Ju Young-Hun, Mansouri Iman, Hu Jong-Wan
Department of Civil and Environmental Engineering, Incheon National University, Incheon 22012, Korea.
Incheon Disaster Prevention Research Center, Incheon National University, Incheon 22012, Korea.
Materials (Basel). 2022 May 13;15(10):3514. doi: 10.3390/ma15103514.
Traditional seismic design has a limitation in that its performance is reduced by significant permanent deformation after plastic behavior under an external load. The recentering characteristics of smart materials are considered to be a means to supplement the limitations of conventional seismic design. In general, the recentering characteristics of smart materials are determined by their physical properties, whereas polyurethane springs can regulate the recentering characteristics by controlling the precompression strain. Therefore, in this study, 160 polyurethane spring specimens were fabricated with compressive stiffness, specimen size, and precompression strain as design variables. The compression behavior and precompression behavior were studied by performing cyclic loading tests on a polyurethane spring. The maximum stress and maximum strain of the polyurethane spring showed a linear relationship. Precompression and recentering forces have an almost perfect linear relationship, and the optimal level of precompression at which residual strain does not occur was derived through regression analysis. Additionally, a prediction model for predicting recentering force based on the linear relationship between precompression and recentering force was presented.
传统抗震设计存在局限性，即在外荷载作用下发生塑性行为后，其性能会因显著的永久变形而降低。智能材料的自复位特性被认为是弥补传统抗震设计局限性的一种手段。一般来说，智能材料的自复位特性由其物理性能决定，而聚氨酯弹簧可以通过控制预压缩应变来调节自复位特性。因此，在本研究中，以抗压刚度、试件尺寸和预压缩应变为设计变量，制作了160个聚氨酯弹簧试件。通过对聚氨酯弹簧进行循环加载试验，研究了其压缩行为和预压缩行为。聚氨酯弹簧的最大应力和最大应变呈线性关系。预压缩力和自复位力几乎呈完美的线性关系，通过回归分析得出了不产生残余应变的最佳预压缩水平。此外，还基于预压缩力和自复位力之间的线性关系，提出了一种预测自复位力的预测模型。
