Broch

M1 BSP crossplan
Design according to
ETA-09 / 0036
General
The following applies for
a 5-layer symmetrical
lay-up:
Flexibility factors γ
12 Mayr-Melnhof Kaufmann
STRUCTURAL DESIGN
Design of the cross-laminated timber may be carried out according to EN 1995-1-1 and EN
1995-1-2 allowing for Appendices 2 to 4 of the European technical approval. Only lamellas
which are arranged in the direction of the mechanical stress may be taken into consideration
for calculation of the characteristic cross-sectional values. Reference must be made to the
characteristic strength and stiff ness of the solid timber according to to Appendix 3 (of European
Technical Approval 09-0036) for designing the components made of cross-laminated timber
in accordance with E 1995-1-1. Diff erent stiff nesses must be taken into consideration in both
main directions for cross-laminated timber with multi-axial spaning in both main directions.
Panel stress of the cross-laminated timber
The eff ective bending stiff ness depends on the eff ective moment of inertia Ieff . Calculation of
the eff ective moment of inertia and therefore of the eff ective bending stiff ness time is carried
out acc. to E 1995-1-1 (Section 9.1.3 and Appendix B):
� Distances between centres of gravity:
with
and
for symmetrical lay-up
The fl exibility factors γ allow for the shear deformation (rolling shear) of the cross-wise layers,
the expression of EN 1995-1-1 should be replaced by
� The fl exibilities thus arise from:
� where:
E 1,3 = 11600 N / mm² modulus of elasticity for C24
G 9090 = 50 N / mm² modulus of shear for C24
l = decisive width between supports
where
where
t tot
individual moment of inertia of longitudinal layers i = 1 to 3
areas of the longitudinal layers
t 1
t 2
t 3
b
t 1
t 2
Version 1 / 2011