In our previous studies, seismic forces for secondary systems (SS) such as nonstructural components are investigated using light-weight bending-beam models with boundary condition (BC) of both pin-supported ends or of both fixed ends. In this paper, seismic forces for SS modeled as beams with another BC of one fixed end and the other pin-supported end are examined. Structural frames and SS are assumed to be linear. A modal analysis method for them is derived. The results with different BCs are compared and clarify the effect of BCs on seismic forces for SS.
