The Adhesively Bonded Assembling Research On All-composite Light Aircraft Wings

With the development of aviation technology，more and more composite material hasbeen used in the structure of aircraft. There are three ways in the connection: adhesivebonding, mechanical connection and mixed connection. Compared with isotropic metalmaterials, cutting and machining operation can damage and weaken anisotropic compositematerial seriously and the interlaminar shear become more sensitive. Therefore, adhesivelybonding has been widely used in the design and aseembling of advanced composite structure.According to related record, More than half of failure phenomenons occur in the joints ofcomposite instructure. So it is necessary to study the influencing factors of adhesivelybonding for productive practice.This article analyses some problems of a domestic all-composite light aircraft. Theseproblems include big assembling clearance in the cementing and assemblying process,abnormal sound when the composite light aircraft wings withstanding maximum aerodynamicload and so on.The content of tolerance analysis is studying the impact that links have on the closedloop. Monte Carlo method as a statistical test methods is the most widely used in all kinds oftrials.In the paper, by studying tolerance analysis plan in the cementing and assemblyingprocess of all-composite light aircraft wings, a good tolerance analysis program is wrotebased on Monte Carlo by Matlab software. The program is good for control weight of lightaircraft through controlling the precision of parts.The finite element analytical methods is used to study the stress distribution of thecomposite light aircraft wings with maximum aerodynamic load. According to failure criteria,the conclusion that insufficient bonding area of ribs and webs bonded joints is drawn. Basedon the analysis of Joint strength and reliability, we improve the joints design.At the same time,Confirmatory tests on the modified adhesive joints is carried out to verify the feasibility.Anumber of specimens are made. We observe the way of destruction and obtain the corresponding data through a preliminary test. The analysis are verified by test.