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.
Furniture design by use of the finite element method
The design of structural members of furniture is almost never the subject for mathematical considerations. Instead, the designer rests on empirical experience and constructs for example chairs with dimensions of structural members based on tradition and aesthetic reasons. By the much more common use of computers it is nowadays possible to use modern finite element programs in various stages of the design process. In this paper we show how already simple calculations lead to a totally different design of a chair. We also emphasise the need for more research on wood in “furniture size” and not only as part of building structures. There is no need for “triple-security” values when a chair is to be designed but instead it is possible to balance on the edge of the mechanical strength in the wooden members. Further, it is possible to use only wood details where no knots, or other errors are present. This will lead to substantially thinner members in the wooden chair.ZusammenfassungDas Design von Möbelelementen ist nur selten Gegenstand mathematischer Überlegungen. Stattdessen stützen sich die Designer auf Ehrfahrungswerte und die Konstruktion von Einzelstücken aufgrund traditioneller oder ästhetischer Betrachtungen. Mit Hilfe von Computern ist es jedoch leicht möglich moderne FEM-Programme für die verschiedenen Entwicklungsschritte eines Designs zu nutzen. Wird betonen hier auch die Notwendigkeit weiterer Grundlagenforschung für Abmessungen im Möbelbereich nicht nur bei Baukonstruktionen. Für die Stuhlkonstruktion ist auch keine Dreifach-Sicherheit nötig, sondern man kann die mechanische Festigkeit der Konstruktionselemente voll ausnutzen. Zudem ist es möglich, durch Vorsortieren typische Holzfehler ganz unberücksicht zu lassen. Das wiederum ermöglicht schlankere Einzelteile für das Stuhldesign.
Strength analysis of chair base from wood plastic composites by finite element method
Abstract The present paper is aimed at solid modelling of an office chair base made up of wood thermoplastic composites by using finite element method. This is an attempt to evaluate the feasibility of substituting conventional materials in furniture production by wood composite materials. As the structural performance of any furniture product is utmost important to the manufacturers, it is essential for the product designers to build a prototype and test it under different loading conditions. Owing to the complexities involved in the deformation process of wood composite products, a powerful analysis technique (finite element analysis) has been applied to validate the product prototype.