Seismic damage mitigation for ceiling runner joints using spring assembly: Experimental and multi-scale numerical investigation

The seismic resilience of buildings is closely related to the seismic performance of non-structural systems. The vulnerability of suspended non-structural components is significant, with ceiling joints identified as the weakest seismic link in suspended ceiling structures. This paper proposes a simple and easily adaptable low-damage joint configuration for the main-cross runner joint and main-main runner joint in ceilings. These joints provide additional elastic re-centering stiffness and load-bearing capacity by incorporating pre-tensioned springs around the conventional joints, thus reducing the seismic damage to ceiling runner joints. The axial cyclic loading tests were conducted on the main-cross runner joints and main-main runner joints to compare the hysteretic behavior of the conventional and low-damage configurations. The influence of the attached springs on the damage patterns, peak load-bearing capacity, deformation capacity, and other characteristics of ceiling joints under axial load were analyzed. The experimental results show that the primary failure mode of the conventional main-cross runner joint and main-main runner splice joint is pullout failure at the latch region. In contrast, the low-damage joints, with the contribution of the re-centering spring's elastic recovery capacity, provide additional residual stiffness and load-bearing capacity after the failure at the runner ends, thereby pulling the runner back to its original position. Based on this, component-level numerical models were developed to characterize the force characteristics of the low-damage main-cross runner joint and main-main runner joint, and the time-history analysis on a validated system-level ceiling model demonstrates significant damage mitigation in the ceiling runner joints by using the proposed low-damage joint configurations. • Simple and adaptable low-damage joint designs for main-cross and main-main runner connections are proposed. • Axial cyclic tests compared conventional and low-damage ceiling joints' hysteretic behavior. • Component-level numerical models to characterize low-damage joint force characteristics are developed. • Time-history analysis of a validated system-level ceiling model proves low-damage joints significantly mitigate damage.