Flexural bearing capacity and stiffness of stiffened hollow glulam beams: Experiments, finite element analysis and calculation theory

Abstract

• Twenty-seven specimens were designed and four-point bending experiments were carried out. • The failure modes, elastic stiffness, bearing capacity, and ductility coefficients of the solid beam, hollow beam, stiffened hollow beam were compared and analyzed. • Numerical models were developed to analyze the mechanical performance of stiffened hollow beams and were validated by the experimental results. • The calculation equations for ultimate bearing capacity and bending stiffness of glulam beam with three different section forms were established. Inspired by the section structure of natural bamboo, a rectangular hollow glulam beam with stiffeners is proposed. In this paper, experimental study and finite element simulation were carried out for such glulam beams. The results showed that compared with hollow beam, the initial bending stiffness, ultimate bearing capacity and ductility of the stiffened hollow glulam beams improved significantly, indicating that stiffeners enhanced the local stability behavior of the webs and the bottom plates. Meanwhile, the calculation equations for ultimate bearing capacity and bending stiffness of glulam beam with three different section forms were established based on the material mechanics and constitutive model. The accuracy was verified by experiments and finite element analysis. This paper shows that the proposed stiffened hollow glulam beam can be used as a replacement for solid timber beam, which can save material while maintain a desirable mechanical performance.