Damage Analysis of CFRP Hybrid Bonded-Bolted Joint during Insertion of Interference-Fit Bolt

Abstract

In this study, experiments and finite element analysis (FEA) were used to evaluate the impact of interference-fit sizes on CFRP hybrid bonded-bolted (HBB) joint damage during bolt insertion. The specimens were designed in accordance with the ASTM D5961 standard and bolt insertion tests were performed at selected interference-fit sizes (0.4%, 0.6%, 0.8%, and 1%). Damage to composite laminates was predicted using the Shokrieh–Hashin criterion and Tan’s degradation rule via the user subroutine USDFLD, while damage to the adhesive layer was simulated by the Cohesive Zone Model (CZM). The corresponding bolt insertion tests were performed. The variation of insertion force with interference-fit size was discussed. The results showed that matrix compressive failure was the main failure mode. With the growth of the interference-fit size, more failure modes appeared, and the failure region expanded. Regarding the adhesive layer, it did not completely fail at the four interference-fit sizes. This paper will be helpful in designing composite joint structures and especially for understanding CFRP HBB joint damage and failure mechanisms.

Study on Bearing Strength and Failure Modes of Single Bolted Joint Carbon/Epoxy Composite Materials

“…For example, Guo qiang Gao et al used progressive damage modeling and simulations to forecast the strength of aircraft bolted joints in composite laminates, which improved design, analysis, and certification efficiency [ 22 ]. Long Yan et al investigated the influence of interference fit sizes on damage in CFRP hybrid bonded–bolted joints and discovered matrix compression failure as the most common failure mechanism [ 23 ]. Gang Liu et al created an asymptotic damage model to predict failure behavior in complicated composite laminated bolted joints and verified it with experimental results [ 24 ].…”

Mechanistic Study of Failure in CFRP Hybrid Bonded–Bolted Interference Connection Structures under Tensile Loading

“…Hu et al [30] established threedimensional failure criteria and exponential damage evolution criteria accounting for the influence of temperature effects, studying the damage interface and preload response under different levels of interference. Yan et al [31] conducted a study on the damage caused by bolts during the insertion process of hybrid bonded-bolted interference connections, but the influence of the damage generated after insertion on the structure's performance was not considered. Progressive damage in the adhesive layer generally corresponds to Mode I, Mode II, and mixed-mode (Mode III) fractures.…”