Effect of loading type (compression and tension) on mechanical properties, including elastic constants, yield strength and ultimate strength of beech (Fagus orientalis) wood were studied based on experimental and numerical methods. The mechanical behaviors of beech wood in compressive and tensile states were simulated by finite element method (FEM) using mechanical parameters measured in an experiment. The results showed that the effect of loading types on mechanical properties of beech was statistically significant. The elastic moduli measured in tension were all bigger than those in compression, but the Poisson’s ratios determined in compression were bigger than those in tension. In compressive state, the yield and ultimate strengths of beech in longitudinal grain orientation were all smaller than those measured in tensile state, while the yield and ultimate strengths of beech in radial and tangential directions were higher than those of longitudinal direction. The results of the FEM in compression and tension were all well consistent with those measured by experiments respectively, and the average errors were all within 13.69%. As a result, the finite element models proposed in this study can predict the mechanical behaviors of wood in tensile and compressive states.
The effect of tenon length and tenon width on withdrawal load capacity of mortise and tenon (M-T) joint was studied based on the finite element method (FEM), and the relationship of withdrawal load capacity relating to tenon length and tenon width was regressed using response surface method. The results showed that the tenon length and tenon width had remarkable effects on withdrawal load capacity of M-T joint T-shaped sample. The effect of tenon length on withdrawal load capacity was greater than tenon width. The regression equation used to predict the withdrawal load capacity was capable of optimizing the tenon sizes of M-T joint with R-square of 0.926. Using FEM can get more knowledge of M-T joint visually, and reduce the costs of materials and time of experiments.