Experimental and numerical studies of miniature bar-typed structural fuses with Teflon pads

Many studies have proved that structural fuses could improve the seismic performance of structures efficiently. A structural fuse named the miniature bar-typed structural fuse (MBSF) has been proposed and investigated by the authors, which consists of a central core bar, a confining tube. To further improve the mechanic performances of the MBSFs under compressive loadings, Teflon pads are introduced to adjust the contact and friction status between the core bar and the confining tube. Three groups of specimens were discussed including the specimen with a single cutting line (SC), the specimen with double cutting lines (DC), and the specimen with triple cutting lines (TC). The results show that the hysteretic performances of the fuses are improved with the help of Teflon pads. The compression strength adjustment factor declines when Teflon pads are appended. Numerical and theoretical analyses are also conducted which expounded the effect of the Teflon pads. Different plastic buckling deformation principles of the core bars are compared by the theoretical analysis. It is shown that Shanley's theory fits the numerical results well, which is recommended for the theoretical calculation of the proposed MBSFs.