Research On Damage Assessment And Repair Of Composite Sandwich Structure With Foam Core

Strength analysis and repair of composite structure are important parts of composite structuredesign. Composite sandwich structure with foam core is widely used. It is highly important andsignificant to carry out strength analysis, damage assessment and repair method research oncomposite sandwich structure with foam core.Composite sandwich panel with foam core is the research object in this paper. Finite elementincremental damage analysis of the sandwich panel scatheless and damaged is used in the strengthanalysis and failure process research under uniaxial compression load. Some Python programs arecompiled for parametric modeling, incremental damage analysis and stiffness reduction method.Consequently, the finite element incremental damage analysis can be carried out accurately andefficiently.Strength analysis of non-damaged composite sandwich panel with foam core adopts threestrength theories, such as Hill-Tsai, Hoffman and Tsai-Wu. The damage prediction results of the threestrength theories are similar. As Hill-Tsai strength theory is widely used, it is used in residual strengthanalysis of damaged and repaired composite sandwich panels with foam core.Patch repair, taper sanded repair and step sanded repair are used in repair of composite sandwichpanel with foam core. The diameters of the patches are2.5and3times of the diameter of damage area,and the thickness of the patches is0.4mm. The oblique angle of taper sanded repair is4.6°. There aretwo kinds of step sanded repair. One’s step length is3.33mm and its step height is0.2mm. The other’sstep length is15mm and its step height is0.4mm.Strength data of non-damaged and damaged composite sandwich panels with foam core areobtained by strength analyses. These data can be used for damage assessment. The strength analysesof repaired composite sandwich panels provide reference for repair scheme.