Residual Strength Analysis Of Composite Structures Containing Delamination

Carbon fiber composite materials have been widely used in the aerospace field.Due to the weak interlaminar properties of composite laminates,interlaminar delamination is easy to occur,which reduces its compressive residual strength.In this paper,the effects of delamination size and position on the compressive residual strength of the structure are analyzed using a combination of experimental research and numerical simulation for composite laminates,stiffened plates,cylinders,and conical structures with delamination damage,the main contents are:1)Carry out the compressive residual strength test of composite laminates with delamination damage,and study the influence of the delamination size and position on the residual strength.2)Based on the ABAQUS,UMAT subroutine was wrote to introduce the Hashin failure criterion and Camanho degradation criterion to predict the fiber and matrix damage,using the cohesive zone model to predict the delamination expansion,comparing the residual strength of compression obtained from experiments and simulation and verifing the reliability of the simulation.3)Based on the ABAQUS,a stiffened plate model with debond was established,the effect of the position and size of debond on the compressive residual strength was studied.Simulation results show that: When the position of the debond is the same,the compressive residual strength decreases until it stabilizes as the size of the debond increases;when the size of the debond is the same,the closer the debond is to the potting area,the greater the compressive residual strength.4)Based on the ABAQUS,a curved plate,cylinder,and cone model with delamination damage was established.First,the effect of the curvature of the curved plate on the compressive residual strength was studied,then the influence of the size and position of the delamination on the compressive residual strength of the curved plate,cylinder and cone was studied.The simulation results show that the compressive residual strength of curved plate with larger radian is higher than that of plate,and the increase in delamination size and deeper position will reduce the compressive residual strength.For cylindrical and cone models,the compressive residual strength only increases with the deepening of the delamination position.