Demountable interlocking connection with embedded plates for diaphragm systems: Effect of key parameters and design recommendations

Demountable connections play a crucial role in promoting the reuse of building structures, as individual components can be disassembled and reused at the end of their service life. An innovative demountable interlocking web connection that relies on neither traditional welding nor bolting methods, greatly improving assembly and disassembly efficiencies compared with traditional bolted connection, has been previously proposed and experimentally investigated. This paper presents a comprehensive finite element analysis to investigate the key parameters influencing the performance of the proposed demountable connection. A finite element model was first developed and validated against experimental test results, and subsequently parametric analyses including the faceplate tooth width, connector thickness, connector flange height and the faceplate material were carried out. The finite element analysis results revealed that the application of thicker connectors with identical shear capacity significantly relieved the local plasticisation of faceplate tooth by increasing the contact area, which is beneficial in improving the reusability of the connection. Furthermore, three distinct failure modes were observed: the shear failure of connectors, flexural failure of connector flanges, and the failure of faceplate teeth. To enable the reuse of floor slabs and fully utilise the shear capacity of the connectors, it is recommended that the connection should be designed to fail in shear failure of the connectors by increasing the tooth widths, upgrading the faceplate material, and enhancing the height of the connectors' flanges. Design equations were also proposed corresponding to these three failure modes.