The bending wave transmission between semi-infinite thin plates connected by a hinge or by an elastic interlayer is analyzed. The wave transmission across the interlayer is calculated analytically; the stiffening effect of the interlayer is simulated with a finite element model. The calculation results for the bending wave transmission demonstrate the importance of an offset mounting of a plate, and of the modulus of elasticity, the Poisson ratio, the loss factor and the shape of the interlayer. Theoretical predictions are compared with experimental results for a hinge and for different elastic interlayers in a T-junction.