Stress and Strain Analysis of Plywood Seat Shell

Seid Hajdarević,Elmedin Mešić,Sandra Martinović,Murčo Obućina

doi:10.5552/drvind.2019.1825

Abstract

In this paper, the stress and strain analysis of common laminated wood seat shell is performed. Experimental stiffness evaluation is conducted by measuring displacement of the point on the backrest, and experimental stress analysis is carried out by tensometric measuring at the critical transition area from the seat to the backrest. Finite element analysis is carried out layer by layer with a “2D linear elastic model” for orthotropic materials. Good matching is found between numerical and experimental results of displacement. It is also shown that the results of the principal stress in the measurement points of the seat shell compare favourably with experimental data. The applied in-plane stress analysis of each individual veneer is not applicable for interlaminar stress calculations that are a significant factor in curved forms of laminated wood. Curved forms of laminated wood products require more complex numerical analysis, but the method can be used to achieve approximate data in early phase of product design.

Highlights

Experimental stiffness evaluation is conducted by measuring displacement of the point on the backrest, and experimental stress analysis is carried out by tensometric measuring at the critical transition area from the seat to the backrest
The numerical analysis of the effect of veneer composition on the mechanical properties of rectangular and curved form of laminated wood has been tested and the results show that curved forms require more complex analysis (Hajdarevic et al, 2017)
Similarity between numerical and experimental results of stress and strain analysis of the plywood seat shell allows the conclusion that the research models were designed correctly

Summary

Introduction

Laminated wood composites, such as plywood and curved veneer products, have a wide range of application in furniture industry. Plywood shells are common and basic elements of a certain type of chair constructions. There is a considerable interest in developing new complex forms of the seat shells due to rapid trend changes. A better understanding of specific mechanical and physical properties of laminated structure can lead to quality improvement of curved veneer products. Laminated wood products have a balanced construction made of veneer sheets and their properties depend on properties of individual veneers, veneers layout and parameters of production process.

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Conclusion