关键词: 导波, 铆钉连接, 长桁对接结构, 结构健康监测, 仿真方法

Abstract: Complex multi-rivet stringer splice joints are extensively employed in primary load-bearing components of modern aircraft, such as fuselages and wings, and their operational safety critically influences the reliability of the aircraft structure. During service, significant local stress concentrations arise due to geometric discontinuities, such as rivet holes and lap interfaces. Under alternating loads like flight cyclic loads, micro-fatigue cracks are prone to initiate at rivet hole edges and propagate along rivet rows, resulting in multiple-site damage. Guided wave monitoring is regarded as an effective approach for damage identification in such structures, owing to its sensitivity to minor defects and extensive coverage. However, nonlinear factors prevalent in stringer splice joints, including preload, frictional contact, and multi-interface coupling, complicate the propagation behavior of guided waves within the joint region. A systematic understanding of the underlying propagation mechanisms is still lacking. To address these issues, this paper proposes a finite element simulation method for guided wave propagation in complex multi-rivet stringer splice joints, based on a zoned bond–friction contact model. First, the distribution of contact stress on the joint interface under varying preloads is obtained through steady-state static analysis, revealing the non-uniform characteristics of contact pressure distribution induced by preload. Subsequently, the contact-affected zone formed by rivet clamping is determined using the half-apex angle theory of the joined parts. Combined with the interfacial contact pressure distribution, the joint interface is modeled in zones, divided into bonded contact and frictional contact regions, thereby establishing a composite bond–friction contact model to achieve accurate modeling of the complex joint interface. Finally, guided wave monitoring experiments are conducted to validate the simulation results, followed by a comparative analysis of multi-channel guided wave signals. The results demonstrate that the contact mechanical properties of the riveted joint region significantly influence guided wave propagation. The pro-posed simulation method provides theoretical and numerical support for guided wave modeling and structural health monitoring of complex jointed structures.

Key words: guided waves, riveted joints, stringer splice joint structure, structural health monitoring (SHM), simulation method