A Study On The Failure Mode Of Stiffened Panels With Pitting Corrosion

The hull stiffened panel is a thin-walled composite structure,which is prone to buckling failure.The corrosion of the components by the external environment further increases the probability of buckling.It is of great significance to establish an accurate and effective method for evaluating the ultimate strength of stiffened panels with corrosion damage.There are many failure modes in the buckling of stiffened panels,which will severely affect the ultimate bearing capacity of stiffened panels.In order to accurately evaluate the ultimate strength,it is necessary to consider the effect of failure modes.This paper establishes a method for evaluating the ultimate strength of corroded stiffened panels based on failure modes.The main study contents are as follows:(1)On the basis of theoretical analysis,the occurrence mechanism,mechanical parameters and identification methods of beam-column buckling,local plate buckling,stiffener web buckling and stiffener tripping are determined.The controlled variable method is adopted to comprehensively study the influencing factors and evolution laws among local plate buckling,stiffener tripping and beam-column bulkling.(2)According to the trend of the ultimate strength and the state of stress and deformation,the critical points when the failure mode changes are determined,and a evaluation strategy based on continuous boundaries is proposed to determine which failure mode plays a major role in the buckling failure.In addition,based on the results of different failure modes,a highly applicable formula for evaluating the ultimate strength of stiffened panels is obtained by fitting.(3)The influence of corrosion volume on the ultimate strength and failure modes of stiffened panels is explored.The equivalent ultimate strength evaluation formulas of pitting stiffened panels suitable for different failure modes are proposed.A procedure for evaluating the buckling ability of corroded hull stiffened panels is compiled to conveniently realize the evaluation of failure modes and ultimate strength.Based on the above work,it is known that the failure modes of stiffened panels is closely related to specific mechanical parameters and corrosion parameters,and cannot be ignored in the evaluation of ultimate bearing capacity.After comparison and demonstration,the ultimate strength evaluation method of corroded stiffened panels based on failure modes proposed in this paper is accurate and reliable,and has certain reference value.