Finite Element Analysis And Optimal Design Of Vitex Negundo Reconstituted Timber Furniture

With economic development and improvement in the living standards, people’s demand for wood furniture has been getting larger and larger in recent years. But the increasing scarcity of natural forest resources, is far from enough to meet the huge demand gradually. Thus, it become an urgent and effective way to develop and utilize small dimension wood from plantation forest. Based on the social needs and ecological problems, the new material, Vitex negundo scrimber, as furniture wood, was studied. The results showed that good strength properties of Vitex negundo reconstituted timber make it easy to apply to furniture production.The basic physical and mechanical performances of Vitex negundo scrimber were tested by experiment in this paper. The test results of dynamic elastic modulus obtained by three kinds of FFT nondestructive testing methods were compared with static modulus of elasticity acquired by bend destructive tests, and the relationship between the different modulus of elasticity and static bending strength was analyzed by using linear regression analysis, the prediction model of static bending strength of Vitex negundo reconstituted timber was proposed as well. The Vitex negundo scrimber was used for furniture design, and the structural strength of which under static loading was calculated and analyzed by using ABAQUS finite element method, which showed that it is reasonable for the structure design of wood furniture made of Vitex negundo reconstituted timber, and the structural strength of which is high enough to be safely used. Specific test and analysis results are as follows:(1) Three different nondestructive testing methods were used to test dynamic elastic modulus of Vitex negundo scrimber, which were longitudinal resonance, bending vibration and longitudinal wave propagation respectively. The results showed that the dynamic elastic modulus tested by the former one is slightly higher than the later two measured, which is nearly equal to each other in numerical value.(2) The static modulus of elasticity and the static bending strength of Vitex negundo reconstituted timber were tested by using bend destructive tests, which showed that the test results of dynamic elastic modulus obtained by three kinds of FFT nondestructive testing methods are all bigger than static modulus of elasticity acquired by bend destructive tests, and variation coefficient of dynamic elastic modulus is larger than that of static modulus of elasticity.(3) It was showed that there is significant linear correlation between different elastic modulus and static bending strength based on the regression analysis. According to the correlation between the two, the prediction model of static bending strength was built based on the different elastic modulus, and it was found that the predicted values are slightly higher than the measured values by comparison of the both two, which is, the carrying capacity of Vitex negundo scrimber would be slightly overrated.(4)The stress-strain-situation of furniture structure made of Vitex negundo reconstituted timber under static loading was analyzed by using ANSYS finite element method. The results showed that the structural deformation of which is small, and the maximum stress appeared in the structure is also within the bearable limit. Therefore, it is reasonable for the structure design of wood furniture made of Vitex negundo reconstituted timber, and the structural strength of which is high enough to be safely used.(5)Based on force analysis of Vitex negundo reconstituted timber furniture structure through finite element method, optimal design was carried out for furniture structure,which reduced the loss of materials and the cost of design,and made the structure design more reasonable under the premise of ensuring the strength requirement.