Perilaku struktur gable dengan rafter profil kastela akibat variasi posisi lubang terhadap tumpuan

Castellated steel sections are suitable for long-span structures and are commonly used as rafters in gable systems. A key issue in the design of castellated gable rafters is the determination of hole closure locations, which are typically applied only at connection regions, while holes outside these zones remain open, despite potential buckling risks. This study investigates the behavior of castellated gable rafters with variations in hole closure. The evaluated parameters include maximum lateral force, displacement, strain, and failure modes. Structural modeling was conducted using IDEA StatiCa, with S235 steel and grade 8.8 bolts. The structure consists of a 6000 mm column height, a 20 m span, and a 7° rafter inclination. The rafter uses a honeycomb section of 525×175×7×11, while the column uses a 600×200×11×17 section, with square holes measuring 354 mm. Closing the first two holes beyond the connection region increased lateral capacity by 17.19% and displacement capacity by 53.4%. The results indicate that hole closure significantly affects failure modes and should not be applied arbitrarily.