Research on Pin-load Distribution for Countersunk Joint Considering Accumulated Damage of Composite Laminates

Abstract

Abstract The paper presents a numerical simulation about the damage process of the multiple countersunk bolted double-lap joints based on the cumulative damage theory which is widely used to estimate the mechanical strength of fastener joints, the Hashin’s failure criterion, and the Tan’s stiffness degradation model, and investigates the influence of the composite materials cumulative damage on the pin-load distribution. The numerical model of composite joints has been established in the commercial finite element software ANSYS to research the influence of the composite cumulative damage on the pin-load distribution, to assess the feasibility of integral analysis as well as to evaluate the error and rationality of traditional methods by applying the global analysis technology. The conclusions demonstrate that the results obtained with the method of composite cumulative damage considering properties degradation are close to those of conventional methods. The pin-load distribution is characterized by “Bolts at both ends bearing greater load, the central bolts bearing smaller load” during the whole loading process. Using conventional methods to study the pin-load distribution is easy and efficient to meet the needs of engineering application.