Low-velocity Impact Response And Numerical Simulation Of Stitch-reinforced Multilayer Foam Sandwich Composites

This article takes basalt fiber suture reinforced foam sandwich composite as the research object,and the intermediate foam is PMI foam.Then multi-sandwich design is performed on the number of foam sandwiches.Each layer of panel and foam are stitched together as a whole using sutures.Vacuum-assisted resin molding transfer molding(RTM)is used to obtain standard impact test pieces.Non-destructive testing.The low-speed impact response of unstitched and stitched multilayer foam sandwich composites under 50 J impact energy was studied by a drop weight impact experiment,and its damage law was explored.The finite element software ABAQUS was used to establish a finite element model and carry out numerical simulations to analyze the effects of different stitching densities,impact energy and foam layers on the low-speed impact response of sandwich composites,and explore the mechanism of the effects of multilayer and stitching on low-speed impact properties of sandwich composites.Finally,the finite element model is compared with the load-time curve in the experiment to verify the validity and accuracy of the finite element model.The results show that the panel and foam have better deformation ability after being split into multiple layers,and can absorb more energy through deformation.The stitching can improve the strength and stiffness in the thickness direction of the material,and bind and bond the layers as a whole,while suppressing the occurrence and spread of cracks.Therefore,the multilayer foam sandwich composite has better low-speed impact performance,and the more the number of layers,the better the performance.Among them,the composite with a foam sandwich of three reduces the damage area by 14%,the damage depth is reduced by 34%,and the suture density is 5x5 mm.23% reduction and 53% reduction in damage depth.So stitching can further improve the low-speed impact properties of multilayer foam sandwich composites.Taking the simulation of a three-layer foam sandwich composite as an example,when the stitching density is 3x3 mm,the damage area is reduced by 46%,and the damage depth is reduced by 32%,and its impact resistance is further improved.This shows that as the stitching density increases and the number of interlayers increases.The impact resistance of the foam sandwich composite material is better.