Numerical Simulation And Damage Detection Stitched Foam Core Sandwich Composites Under Low Velocity Impact

Stitched foam core sandwich structure composite compared to traditional materials of this structure,as the suture of the role of its comprehensive performance has been significantly enhanced,and the design of the material can be improved,which makes it in the aerospace,automotive,ship and other areas of the increasingly widespread application.For this kind of composite foam sandwich structure,such as light,sound insulation,heat insulation,high specific strength,and excellent impact resistance,which properties make it widely used in wall-like structures.And it is difficult to avoid the impact of the slab structure in the process of using the low-speed impact.Therefore,the research on the low-speed impact resistance of the sieved foam sandwich structure has high practicability.In this paper,we study the effects of stitched and unstitched foam sandwich composite materials on the low-speed impact resistance,and increase the research on the low-speed impact resistance of the impacted fiber panel sieved foam sandwich composites to further improve the impact resistance of the suture mechanism,the main research work is as follows:First of all,using VARTM process to complete the processing of composite materials,and using CNC waterjet cut into the appropriate size.The impact test of the impact energy 10 J and 20 J was carried out by means of instrumentation drop hammer impact test.The impact response of the three kinds of foam sandwich composites with stitching,non-stitching and panel stitching were analyzed and compared.Secondly,the damage of the three kinds of foam sandwich composites was tested by means of ultrasonic non-destructive testing,through the longitudinal contrast of different depth damage,the damage law of the three is summarized;and through the horizontal comparison of the damage between the three to assess their impact resistance of the pros and cons,and according to the impact of the experimental results to make the appropriate analysis.Finally,the ABAQUS finite element software is used to simulate the impact energy 10 J of the three above.The results of the simulated response are compared with the experimental results,and the results are compared with the results of the non-destructive testing.After confirming the validity of the finite element model,the impact properties of the above three kinds of foam sandwich composites under 10 J impact energy were studied and analyzed,and the delamination damage of the above three fiber panels is studied and compared.