Bearing Failure of Bolted Composite Joints. Part II: Model and Verification

Abstract

An investigation was performed to study the bearing failure and response of a mechanically fastened laminated composite joint. The experimental work of the study was presented in Part I, and this paper summarizes the analytical work. An accumulative damage model based on the damage mechanisms observed from the experimental study was developed to simulate the bearing failure in the laminated composite joints. The model consists of two parts: damage prediction and constitutive modeling. Damage accumulation criteria by modifying Hashin criteria were proposed to predict the mode and extent of bearing damage as a function of the stress state, and the relationships between material properties and bearing damage were established based on failure mechanisms. A nonlinear finite element analysis based on the model was developed. Data obtained from this study and existing literature were used to validate the model. Overall, the predictions agreed with the data very well.

Effect of secondary bending on strength prediction of composite, single shear lap joints

“…HashinÕs criteria [18] differs from the quadratic criteria in that it is able to distinguish between different micro mechanical failure modes. It was combined with material property degradation rules [19][20][21][22][23] which allowed for prediction of damage progression, from damage-onset to final failure.…”

“…Parameters related to the fastener system include bolt type, bolt-hole clearance and lateral clamping force, which have been studied by several researchers [1,4,15,16,19,20,24,[26][27][28]. Countersunk fasteners provide less bearing strength [27,29,30] than protruding head fasteners due to the reduced length of the cylindrical bolt shank.…”

Bearing strength and failure behavior of bolted composite joints (part II: modeling and simulation)

“…Several analytical models have already been developed and documented in [2][3][4][5][6]. The progressive damage model revealed that the description of the material degradation due to damage is critical for the stress redistribution analysis.…”

“…In practice, experimental observation [7] has indicated that bearing failure and the response of bolted composite joints are strongly affected by the lateral constraints, and these conditions tend to prevent the reduction of laminate in-plane stiffness. Hung and Chang [4] damage accumulation model that took into account the effects of clamping pressure and lateral constraints on the bolted joints. However, since the determination of the critical bearing damage area was not fully clarified, further modifications to the material degradation rule will be necessary.…”

Mechanical Properties of Lab Joint Composite Structure of Glass Fiber Reinforced Polymers

“…Their results were in good agreement with the experimental data. Hung and Chang [7] extracted a two-dimension accumulation damage model to study effect of clamping pressure and lateral constraint on composite bolted joint.…”