The Effects Of Delamination Deficiencies On Compressive Mechanical Properties Of Reinforced Composite Skin Structures

With the main characteristics of high axial bearing capacity,strong antiinstability ability,high specific stiffness and strength,and open space structure,reinforced composite skin structures have broad application prospects.Delamination deficiencies often occur in reinforced composite skin structures.The existence of delamination deficiencies reduces the compressive strength and stiffness of the structure,affects the integrity of the structure,and leads to the weakening of the bearing capacity of the structure in service.Which greatly limits the application of reinforced composite skin structures.Therefore,it is necessary to analyze the influence of delamination deficiencies on the loadcarrying capacity and failure process of reinforced composite skin structures,so as to promote the application of reinforced composite skin structures.In this paper,the distribution of delamination deficiencies is designed according to the actual situation of delamination defects in reinforced composite skin structures.Axial compression tests were carried out on specimens with preset delamination deficiencies to observe the effects of different delamination deficiencies on the compressive bearing capacity,delamination deficiencies expansion and structural failure modes of reinforced composite skin structures.On the basis of the axial compression test,the reinforced composite skin structure model with delamination deficiencies is further developed by using commercial finite element analysis software ABAQUS.Progressive Failure Model is used to calculation,and the failure process of the structure is simulated based on hashin failure criterion and cohesive zoon.By summarizing and analyzing the experimental and simulation results,the effects of different types of delamination deficiencies on the bearing capacity,delamination expansion andfailure modes of reinforced composite skin structures are investigated in detail.Combining the results of experiment and simulation,it can be known that:The existence of delamination deficiencies in the skin and the interface between the skin and the stiffener reduces the compressive bearing capacity of the structure.The degree of reduction is proportional to the area of delamination defect and related to the specific location of delamination deficiencies.Overall,the influence of the delamination deficiencies in the interface between the skin and the longitudinal stiffener on the bearing capacity of the structure is the most obvious.The influence of delamination deficiencies on the failure mode of structure is not obvious.