| Spacer fabric is a kind of preformed unit of textile structure composite material.The resin matrix composite formed by this material has the advantages of light weight,corrosion resistance,impact resistance and high specific strength,one of its potential applications is as a reinforcing material for fan blades.In this paper,according to the performance requirements and cost performance of fan blade,a new type of pillar supported hollow spacer fabric is designed,and e-alkali free glass fiber is selected as the raw material of pillar supported hollow spacer fabric.In order to reduce the probability of warp voiling,breakage and warp tension inequality in weaving process,the fabric surface layer and the joint portion are select the plain fabric.Using Tex Gen fabrics simulation software to draw the structure of the fabric,according to the structure drawing out the fabric organization diagram and the upper machine diagram,forming a complete set of pillar support of hollow fabric weaving technology,for the research personnel in this direction to do a lot of basic work.Resin composite was conducted on the fabric based on the hand paste method.In order to enhance the bonding strength of the interface,silane coupling agent KH550 was used to pretreat the prefabricated parts.In order to improve the brittleness of the resin,a certain amount of montmorillonite was added to the resin liquid to be coated.Based on the bending properties of the composites,the optimal addition amount of montmorillonite was discussed,and the modification mechanism was characterized by Infrared spectrometer(FTIR),thermogravimetric analyzer(TG),and X-ray diffraction(XRD).Based on the modification of the composite material,the hollow part was filled with rigid polyurethane foam to enhance the overall mechanical properties of the final composite material.The influence of prefabricated structure(thickness,spacing of splicing yarn)on the mechanical properties of composites was analyzed.Finally,the process of compression,bending and lateral compression is simulated by finite element software.The results showed that compared with the unmodified composite material,the montmorillonite content is 3wt.%,the maximum bending load is 113.6N,which is 12.39%higher than the pure epoxy resin composite;The reaction between resin and montmorillonite was characterized by FTIR、XRD and TG,and the observation by scanning electron microscope(SEM)showed that the modification of the coupling agent/montmorillonite improved the mechanical properties of the composites;With the increase of the thickness of prefabricated parts,the flat compression strength and bending strength of the composites filled with polyurethane foam decreased,while the bending stiffness and side compression strength increased;The compression strength,bending strength,bending stiffness and lateral compression strength of the filled polyurethane foam composite decreased with the increase of the distance between the yarn bundles of the prefabricated core material;The results of finite element simulation show that the flat compressive stress distribution of the composite is relatively uniform.The bending stress is mainly concentrated in the pressing area of the upper head,while the lateral compressive stress is mainly concentrated in the clamping area of the upper and lower chuck.By comparing the finite element simulation results with the actual test results,the availability of finite element simulation is proved,which provides a theoretical basis for the researchers in this field in the future. |
