Shake table tests on timber frame structure infilled with dry bond masonry

Abstract

This study presents the results of a series of half-scale shake table experiments conducted on a single-room; single-story timber frame filled with dry-bonded brick masonry. Two half-scale models, one without infill and one infilled with dry bond brick masonry, were fabricated and tested on a shaking table to examine the seismic performance of timber-framed masonry structural systems. For dynamic characterization, both models were subjected to white noise base excitation, and to investigate the seismic behaviour, the models were subjected to incrementally increasing ground motion in accordance with single ground motion record incremental dynamic analysis. The dynamic characteristics, such as natural frequencies, damping, mode shapes, and stiffness degradation, were evaluated. The stiffness degraded to 43% in the model infilled with bricks and 62% in the model without infill. The peak acceleration and displacement responses and the global hysteresis response were assessed and evaluated. While determining the acceleration profiles of the model, the maximum out-of-plane acceleration recorded was of the order of 1.1 g for the model without infill and 1.6 g for the model with infill. The acceleration response was more amplified for models with brick infill, while a lower value was observed in models without infill. Based on the fact that the structure was linear even at maximum acceleration amplification during the test, it can be inferred that the timber-framed structure possesses a high degree of flexibility and deformability, and also that the energy dissipation capacity of the structure increased with the increase in peak ground acceleration of the input ground motion.