And Applications Of Laminated Plates Considering Interlayer Slip

Laminated plates have been extensively applied to various transportation infrastructures,such as the undertrack structure of slab ballastless track of high-speed railways.However,the adhesive interface often becomes the weak point of this type of structure,where shear slip is prone to occur,leading to the deterioration of the overall structural performance.In order to not only reflect the characteristics of interlayer slip of laminated plates,but also have the simple form of the plate theory,a double-layer model for laminated plates considering interlayer bi-directional slip is proposed for the first time in this paper.The theoretical framework of laminated plaates considering interlayer slip is established based on variational principles.On this basis,the laminated plate element considering interlayer slip is developed and applied to the analysis of dynamics response of the undertrack structure under train load,the assessment of the effect of partial failure of the interlaminar bonding of the undertrack structure and the simulation of interlaminar debonding process.The main studies are as follows:(1)In order to consider the imperfect interlaminar bonding characteristics of laminated plates,the interlayer relative slip is introduced,and the theoretical framework of laminated thin and medium-thick plates considering interlayer slip is established.The virtual work principle,the reciprocal theorem of work,the minimum potential energy principle,the minimum complementary energy principle and the two-and three-field generalized variational principles are derived for these two plate theories,respectively.The variational forms of free vibration and buckling stability are also given.The exact solutions for static and dynamic analyses,as well as temperature effects are obtained in the case of the laminated plates with four sides being simply supported.(2)A laminated thin plate rectangular element considering interlayer slip is constructed,and the explicit expressions of stiffness matrix,mass matrix and geometric stiffness matrix are obtained,as well as the equivalent nodal forces for temperature loads.The effectiveness of the elememt in the analysis of bending deformation,free vibration,buckling stability and temperature effects of laminated plates is verified.(3)Based on the laminated thin plate element considering the interlayer slip,the dynamic response of the undertrack structure of high-speed railways under train load and its amplification effect are analyzed.The effect of the partial failure of the interlaminar bonding on the overall performance of the undertrack structure of high-speed railways is analyzed by reducing the interlayer slip stiffness.The interlaminar debonding behavior of the undertrack structure is simulated by using the laminated plate element in combination with the bilinear cohesive zone constitutive model calibrated by the interface shear failure model experiment.