The transmission law of flexural waves through L-shaped joints connected by two plates made of two different materials is studied by using the wave approach. The numerical simulation of transmission parameters of the steel-aluminum joint is carried out synchronously with MATLAB. The transmission law of flexural waves through Lshaped joints with different materials is compared with that of homogeneous material joints, which shows that there are some prominent differences between them. One of the most remarkable divergences is that the thickness ratio corresponding to the minimum transmission loss is not the same. The result of this paper is of important guiding significance for acoustic design and vibration wave impedance control of hybrid structure, especially for vessels with steelaluminum mixed structure.
Except of being absorbed due to the damping loss, the elastic waves also undergo the loss, reflection, transmission, and wave conversion in the joints meanwhile. Cremer et al. (1988) analyzed both longitudinal and flexural waves transmission at normal incidence for different junctions, as well as flexural waves transmission for oblique incidence at a corner junction by wave approach. Budrin and Nikiforov (1964) used the line joint model to represent a junction by wave approach. Kihlman (1967) calculated the flexural wave transmission at symmetric cross junctions for the case of random incidence. Langley and Heron (1990) discussed the elastic wave transmission through plate/beam junctions. A generic plate/beam junction was considered. The junction consisted of an arbitrary of number plates which were either coupled through a beam or directly coupled along a line. Mccollum and Cuschieri (1990) calculated the power transmission at an L-shaped junction including both the effects of in-plane waves and rotary inertia and shear (Mindlin bending) in the plates. These references are cited only as examples, because there are numerous other works using this method (Che, 2008).
