Vol.:(0123456789) 1 3 Eur. J. Wood Prod. DOI 10.1007/s00107-017-1160-4 ORIGINAL Finite element simulations of the loading and deformation of plywood seat shells Srečko Vratuša 1  · Mirko Kariž 2  · Nadir Ayrilmis 3  · Manja Kitek Kuzman 2   Received: 7 October 2015 © Springer-Verlag Berlin Heidelberg 2017 1 Introduction The design of furniture has evolved through a process of trial and error (Eckelman and Sudarth 1969; Gustafsson 1996a, b; Tankut and Tankut 2011). Furniture design is almost always based on what is learned from the traditions in handicraft manufacturing (Gustafsson 1997). Today, the engineering design of furniture can be accomplished by uti- lizing solid modeling and structural analysis software. All the parts of a wooden product can be modeled parametri- cally and the required changes can be readily optimized, making use of the advantages provided by solid modeling. Likewise, strength calculations for the designed prod- uct can be made by means of computer-aided structural analysis software (Kasal 2006; Colakoglu and Apay 2012; Smardzewski et al. 2014). With the use of modern comput- ers and sophisticated mathematical models it is possible to fnd new ways to design chairs in order to utilize the mate- rial much more efciently than before (Gustafsson 1996b). Standard patterns of furniture can be handed down from generation to generation, and as long as the new designs do not difer too much from the old ones, their performance can be judged from past experience (Eckelman 1966). In furniture design and construction, it is not only the esthetic and functional preferences that are taken into consideration, but also the rigidity and strength requirements (Smardze- wski 1998). Considering all these requirements during the development phase is a challenging job that can be facili- tated by modern modelling software with the analysis of the structure. The fnite element method (FEM) is a numerical tech- nique used in the analysis of the behavior of materials or systems (Gustafsson 1995, 1996b). Although the methods have already been developed for the analytical processing Abstract Modern 3D modelling software reduces the need for a large number of prototypes, means fewer prod- uct-development cycles and lower costs (time/cost), as well as improving the quality of furniture designs. However, the mechanical testing of fnal products is still required in order to confrm the simulation results. In this study the theoreti- cal behaviors of diferent 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 signifcant for the diferent shells and increased with loading above the elastic deformation limit of the material. It was concluded that the SolidWorks ® simulation software could be efectively used in the calculation of the component displacements, strains, and stresses of seat designs subject to internal and external loads. * Manja Kitek Kuzman manja.kuzman@bf.uni-lj.si Srečko Vratuša srecko.vratusa@fa.uni-lj.si Mirko Kariž mirko.kariz@bf.uni-lj.si Nadir Ayrilmis nadiray@istanbul.edu.tr 1 Faculty of Architecture, University of Ljubljana, Zoisova 12, SI-1000, Ljubljana, Slovenia 2 Department of Wood Science and Technology, Biotechnical Faculty, University of Ljubljana, Rožna dolina, Cesta VIII/34, SI-1000, Ljubljana, Slovenia 3 Department of Wood Mechanics and Technology, Forestry Faculty, Istanbul University, Bahçeköy, Sariyer, 34473 Istanbul, Turkey