Analisis Pengaruh Tekuk Torsi Lateral Penampang Balok Prismatis dan Non-Prismatis pada Gable Frame

Abstract

Prismatic and non-prismatic beams are two types of beams commonly used in construction, each with unique characteristics related to cross-sectional shape and material distribution. Prismatic beams have a uniform cross-section along their length, while non-prismatic beams have varying cross-sections, either continuously or discontinuously. This study aims to analyze the effect of lateral torsional buckling on prismatic and non-prismatic beams, focusing on the behavior of beams under load without considering joint effects. Through this approach, the study is expected to provide a deeper understanding of the structural behavior of prismatic and non-prismatic beams and contribute to the development of more effective design methods, particularly in enhancing lateral torsional buckling stability under bending loads. The study analyzes the influence of free span length (Lb) and beam type (prismatic and non-prismatic) on moment capacity (Mn). The results show that moment capacity increases with the reduction of free span length, with non-prismatic beams consistently showing higher moment capacity than prismatic beams for the same free span length. Notably, the non-prismatic beam with Lb = 1,5 m achieves the highest moment capacity of 1932,7 kN.m, highlighting the effectiveness of non-prismatic design for short spans. These findings indicate that non-prismatic design is more optimal for increasing moment capacity, especially in structures with shorter free spans. This study provides a basis for predictive models that consider free span length and cross-sectional shape in determining moment capacity. These findings are expected to aid in the design of efficient and moment-resistant structures and serve as a reference in selecting beam type and free span length for construction applications requiring high durability.