WOOD RESEARCH Volume 69, Number 3, 2024
RUNZHONG YU, YAN LIU, ARIF CAGLAR KONUKCU, and WENGANG HU

A METHOD OF SIMULATING SEAT LOAD FOR NUMERICAL ANALYSIS OF WOOD CHAIR STRUCTURE

This study aimed to investigate the characteristic values of the human-seat interface in a normal sitting posture, and to numerically mode the load on the chair seat for the structural design of chairs. The stress distributions and the characteristic values of seat were measured under normal sitting posture by using a human body pressure distribution measurement system considering the effects of gender and body mass index (BMI). The stress distribution on the seat was then numerically modeled using three modeling methods. The observed results and the numerical analysisresults were compared. The results showed that an inverted U-shaped pressure distribution was observed in normal sitting posture. The stress was concentrated on the ischial tuberosity with a maximum value of 0.066 MPa. The ratio of the load on the seat to the gravity of the human body weight was about 65.3%. The numerical model established using the body pressure mapping method was superior to those of the uniform load method and the standard loading pad method in terms of stress distribution, maximum stress, and contact area

WOOD RESEARCH Volume 69, Number 1, 2024
WENGANG HU, WENJIE FU, and YUAN ZHAO

OPTIMAL DESIGN OF THE TRADITIONAL CHINESE WOOD FURNITURE JOINT BASED ON EXPERIMENTAL AND NUMERICAL METHODS

In this study, computer aided technology was utilized to improve the traditional grid shoulder mortise-and-tenon joint (GSMTJ). Firstly, the traditional GSMTJ was redesigned through using separated loose tenon by the computer aided design (CAD) software called AutoCAD. And then the mechanical strengths of the traditional GSMTJs and the improved GSMTJs were compared and analyzed using the experimentally validated finite element method (FEM) based on the computer aided engineering (CAE) software called ABAQUS. Finally, the GSMTJs were further investigated from perspective of manufacturing efficiency using the computer aided manufacturing (CAM) software called JDSoft SurfMill. Based on the above simulation analysis, the improved GSMTJ was validated to be equivalent strength, high manufacturing efficiency increasing by 11.5%, low processing load ratio decreasing by 30%, as well as less wood material cost reducing by 3.6% compared with the traditional GSMTJ. The proposed improved GSMTJ was validated to be more suitable to modern wood processing machines. In addition, the methodology of combining the CAD, CAE, and CAM to wood products design was proofed efficient, economic, and feasible, and can be also used in design of other products

WOOD RESEARCH Volume 66, Number 1, 2021
WENGANG HU and Bingrui Chen

Experimental and numerical studies on mechanical behaviors of beech wood under compressive and tensile states

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.

WOOD RESEARCH Volume 66, Number 2, 2021
Tianxing Zhang and WENGANG HU

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.