| The bonding strength analysis of composite structures plays an important role in the assessment ofthe structural integrity. The main objective of this thesis is to systematically summarize the main types,failure modes and the other typical problems during the bonded structure design. A modified model wasproposed in this thesis to analyze the structural strength and damage tolerance of bonded compositestructures.At first, the theoretical analysis and finite element analysis of bonding structure has been reviewedin this paper. The mechanics analysis model of bonding structure consist of the model based on finiteelement stress analysis, the model based on fracture mechanics and the model based on damagemechanics. The basic ideas of all the three models, scope of applications, advantages and weaknesses,improvement and expansion, construction of finite element mode were described and compared.Secondly, A quasi-three-dimensional nonlinear stress analytical solution of composite single-lapadhesive joints containing strip defects has been established on the previous work, Consideringboundary conditions such as the end lap area with adhesive shear stress to zero, the stress state at anypoint has been predicted by solving a series of first-order differential equations. The results have beencompared with those of finite element method and show that the results have good accuracy and awider scope of application.Third, the equivalent methods of defects embedded composite adhesive joints were summarized inthe paper. A finite element model was established to validate the feasibility of shape simplified methods.A three-dimensional method was proposed for estimating the residual strength, crack growth rate andmaximum damage tolerance of defective bonding joints by compression loads, using the Hashin failurecriteria and Camanho degraded criterion in the paper. The laminate compression failure of thesubroutine has been developed based on the UMAT in ABAQUS software. |
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