Flexural Behavior Of Composite Sandwich Beams With BFRP Ribs

Fiber reinforced composite sandwich panels use high strength fiber composite panels as upper and lower panels,lightweight materials as the core.Under the action of load,the ordinary sandwich panel is prone to brittle failure such as interface delamination and core shear,which limits its application in the field of civil engineering.In view of the above problems,this paper uses basalt fiber(BFRP)with high strength,high performance-to-price ratio and green environmental protection as the panel and web materials,and puts forward the web reinforced BFRP sandwich plate.The influence of various parameters on the bearing capacity and failure mode of the new sandwich plate is studied,and the particle swarm optimization algorithm is used to optimize the design of the sandwich plate,which provides guidance for the actual production of the new component.The main research contents and conclusions of this paper are as follows :(1)The equivalent theory of laminated plate,the elastic analysis theory of sandwich plate and the calculation method of ultimate bearing capacity are summarized.Based on the energy variation principle,the web reinforced core layer is homogenized,and the theoretical calculation method of flexural bearing capacity of web reinforced sandwich plate is proposed.(2)The three-point bending test of BFRP sandwich plate was simulated by Abaqus finite element analysis software,and the breaking mode of the sandwich plate was studied.The failure mode of webless reinforced BFRP sandwich plate is mainly foam shear failure.For the web reinforced BFRP sandwich plate,increasing the volume content of the web in the core layer can change the failure mode of the sandwich plate : when the volume content of the web is less than 2.67%,the shear failure of the web occurs;when the volume content of the web is greater than 2.67%,the compression failure of the panel occurs.Compared with the reinforced sandwich plate without webs,the existence of webs increases the bearing capacity of the sandwich plate by 42.68%.(3)The influence of panel thickness,web thickness,web spacing,core thickness and core foam density on the bending capacity was studied.The results show that increasing the thickness of the surface layer,increasing the volume content of the web,increasing the height of the core layer and increasing the core foam density can increase the stiffness of the web reinforced BFRP sandwich plate and improve the bending capacity of the sandwich plate;(4)Comparing the results of elastic analysis theory and ultimate bearing capacity theory of sandwich plate with the finite element results,it is found that the theoretical results are in good agreement.By comparing the accuracy and convenience of the three theories in the deflection calculation of web reinforced BFRP sandwich plate,the first-order shear deformation theory is recommended for the practical use of web reinforced BFRP sandwich plate.(5)On the basis of theoretical verification,the influence of normal service deformation requirements and ultimate bearing capacity requirements of web reinforced BFRP sandwich panels on the range of parameters is summarized,and the main limiting condition of engineering application bearing capacity of web reinforced BFRP sandwich panels is determined as normal service deformation requirements;secondly,based on particle swarm optimization algorithm,the configuration optimization method for web reinforced BFRP sandwich plate is proposed,and the optimization design of the component with the smallest thickness,the lightest weight and the lowest price is carried out,which provides guidance for the application of the structure in practical engineering.