A dynamic installation method to improve the morphological characteristics of the bolt-hole contact interface in CFRP interference bolted structures

Dynamic installation (DI) of composite fasteners can reduce interface damage caused by interference and further improve joint performance. Understanding the low-damage mechanisms during DI based on electromagnetic force is critical. In this paper, a 3-D nonlinear progressive damage model based on continuum damage mechanics (CDM) was developed to predict the geometric dimensional variations of the bolt, the damage behavior and stress distribution of the bolt-hole contact interface after interference-fit connection. Static installation (SI) analysis was also considered as a comparative study. Experimental bolt-hole interface damage behavior validated the FEA results. The results show that DI can significantly reduce the installation resistance by thinning and elongating the bolt, so as to remarkably reduce or avoid severe damage to composite laminates, especially for large interference sizes. The low installation damage of the DI specimens results in more uniform residual stresses and higher amplitudes at the hole edges, which may be more conducive to achieving a more uniform stress distribution in the joints under external cyclic loading, thus helping to reduce the incidence of failure and extend the operating horizons of structures.

Automated summary

This paper presents a dynamic installation (DI) method based on electromagnetic force to reduce damage to composite laminates and improve joint performance. The study shows that DI can effectively decrease installation resistance, reduce severe damage to laminates, and improve stress distribution in the joint.