Effect of size on tensile strength parallel to grain of high-performance wood scrimber

Abstract

With its high strength and excellent dimensional stability, high-performance wood scrimber (HPWS) holds significant promise for applications in load-bearing structures within buildings. However, understanding its behavior concerning size effects, particularly in terms of strength variation with stressed volume dimensions, is essential for establishing design parameters. Despite this importance, research on this aspect remains scarce. To address this gap, this study conducted tension tests on 304 specimens divided into 10 groups, covering a wide range of sizes, with the largest specimen’s volume 162 times that of the smallest. Utilizing the weakest link theory, the study investigated the size effect on tensile strength parallel to grain. Size effect factors were estimated using the shape parameter and slope methods, with discussions on differences related to volume, length, and cross-sectional area factors. It was found that the size effect related to the length and cross-sectional area were 0.0804 and 0.0671, respectively. This difference was due to the load-sharing ability within the cross-section, as the HPWS in tension resembles a net-like structure more than a chain-like structure. The specimens with the smallest cross-section didn’t exhibit the greatest strength. This was because the effects of sawing are particularly severe for very small specimens. This issue requires careful consideration when developing calculation methods. Finally, a calculation method for the tensile strength reduction coefficient, considering size effects, was proposed and demonstrated to align well with experimental findings. This comprehensive analysis serves to advance the structural utilization of HPWS as an innovative building material.