The Strength Analysis Of The Fiber-reinforced Polymer Sandwich Bridge Deck With Triangle Truss-core

In recent years, fiber reinforce plastic composite structure has been applied widely in ocean engineering field, Aerospace engineering fields and bridge engineering field. As a kind of composite bridge deck,fiber-reinforced polymer sandwich bridge deck with triangle truss-core has became one of the main forms of bridge deck due to its plenty advantages, such as:high stiffness and strength to weight ratio, good designability, excellent anti-impact and outstanding heat and sound insulation and so on. Predict the strength of the fiber-reinforced polymer sandwich bridge deck with triangle truss-core rapidly and accurately has became one of the thorny problems in the process of its application.In this paper, the main content includes:(1) According to energy theory, beam theory and deformation compatibility condition, the equations of the equivalent elastic constants of the fiber-reinforced polymer sandwich bridge deck with triangle truss-core with considering of restrain of the rib and the skin are derived. Comparing to the result of FE-based modeling,it has proved that the effect of the restrain of the rib to the quivalent elastic constants of the fiber-reinforced polymer sandwich bridge deck is significant. The accuracy of the formulations are verified by comparing to the result ofthe other existing formulations.The rules of elastic constants affected by geometrical parameters and the property of the material were analysed.(2) Based of the Phenomenological analysis and progressive damage theory, damage initiation criterion and stiffness reduction plan have been implemented in the finite element analysis (FEA) process, through coding the user subroutine (usdfld) of the finite element analysis software abaqus. A three-dimensional finite element model of composite laminates has been established to analyz the ultimate strength of the laminates with central hole under single axis tension and compression loads. Comparing to the result of the experiment, wo have found that the method to predict the ultimate strength is reliable. Finally,the effects of different size, different layer on the ultimate strength of composite laminated plate were also studied. are predicted accurately based on CDM and The results of FEA have a good agreement with experiment, although the latter method is time-consuming and high cost.(3) Based of the continuum damage mechanics and progressive damage theory,this paper has brought in the concepts of internal damage state variables and effective stress. The proposed composite lamina constitutive equation, damage initiation criterion and damage evolution criterion have been implemented in the finite element analysis (FEA) process, through coding the user subroutine (umat) of the finite element analysis software abaqus. A three-dimensional finite element model of composite laminates has been established, the ultimate strength of the laminates with central hole have been analyzed under single axis tension and compression loads. The internal damage state variables are decided by the composite material properties and its stress and strain state. Finally, Comparing to the result of the experiment, it has found that the ultimate strength are predicted accurately based on CDM and The results of FEA have a good agreement with experiment.(4) The fiber-reinforced polymer sandwich bridge deck with triangle truss-core composed of the production FBD600 has been reasonable simplified in order to establish the three-dimensional entity model. Under bending load, the ultimate flexural load of the sandwich bridge deck has been obtained. Finally, it revealed the rule of the failure of location distribution and damage extension of the triangle sandwich composite bridge panel undering the bending load and the results of the simulation is close to the experimental results.(5) According to the the equations of the equivalent elastic constants of the fiber-reinforced polymer sandwich bridge deck with triangle truss-core, FBD600 is idealized as composite laminates with three layers. With using of the composite laminated plate theory, predicting the ultimate flexural load of sandwich bridge deck rapidly and accurately is realizable. By comparison with the experimental results, the effectiveness of the proposed method is verified.