Test of Novel Self-Centering Energy Dissipative Braces with Pre-Pressed Disc Springs and U-Shaped Steel Plates

To control the residual displacement of the structure after strong earthquakes, this paper develops and validates a novel brace, i.e. the self-centering energy dissipative brace with pre-pressed disc springs and U-shaped steel plates (SCEDB-U). The pre-pressed disc springs are used for recovering nonlinear deformation and the U-shaped steel plates are used for dissipating energy. Initially, the configuration and working principle are described in detail. Then the analytical equations governing the cyclic behavior of the brace are derived. To confirm the concept, the large-scale bracing specimens are designed and manufactured for the quasi-static cyclic loading tests. In the tests, the varied parameters included the plate width of the U-shaped steel plates and the pre-pressure magnitude of the stacked disc springs. Besides, the high-fidelity three-dimensional finite element (FE) models of SCEDB-U are established. According to the experimental data, the SCEDB-U has typical flag-shaped hysteresis, which is characterized by excellent self-centering capability and stable energy dissipation ability. It also indicates that increasing the plate width of U-shaped steel plates can effectively improve the energy dissipation capacity, but may induce residual displacement; increasing the pre-pressure magnitude of disc springs could improve self-centering ability. The numerical results are in good agreement with the experimental data; hence, the FE models can be further utilized for parametric analysis, initial design and optimization.