Assessment And Analysis Of Repairs To Composite Stiffened Panels

Composite stiffened plate panels inevitably contain defects and develop damage in the manufacturing process and in daily service,which threatens the integrity and safety of the whole structure.Among the various repair methods,the mechanical repair has the advantage of low demand for equipment,simple operation and reliable performance,making it suitable for the out-field usage.In this thesis,the failure mechanisms of composite stiffened plates with delamination in the flange or skin,or impact damage in the skin are analyzed,and the corresponding mechanical repair methods are evaluated.The main contents include:(1)Experimental study on damaged and repaired composite stiffened plates is carried out.By comparing the buckling loads,ultimate loads and failure modes of intact specimens,damaged specimens and repaired specimens,the effects of damage modes on structurals stability,load-bearing capacity and repair effectiveness are analyzed.(2)The progressive damage analysis method based on the finite analysis method is used to analyze the failure of three kinds of damage test pieces and repair test pieces.By comparing the numerical simulation results with the experimental results,the damage propagation process is presented in detail and the suppression of the repair scheme on the damage is evaluated.(3)The numerical model is used to conduct parametric analysis on the delamination in the skin and flange,the influence of damage parameters on the structural stability is studied,which provides references for the repair design of damaged structures.