This European Standard specifies, for plywood panels of any composition, symmetrical or not, a calculation method to derive some mechanical properties (strength and stiffness in bending, tension, compression, panel and planar shear) as well as density from the wood compounding the layers. NOTE Usually, the lay-up of the panels is symmetrical but, very often, the surface appearance of the face and the surface appearance of the back face differ, hence a difference between the mechanical properties of the respective veneers. Therefore, inThis case, the composition is not mechanically symmetrical and a symmetry independent calculation method is needed. Provided that structural characteristic values are taken for the layers, the resulting values for the panels can be used as characteristic values as required by EN 1995-1-1. Conversely, Annex A defines the procedures to derive the veneer properties, in bending, tension and compression, either from testing panels according to EN 789 and EN 1058 or from timber testing according to EN 408 or from imposed values defined in EN 338. Annex B provides practical spreadsheets, which are applications of the equations in the main part of this standard. Annex C provide an example for the calculation of bending strength, in accordance with Annex B.
EN 14272:2011 Referenced Document
EN 1058 Wood-based panels - Determination of characteristic 5-percentile values and characteristic mean values
EN 12369-2 Wood-based panels - Characteristic values for structural design - Part 2: Plywood
EN 14358 Timber structures - Calculation and verification of characteristic values
EN 325 Wood-based panels - Determination of dimensions of test pieces