The effect of column mass on shear building vibrations

In the usual assignment of mass for shear building models, the mass of the columns is lumped with the mass of the floor at each floor level. In order to account for frequencies of modes higher than N in an N-storey building, however, additional column masses must be identified. In this note, such additional masses are located at the mid-height of each column, and the characteristics of the shapes and frequencies of the resulting higher mode set are investigated.