Introducing a New Method of Using Roller Bearings Around the Core Plate of All-Steel Buckling Restrained Braces

Various bracing systems can be used to withstand lateral displacements caused by earthquakes and wind. One of these systems is Buckling Restrained Braces (BRBs), which consist of a steel core known as a "core plate" and a buckling restraining mechanism (BRM) made of full steel, concrete-steel, or other materials. This study presents a novel method to enhance the performance of all-steel BRBs. In this new method, a lubricated perforated steel plate with roller bearings (small solid steel cylinders) is attached to both sides of the core plate within the BRM. During plastic elongation and contraction of the core plate due to tension or compression loads, these movements occur on the roller bearings, which are housed in a grease-filled space. As a result, the friction between the core plate and the BRM is reduced, preventing the transmission of axial forces to the BRM. Additionally, the reciprocating movement of the core plate inside the BRM is smoothed, eliminating the risk of premature core plate failure. Finite element analysis has been conducted to analyze various types of all-steel BRBs with and without the new method, demonstrating the advantages of the proposed approach. The inclusion of roller bearings in the samples reduces frictional forces on the sheath by at least 45% and up to 63% compared to similar samples without roller bearings.