Transmission of Plate Flexural Waves through Reinforcing Beams

An infinite plate to which a narrow infinitely long beam is attached rigidly and continuously may be considered as an idealization of some typical flight vehicle structures. Reflection, transmission, and near‐field effects, associated with a straight‐crested flexural wave impinging on one side of the beam are presented as functions of the properties of the plate and beam and interpreted in terms of trace‐matching of the flexural waves in the plate with flexural and torsional waves in the beam. Upper bounds on the resulting dynamic strain concentration factors and implications pertaining to the design of beam‐reinforced panel structures with favorable fatigue properties are discussed. (Supported by Wright Air Development Division.)