A Timber-steel Buckling Restrained Brace for Multi-storey Framed Timber Structures

Download or read book A Timber-steel Buckling Restrained Brace for Multi-storey Framed Timber Structures written by Yue Xiao and published by . This book was released on 2019 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of earthquakes occurred in Christchurch that demonstrate the need for developing low damage economic multi-storey structures. Post tensioned timber was proposed to be used on constructing such multi-storey framed structures with additional seismic resisting system to reduce the damage on structure. Buckling Restrained Braces (BRB) as a well-designed, widely used seismic resisting system used on multi-storey steel structures has been modified into a timber steel BRB for artistically fitting into the proposed structure. This research project focuses on designing and testing a feasible Timber Steel BRB that can meet New Zealand design requirements. A detailed design procedure has been developed based on a case study in a 7 story office building located in Christchurch. Based on the case study, the design load and minimum displacement requirement for one full scale BRB is calculated as 668kN and 25mm. After preliminary Finite Element Modelling analysis and required strength calculations on performance of yielding core with different cross-section detail (cruciform, H-section, flat section and I-section). An I-section yielding core with a flange width to web height ratio of 0.42 is selected due to the lower requirement in restraining strength. With further design, the timber outer casing is separated into 4 pieces and glued together to encase the I-section shape. Due to the limitations in the testing machine, three 1:2.5 scale Timber-Steel BRBs are constructed and tested. The experimental tests show stable hysteresis loops which suggest good performance of the proposed Timber-Steel BRB and two test specimens with perpendicular to grain reinforcement are able to deform to the minimum required deformation which indicates this design is feasible to use in New Zealand. The results also indicate the timber reinforcement along the brace in both yielding core axes and the debonding agent for glue bound timber steel BRB are necessary.