Finite element simulations of the loading and deformation of plywood seat shells
Modern 3D modelling software reduces the need for a large number of prototypes, means fewer product-development cycles and lower costs (time/cost), as well as improving the quality of furniture designs. However, the mechanical testing of final products is still required in order to confirm the simulation results. In this study the theoretical behaviors of different plywood seating shells (using the SolidWorks® FEM simulation software) were compared with the real results obtained using tests to measure the deformation of the backrest. The deviations of the actual deformation from the simulation were significant for the different shells and increased with loading above the elastic deformation limit of the material. It was concluded that the SolidWorks® simulation software could be effectively used in the calculation of the component displacements, strains, and stresses of seat designs subject to internal and external loads.
Finite element analysis of wooden chair strength in free drop
Wooden furniture is being widely used in all countries due to its convenience and being produced from the natural raw material. In furniture design esthetic, ergonomics and safety are the main criteria. Safety means the strength of furniture. Unfortunately, most of the time the strength of furniture is not taken into account in design as much as esthetic and ergonomics. This leads to the use of excess material meaning high cost or usage of less material causing some dangers in use. In literature, the first study of finite element method (FEM) in furniture design was in 1966. The technological developments in software and hardware promoted those studies. In those researches, the strength analysis had been done for different kinds of wood. In one of the latest studies, irregular types of sitting on the chair had been analyzed by FEM. In our study, the chair produced from southern red oak (Quercus falcata), pine red (Pinus resinosa) and Spruce Engelmann (Picea engelmannii) wood are simulated by free drop from two different heights defined in packaging standards. The strength at different parts and corners of the chair is analyzed as free dropped on its front legs by ANSYS TM . In this study, some suggestions are developed for furniture designers and manufacturers.
Chair load analysis during daily sitting activities
One of the greatest difficulties in chair design stems from the fact that the act of sitting is usually studied as a static activity rather than a dynamic one. With this in mind, this research has been developed to set and define the loads that occur in a Eucalyptus wood chair during different postures and using ergonomic concepts. In vivo measurements were performed in order to obtain a realistic body/chair interaction and loads were measured using an instrumented chair. This study was planned as a pilot study to provide initial information about loads during daily sitting activities believing that this will result in more well designed furniture.