Figure 1
Different tested configurations of supplemental damping in wood-framed shear walls from
Ugalde et al. 2019Ugalde, D., Almazán, J. L., Santa María, H., & Guindos, P. (2019). Seismic protection technologies for timber structures: a review. European journal of wood and wood products, 77(2), 173-194.: (a)
Filiatrault (1990Filiatrault A (1990) Analytical predictions of the seismic response of friction damped timber shear walls. Earthq Eng Struct Dyn. 19, 259-273. https://doi.org/10.1002/eqe.4290190209.
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Dinehart et al. (1999Dinehart DW, Shenton HW, Elliott TE (1999) The dynamic response of wood-frame shear walls with viscoelastic dampers. Earthq Spectra. 15, 67-86. https ://doi.org/10.1193/1.15860 29.
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Higgins (2001Higgins C (2001) Hysteretic dampers for wood frame shear walls. In: 2001 Structures congress and exposition, ASCE. D.C., USA.), (g)
Symans et al. (2002aSymans MD, Cofer WF, Du Y, Fridley KJ (2002a) Evaluation of fluid dampers for seismic energy dissipation of woodframe structures. California Institute of Technology and the Consortium of Universities for Research in Earthquake Engineering, Richmond), (h)
Dutil and Symans (2004Dutil DA, Symans MD (2004) Experimental investigation of seismic behavior of light-framed wood shear walls with supplemental energy dissipation. In: 13th World Conference on earthquake engineering. Vancouver, Canada, p 15), (i)
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Kasai et al. (2005Kasai K, Sakata H, Wada A, Miyashita T (2005) Dynamic behavior of a wood frame with shear link passive control mechanism involving K-brace. J Struct Constr Eng 70:51-59).
Figure 2
Wood-frame shear wall configurations with energy dissipators reported by Shinde and Symans (2010Shinde, J.K., Symans, M.D., (2010). Integration of seismic protection systems in performance-based seismic design of woodframed structures. Technical Report MCEER-10-0003.): (a) chevron-brace design, and (b) toggle-brace design.
Figure 3
Schematic representation of some of the available amplification mechanisms (AM) from Baquero et al. (2016Baquero, J.S., Almazán, J.L., Tapia, N., (2016). Amplification system for concentrated and distributed energy dissipation devices. Earthquake Engineering & Structural Dynamics 45: 935-956.).
Figure 4
Conventional wood-frame shear wall designed for an anchorage type Anchor Tie-Down System.
Figure 5
Eccentric Lever-Arm System (ELAS): (a) one damper (concentrated energy dissipation); and (b) deformed position.
Figure 6
Wood-frame shear wall with a double ELAS mechanism.
Figure 7
Details of the ELAS mechanism and nomenclature of its components.
Figure 8
UFP dissipator from Arizaga and Almazán (2019Arizaga, R., and Almazán, J.L., (2019). Estudio experimental de disipadores de energía flexurales UFP con restricción interna e implementación numérica. Tesis Pontificia Universidad Católica de Chile, Santiago, Chile.): (a) geometric variables of the flexural plates, (b) internal restraint system (IRS).
Figure 9
Lateral view of the UFP specimens with and without IRS tested by Arizaga and Almazán (2019Arizaga, R., and Almazán, J.L., (2019). Estudio experimental de disipadores de energía flexurales UFP con restricción interna e implementación numérica. Tesis Pontificia Universidad Católica de Chile, Santiago, Chile.).
Figure 10
Comparison between load-displacement responses of the UFP devices with and without the IRS.
Figure 11
(a) ELAS free-body diagram, and (b) amplified displacement at the end of the lever.
Figure 12
Wall-ELAS connection detail: Upper joint between the central stud, lever, and the floor beam.
Figure 13
Wall-ELAS connection detail: joint between the diagonal bar with the central stud and the floor beam.
Figure 14
Conventional wood-frame shear wall with double ELAS mechanism prior to the experimental test and the incorporation of the dampers.
Figure 15
Details of the UFP + IRS damper and its connection to the sole plates and studs of the shear wall.
Figure 16
Details of the UFP+IRS damper adapted to connect to the lever arm of the ELAS mechanism (the top restraining plate and its mounting elements are not shown for simplicity).
Figure 17
Details of the connection between the UFP+IRS damper and the lever arm of the ELAS amplification mechanism.
Figure 18
Test setup of the shear wall specimen before installing the double ELAS mechanism, dampers, and instrumentation (the blue frame shown in the picture is not part of the test setup).
Figure 19
Elevation view of shear wall specimen with its instrumentation.
Figure 20
Cyclic testing protocols for phase 1 y 2 (Left), and phase 3 y 4 (Right).
Figure 21
Reinforcement and stiffening of the upper connection between the central stud and floor beam.
Figure 22
Reinforcement and stiffening of the connection between the steel plate of the diagonal bar union and the bottom plate.
Figure 23
Relative displacements measured by transducers located in channels C9 to C12 during test phase 3.
Figure 24
Comparison of the shear wall cyclic response between the different phases, including a comparison of the undamped performance of the wall before and after a major earthquake (left above); comparison of the damped wall pre and post-earthquake (right above); comparison of undamped vs. damped wall before (left below) and after an earthquake (right below).
Figure 25
Energy dissipated by the sherar wall in each test phase for a lateral displacement equal to 61 mm.
Figure 26
Displacement amplification at the end of the lever arm of the ELAS mechanism compared to the overall lateral displacement at the top of the shear wall (phase 3).
Figure 27
Plastic deformations at the connections of the amplification system due to design flaws.
Figure 28
Synthetic ground motion record compatible with NCh2745 code elastic design spectrum (Zone 3 - Soil Type II).
Figure 29
Lateral drift comparison for the 6-story wood-frame vertical plane with and without the AASD system.
Figure 30
Energy analysis for the 6-story wood-frame vertical plane under investigation.
Table 1
Geometric characteristics of UFP tested by Arizaga and Almazán (2019Arizaga, R., and Almazán, J.L., (2019). Estudio experimental de disipadores de energía flexurales UFP con restricción interna e implementación numérica. Tesis Pontificia Universidad Católica de Chile, Santiago, Chile.).
Table 2
Schedule of testing phases and test specimen configurations.
Table 3
Test phase comparisons (at a 61 mm displacement amplitude).
Table 4
Geometry and mechanical properties of the shear wall components.