# Consideration of Holes in Tension Design

### Tips & Tricks

001523 13 June 2018
For the tension design according to Clause 6.2.3 EN 1993-1-1, the following formulas are given to determine the tension resistance.

$\begin{array}{l}\mathrm{Equation}\;6.6:\;{\mathrm N}_{\mathrm{pl},\mathrm{Rd}}\;=\;\frac{\mathrm A\;\cdot\;{\mathrm f}_\mathrm y}{{\mathrm\gamma}_{\mathrm M0}}\\\mathrm{Equation}\;6.7:\;{\mathrm N}_{\mathrm u,\mathrm{Rd}}\;=\;\frac{0.9\;\cdot\;{\mathrm A}_\mathrm{net}\;\cdot\;{\mathrm f}_\mathrm u}{{\mathrm\gamma}_{\mathrm M2}}\end{array}$

Whereas in RF-/STEEL EC 3 the gross cross-section area A is given by the selection of the cross-section, the net cross-section area Anet has to be defined. It can be performed in Table "1.12 Parameters - Members". It is possible to define a net cross-section area for member start and member end. As soon as this reduced cross-section area is defined, RF-/STEEL EC3 analyzes both formulas on the minimum tension resistance. The results can be checked after the calculation in a clearly manner in the result table or graphically in the RFEM/RSTAB window.

#### Design Example

A frame is given which is braced by two tension members L70x7. A tensile force of 176.78 kN is determined in the effective diagonal. The angle should be connected with a bolt M20.

In input window 1.12, a net surface of 9.4 cm² - (2.1 cm ∙ 0.7 cm) = 7.93 cm² will be defined.

The design is possible by using the tension resistance according to Equation 6.7.