Mechanical Properties Of 3D Lattice Reinforced Foam Sandwich Composites

Traditional sandwich composites is difficult to meet the performance requirement for equipment of lightweight,high strength,because it is has many disadvantages like low bonding strength across the interface,unsatisfying sheer and flatwise compression properties.Therefore,the 3D lattice reinforced sandwich composites(3D-LRSC)were studied in this paper.The lattice structure with manufacturing feasibility was selected by finite element analysis(FEA).The influence of the lattice parameters such as stitch structure and dosage of stitching yarn on compression and flexural properties was studied by experiments and FEA.The main contents as following:(1)The new 3D lattice structure with manufacturing feasiblity and good flexuralproperties wasdesigned by finite element analysis(FEA)to reinforce the foam core of the 3D-LRSC.(2)The 3D-LRSCwas prepared by Vaccum Infusion Molding Process(VIMP)to investigate the effects of lattice structure on the compression and flexural properties.The results show that elastic modulus and compression strength of V-shape lattice reinforced sandwich composite was reduced by 19.7% and 22.6% compared with the vertical stitch structure,but the flexural rigidity,flexuralfailure load and core material sheer modulus increased by 26.8%,94.4% and 62.7%,respectively.(3)The impact of the layer of facesheet on the compression and flexural properties of the 3D-LRSC were studied.The results show that the core elasticmodulus,compression strength,flexuralfailure load,flexuralrigidity of 3D-LRSC were reduced by 19.7%,0.4%,17.5% and 4.3% respectively when facesheet-layer was decreased from 2 to 1.It indicates that the compression and flexural performance of the 3D-LRSC increase with the facesheet-thickness increasing.(4)The effects of penetration stitch on the compression and flexural properties of the 3D-LRSC were studied.The results show that the elasic modulus,compression strength,flexural failure load and flexural rigidity of the un-penetration 3D-LRSCspecimen were reduced by 17.7%,21.2%,50.8% and 13.7%compared with the penetration specimen.It indicates that the compression and flexural performance of the 3D-LRSC can be improved by penetration stitch.(5)The influence of stitching yarn on the compression and flexural properties of the 3D-LRSC were studied.The results show that the compression modulus,compression strength,flexural failureload and flexural rigidity of the 3D-LRSC were increased by 42.6%,24.2%,103.8% and 51.9% as stitching yarn increaseing from 2 to 8.It indicates that the compression and flexural properties of the 3D-LRSC increase with the increasing of the stitching-yarn dosage.(6)The compression and flexural properties were studied by FEA.The results show that the deviation between the FEA results of Z-compression modulus and experimental value is less than 13%,and the maximum error of the simulation results of the flexural rigidity and experimental value is less than 20%.It indicates that the FEA method can be used to predict the compression and flexural properties of the 3D-LRSC.