Stresses in Cross Sections of Elements of Chair and Stool Frames

6.2.2.1 Stresses in Rectilinear and Slightly Curved Elements

After specifying the internal forces, the maximum stresses are calculated by using known equation of the strength of materials:

Sib

-H

(6.32)

= kA ’

(6.33)

rmax

smax

where

N force normal to the cross section, N force tangent to the cross section, M bending moment,

A area of the cross section,

W indicator of the strength of the cross section, k coefficient determining the shape of the cross section.

During the designing of tables or chairs, the characteristics of rectangular and round cross sections are most commonly used. Characteristics of these cross sec­tions are provided in Table 6.3.