🔹 Dynamic Properties and Seismic Performances of 1.5-Layer Space Frames with Lap-Units with Considering Vibration of Lower Joints
Published:
Jin, J., Chen, P. S., Liu, B., & Yan, X. (AICCE, 2022).
A new structural system called 1.5-layer space frame is proposed as the third member of the family of space frames, which may provide new design possibilities. The 1.5-layer space frames with lap-units are susceptible to deformation due to key part rotation about the axis of its upper chords. Therefore, it is necessary to capture the dynamic behaviors of the lower joints of the lap-units. Considering the vibration of lower joints, the main dynamic properties of four typical structures, including natural frequency and vibration mode shape are first examined, and the seismic performances are then assessed within the linear elastic range under selected earthquake excitations. To provide helpful information for practical design, the investigation on the relationship between structural properties and geometrical/design parameters is also conducted. As a result, the seismic response of the structures is significant when the depth-grid ratio (the ratio of web member and upper chord length) is greater than 0.5.