Research On Compression Buckling And Post-Buckling Behavior Of J-Type Composite Stiffened Plate

Composite stiffened plate is an important structure of aviation aircraft.It has many advantages such as high carrying efficiency and simple forming process.In the design of new UAVs,weight index is one of the key considerations.The weight advantage of composite material itself has been It is difficult to meet the design requirements,and after the stiffened plate buckles,it can still continue to carry the load.In-depth exploration of the stiffened plate’s load-bearing potential provides a new idea for the lightweight of the UAV.In the actual working conditions of the stiffened plate,it may be subject to different positions and different degrees of impact.Whether the stiffened plate can continue to be used depends on the impact damage on the buckling and post-buckling behavior of the stiffened plate.At present,there are few studies on impact-damaged stiffened plates.In this paper,test methods and finite element simulation are used to analyze the compression buckling and post-buckling of intact stiffened plates and impact-damaged stiffened plates,and parametric research on stiffened plates.The main contents of the research are as follows:The research object is the J-type composite stiffened plate,a feasible test plan is formulated,the fixture is designed and manufactured,the compression test is performed on the stiffened plate,the failure process of the stiffened plate is analyzed in detail,and the load-bearing characteristics of the stiffened plate after buckling are studied,the buckling load and ultimate load of the stiffened plate are obtained;the finite element model of the stiffened plate is established in ABAQUS,obtain buckling load and buckling mode through buckling analysis,introduce initial geometric defects,and then perform post-buckling analysis on the stiffened plate,detailed simulation of the damage and failure process of the ribs,skin and glue layer,and obtain the ultimate load of the stiffened plate,the finite element simulation results are compared with the test results to verify the reliability of the finite element simulation simulation.The impact test was carried out on the center of the skin and the back of the ribs of the composite stiffened plates,the impact damage was analyzed by visual observation and non-destructive testing,and the compression test of the stiffened plates after impact was carried out to analyze the failure process of the stiffened plates;the finite element simulation of the compression test of the stiffened plate impacting the center of the skin,the impact damage is simplified into a circle through the softening inclusion method,the finite element model of the stiffened plate is established,and the buckling and post-buckling analysis of the stiffened plate is performed to verify The feasibility of the research method;study the impact of different degrees of impact damage in the center of the skin on the buckling and post-buckling behavior of stiffened plates.Finally,the influence of the glue layer,laying method of ribs and skin,geometry size of ribs on the buckling and post-buckling bearing capacity of the stiffened plate are studied.Reasonable suggestions for increasing the buckling load,ultimate load and material utilization of stiffened plates are given.