Numerical analysis of stress and strain in a wooden chair/Numericka analiza naprezanja i deformacija u drvenoj stolici

This paper presents numerical analysis of stress and strain conditions of a three-dimensional furniture skeleton construction and its joints. The finite volume method is used in the calculation. Orthotropy of the wood material is accounted for by approximating it with an isotropic material whose elastic modulus and Poisson's ratio are calculated by employing the least-square method. The displacement of the edge point for the loaded joint was also determined experimentally. The agreement of results of the calculation and experimental data can be considered satisfactory. The numerical results presented in this paper also provided an opportunity for identification of the region with the largest load and strain in the complex chair skeleton construction, which is one of the most complex pieces of furniture. Key words: corner joint, chair, displacement, stress, wood, numerical analysis U radu je prikazana numericka analiza naprezanja i deformacija prostorne okvirne konstrukcije namjeetaja i spojeva koji se u njoj pojavljuju. Za proracun je koristena metoda konacnih volumena. Zanemarena je ortotropija, a modul elasticnosti i Poissonov omjer za simulirani izotropni materijal aproksimirani su metodom najmanjih kvadrata. Za opterec eni kutnik pomak rubne tocke i eksperimentalno je odreden. Rezultati proracuna zadovoljavajuce se slazu s eksperimentalnim podacima, pa se predlozeni numericki algoritam mode primijeniti za analizu krutosti i cvrstoce spojeva. Numericki rezultati dani u ovom radu omogucili su identificiranje mjesta najveceg opterecenja i deformacije u slozenoj okvirnoj konstrukciji stolice kao jednome od najslozenijih komada namjeetaja. Kljucne rijeci: kutni spoj, stolica, pomak, naprezanje, drvo, numericka analiza