Fatigue strength of laminated bamboo lumber

Abstract

Today, the global demand for renewable and sustainable materials is higher than ever. A promising material in this regard is the fast-growing natural resource bamboo. Research activities in the field of bamboo have increased in recent years due to its availability in many regions of the world and its positive influence on the ecosystem (e.g., high potential for carbon restoration). The mechanical properties of bamboo are comparable or even superior to those of commonly used wood species. Processing the raw bamboo culms into engineered bamboo products can enhance these properties, as it eliminates many naturally grown flaws and misalignments of the culm. In this study, the properties of laminated bamboo lumber (LBL) made from Phyllostachys pubescens (“Moso” bamboo) under fatigue loading in tensile direction were explored. Understanding the fatigue behavior of materials used in various technical fields is essential because all components are exposed to cyclic loads. Additionally, the load levels leading to material failure are significantly lower than the characteristic values measured under (quasi)-static loading. The initial cyclic tests of the LBL specimens yielded very promising results for potential applications in technical fields, such as civil engineering. The digital image correlation (DIC) systems were used to gain an initial understanding of the damage mechanisms that led to the failure of the specimens. It could be proven, that the nodal areas of the bamboo tend to be high-loaded and are preferred initiation points of fracture.