Interior Receptances of Beams

The usefulness of the receptances of beams has been demonstrated elsewhere; they permit, for instance, the calculation of natural frequencies of rigid-jointed frames from standard tables by simple routine methods of arithmetic. For many purposes it is convenient, if not essential, to use the receptances in closed (as opposed to series-) form. Tables of receptances in closed form have been confined to those measured at and between the ends of beams or between the ends and interior points along the length. A knowledge of receptances measured at and between interior points, however, may shorten calculations considerably. A method is explained for finding these quantities and tables of results are presented for uniform beams. Experimentally determined results confirmed the accuracy which was easily obtainable with the data presented.