ANALISIS PERILAKU SIKLIK DAN KAPASITAS DISIPASI ENERGI BAMBOO BUCKLING-RESTRAINED BRACES (B-BRB)

Abstract

Bali Province is characterized by a high level of seismic hazard, while the dominant building typology consists of low-rise structures with a maximum height of four stories, consistent with regional spatial planning regulations and local architectural practices. Although seismic forces acting on low-rise buildings are generally smaller than those experienced by high-rise structures, the risk of structural damage remains significant due to the limited availability of economical and easily implementable seismic energy dissipation systems in the domestic construction market. This condition contributes to the low adoption of seismic damping technologies and continued reliance on imported devices. This study aims to develop a conceptual model of a Bamboo Buckling-Restrained Brace (B-BRB) as a low-cost and sustainable seismic energy dissipation system suitable for low-rise buildings in Bali. Bamboo is selected as the primary material due to its abundant availability, rapid growth, and favorable strength-to-weight ratio, making it a promising candidate for locally sourced seismic damping devices. The research methodology includes the formulation of a conceptual and mechanistic model of the B-BRB and the derivation of fundamental equations for determining its design dimensions. Numerical modeling using Finite Element Analysis (FEA) was conducted to evaluate the structural response of the device under displacement-controlled lateral cyclic loading conditions up to a story drift of ±2.5%. The simulation results demonstrate that the B-BRB with a target axial capacity of 75 kN exhibits a highly stable and symmetric hysteretic response without experiencing premature global buckling or severe pinching behavior. The device achieves a cumulative energy dissipation capacity of 4,500 kN·mm at the peak cycle, with a gradual lateral stiffness degradation from 3.5 kN/mm to 2.9 kN/mm, and an average equivalent viscous damping ratio of 3.0%. Based on these findings, it can be concluded that the conceptual model of the B-BRB represents an analytically and numerically viable, eco-friendly, and cost-effective seismic damping solution to enhance the seismic resilience of low-rise structures (≤ 4 stories) in earthquake-prone regions.