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Appraising Repair Tolerance Of Damaged Honeycomb Sandwich Structure

Posted on:2019-04-17Degree:MasterType:Thesis
Country:ChinaCandidate:Y ZhangFull Text:PDF
GTID:2322330569488259Subject:Aeronautical Engineering
Abstract/Summary:PDF Full Text Request
Due to various merits,Honeycomb sandwich structure is widely used in aerospace field.In recent years,this structure has been increasingly applied on aircraft,especially civil aircraft.However,a series of inherent factors,such as the anisotropy of composite materials and non-uniform wall thickness of honeycomb core,make it difficult to ascertain damage-related repair tolerance.Advanced foreign aircraft manufacturers have specified data in the maintenance manuals,but the method for giving the repair tolerance is rarely found in detail.After confirming the usage of composite honeycomb sandwich structure on two widely used aircraft models,in accordance with their Structure Repair Manual(SRM),the values of repair tolerance of some structural members are analyzed,and the detailed evaluating method for honeycomb sandwich structure is explored.The main work includes:1.According to SRMs,the honeycomb sandwich structure members on A320 are contrasted with those on B737 series aircraft.The characteristics,allowable damage and repair tolerance of honeycomb sandwich materials of similar areas of typical structures on both aircraft are compared,and the dimensionless allowable damage and repair tolerance are analyzed.2.According to definitions of crack,dent and delamination prescribed in SRM,the real spoiler structure is taken as an instance.The sandwich laminate models of the spoiler with three types of damage,as well as a model without any damage are established respectively via Patran.The relationship between the allowable damage,residual strength and the shape and size of damage are studied by buckling analysis.The residual strengths of three damaged models are studied.The results are congruous with the manual prescription,which verifies the reliability of theoretical analysis.The results demonstrated in the thesis can be referred to determine the repair tolerance of similar structures on large aircraft in China.Meanwhile,the theoretical research provides an accessible analytical method to calculating repair tolerance of various composite structure on domestic aircraft.
Keywords/Search Tags:Honeycomb sandwich structure, Repair tolerance, Buckling, Composite
PDF Full Text Request
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