Guides “bimorphes” d''ondes ultrasoniques “bimorph” ultrasonic wave guides”

An analysis of the dispersion of elastic waves is presented for two types of long ultrasonics wave-guides that we qualify of “bimorph”: (i) a “three-layer” guide made of two different materials and (ii) a “clad core” guide built up of a rectangular core surrounded by a cladding, the materials of the rod and cladding having different properties. An analytical model is proposed to describe the extensional, flexural and torsional motions in “bimorph” wave guides having two geometrical and material symmetry axes. The asymptotic behaviour of the model allows one to select the material properties which lead to modes guided essentially either in the central layer or in the core of the bimorph guide. Moreover, the dispersive properties of a “bimorph” can be controlled through the choice of geometrical and material parameters.     

„Ideale“ Lötverbindung und „optimale“ Lötverbindung

If due to the market analysis a company makes the decision for the production of a new product by application of soldering and special the soldering with temporarily liquid solder, this one is then made specifically after that the company specific construction and production preparation. Either the decision for soldering is technically and/or economically well‐founded or she is even unavoidable by so‐called mixed material connections in the assemblies. This hybrid design finds application increasing today. In the contribution on hand the analysis and assessment of the soldering theory and practice is carried out under the point of view of the possible production of “ideal soldered connections” and “optimal soldered connections”.