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001876

Dipl.-Ing. (FH) Bastian Kuhn, M.Sc.

2024-03-13

Design of Timber Panel Wall with Beam Panel Thickness Type

In this article, the calculation of a timber panel wall with the beam panel thickness type is compared to a manual calculation.

System

Beam material = C24
ϱ_m,s (C24) = 420 kg/m³
Beam cross-section = 6/16 cm
Sheathing material = OSB 3
ϱ_k,p (OSB) = 550 kg/m³
t = 15 mm with one-side sheathing
Staples d=1.5 mm, t=50 mm
Staple spacing a_v = 75 mm (single row)
Grid = 62.5 cm
Wall length = 2.56 m
Wall height = 2.75 m
Load 8 kN horizontal
Load 5 kN/m vertical
Service Class 1

Slip Modulus k_ser

In the beam panel generator, the slip modulus is calculated according to Table 7.1 when performing a calculation according to Eurocode 5. This is explained for fasteners in this article.

k_{ser} = ρ_{m}^{1.5} \cdot \frac{d^{0.8}}{80}

Slip Modulus Fasteners

According to EN 1995‑1‑1, the square root of the mean value of the density of the sheathing and the columns is used to calculate the slip. If the mean value of the raw density is not available, the characteristic value of the material library is multiplied by the value 1.15 according to ÖNORM EN 1995‑1‑1 (NA.7.1‑E1). This value can be user-defined in the material parameters.

Modification Factor for Characteristic Density

\sqrt{420 kg / m ³ \cdot (1.15 \cdot 550 kg / m ³)} = 515 kg / m ³

Mean Value

Since the fastener has two nails, the slip modulus is calculated as follows.

k_{ser} = 2 \cdot {515 kg / m ³}^{1, 5} \cdot \frac{1, 5 {mm}^{0, 8}}{80} = 404, 6 N / mm

Slip Modulus

In the attached file, this value is also calculated for the beam panel.

The sheathing of the timber panel wall is connected linearly elastic to the timber posts.

Divided into one meter of length, this results in:

1,000 mm / 75 mm = 13.33 connectors

→ 13 connectors x 404.6 N/mm = 5,260 kN/m²

Actually, the unit is kN/m, but the stiffness is defined on a line, and therefore refers to one meter.

--> kN/m x m =kN/m²

Timber Panel Wall Stiffnesses

Timber Panel Wall

The tie rod is not taken into account!

Loading

LC1 self-weight 5 kN/m (vertical)
LC2 Wind 8 kN (horizontal)
CO = 1.35 LC1 + 1.5 LC2
Calculation according to the linear static analysis

Timber Panel Wall

Horizontal deformation behavior of the timber panel wall pure horizontal load (8 kN):

Fastener in cladding u_k,inst

u_{k, inst} = \sum_{} \frac{S_{v, 0} \cdot S_{v, 0}}{k_{ser}} = (2 \cdot l + 2 \cdot h) \frac{a_{v}}{k_{ser} \cdot l ²} \cdot F

Sheathing, Fastener

u_{k, inst} = (2 \cdot 2560 mm + 2 \cdot 2750 mm) \frac{75 mm}{404, 6 N / mm \cdot 2560 mm ²} \cdot 8000 N = 2, 40 mm

u_k,inst 8kN

Shear panel cladding u_G,inst

u_{G, inst} = \frac{F}{G \cdot t} \cdot \frac{h}{l}

Sheathing Shear

u_{G, inst} = \frac{8000 N}{1080 N / mm ² \cdot 15 mm} \cdot \frac{2750 mm}{2560 mm} = 0, 53 mm

u_G,inst 8kN

Ribs (axial force members) u_E,inst

u_{E, inst} = \frac{2}{3} \cdot \frac{F}{E_{0} \cdot A} (l + \frac{h^{3}}{l^{2}})

Ribs Members

u_{E, inst} = \frac{2}{3} \cdot \frac{8000 N}{11000 N / mm ² \cdot 9600 mm ²} (2560 mm + \frac{2750 {mm}^{3}}{2560 {mm}^{2}}) = 0, 29 m m

u_E,inst 8kN

The sum of the deformations for the horizontal deflection of 8 kN is 3.2 mm. This corresponds to the calculation in RFEM.

When calculating the load combination (1.35 LC1 + 1.5 LC2), the deflection of 4.8 mm for the force of 12 kN in the manual calculation corresponds well to the calculation in the program of 4.8 mm.

In further design checks, the internal forces and the design should be compared.

Author

Mr. Kuhn is responsible for developing products for timber structures, and provides technical support for our customers.

References

Blass, H. J., Ehlbeck, J., Kreuzinger, H., & Steck, G. (2005). Erläuterungen zu DIN 1052: Entwurf, Berechnung und Bemessung von Holzbauwerken, (2nd ed.). Karlsruhe: Bruderverlag.
CEN. (2010). Eurocode 5: Design of Timber Structures – Part 1-1: General – Common Rules and Rules for Buildings; DIN EN 1995-1-1:2010-12. Berlin: Beuth Verlag GmbH.

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Design of Timber Panel Wall with Beam Panel Thickness Type

System

Slip Modulus kser

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Slip Modulus k_ser