This paper explores the possibility of using flexible adhesives to dissipate energy in CLT buildings during earthquakes. In the first series of tests, a rod glued in a CLT panel with flexible adhesive was investigated. The connection was tested in pull-pull configuration using cyclic, tension-only loading. Different rod diameters and different thicknesses of the glue layer were tested. The tests have shown that the adhesive can resist large deformations and exhibits fairly large energy dissipation capacity. Based on the test results the numerical analyses were performed to test the behaviour of the connection when applied in CLT buildings. Existing constitutive models available in OpenSees software were used to simulate the specific hysteretic behaviour of the connection. The results have shown that the CLT wall anchored with "flexible" glued-in rods would have a significant energy dissipation capacity if a sufficient number of them were used as the hold-down devices. Such system could be used to dissipate energy in seismic areas.
This study investigates timber connections with flexible polyurethane adhesives, which prove to have the potential for timber-adhesive composite structures without mechanical connections for seismic regions. Results of conducted cyclic double lap-shear adhesive timber joints tests were compared with available experimental results on timber connections with standard mechanical dowel-type fasteners and with results of numerical finite element analysis. The study found that the shear strength, elastic stiffness and strength degradation capacity of the flexible adhesive connections were significantly higher compared to mechanical fasteners commonly used in seismic-resistant timber connections. The latter, however, manifested larger ultimate displacements but also yielded at lower displacements.
