Toward Resilient Structural Walls Using Compliant Mechanisms: Numerical Feasibility Study

Self-centering walls have demonstrated superior performance, making them viable resilient structural systems capable of providing full operability during and after seismic events. These walls primarily rely on post-tensioning tendons to generate the necessary recentering forces. However, tendons can suffer from stress loss and anchorage failure, which may complicate the industrialization of self-centering wall systems. Therefore, this study aims to facilitate and accelerate the modular construction of self-centering walls by replacing tendons with compliant mechanisms designed to exhibit a bi-stiffness response. The compliant mechanisms were custom-designed using optimization techniques to exhibit compression-only bi-stiffness behavior, tailored for required capacities and stiffnesses that can be effectively utilized in the design of self-centering walls. This approach can offer a promising alternative to traditional tendon-based systems. To evaluate the feasibility of using the designed mechanisms to achieve the bi-stiffness response for a structural wall, a self-centering wall benchmark was selected. Using the tested wall configuration, the designed compliant mechanisms were positioned at the right and left toes of the wall panel to operate in a complementary manner, providing the bi-stiffness response as the panel was pushed back and forth. The results indicated that the designed mechanisms, although functioning in a compression-only manner, could approximately achieve similar capacity and stiffness as those of the benchmark. The implementation of these novel compliant mechanisms could lead to more efficient and reliable construction practices for earthquake-resistant structures. This not only challenges the current reliance on tendons but also paves the way for replacing conventional shear walls with self-centering walls.