Experimental and numerical study on optimization design of stretcher positions

In this study, the withdrawal strength of T-shaped joint was investigated through using Finite Element Method (FEM) and Analytic Method (AM). Firstly, the mechanical properties of wood were measured by conducting the experiment. In addition, the influence of friction coefficient between wood interfaces was studied with various size of contact area, direction of grain and pressure. Then, a mathematical model of oval mortise and tenon joint withdrawal strength was established based on linear elastic mechanics. Subsequently, the withdrawal strength of T-shaped joint was analyzed on the basis of numerical method with Finite Element Method (FEM) software. Finally, with the application of the experimental method, comparison and analysis were made between numerical method and analytic method. The results demonstrated that the consistency level between the numerical method and experiment was 83 %, which is more accurate than that between analytic method and experiment 80 %. As a results, the mathematical model was applicable to calculate the withdrawal strength of mortise and tenon joint which can also meet the engineering requirements of wood construction and wooden products structure design. In addition, the FEM applied in the study was more precise than analytic method while the latter was comparatively simple and convenient. These two methods were capable of evaluating the withdrawal strength of mortise and tenon joint, which can also be applied to structure design and optimization of wood construction and wooden products in order to make the design more scientific and reasonable.

Numerical study on effects of tenon sizes on withdrawal load capacity of mortise and tenon joint

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.