Description
The example covers the determination of cross-section properties for both the gross and effective cross-section of a cold-formed C-section with edge stiffeners according to DIN EN 1993-1-3:2010-12 [1].
The stress cases considered are pure compression and pure bending about the z-z axis.
The underlying cross-section corresponds to Example H from the design examples of ECCS-TC7 [2].
| Material | Modulus of elasticity | E | 210,000.00 | N/mm² |
| Poisson's ratio | ν | 0.30 | ||
| Shear modulus | G | 80,769.23 | N/mm² | |
| Basic yield strength S355 | fyb | 355.00 | N/mm² | |
| Partial safety factor for cross-section resistance | γM0 | 1.00 | ||
| Geometry | Height | h | 102.00 | mm |
| Width | b | 120.00 | mm | |
| Thickness | t | 2.00 | mm | |
| Inner radius | ri | 10.00 | mm | |
| Lip length | c | 26.00 | mm |
RSECTION Settings
Modeled in RSECTION 1.11.0011
Results
| Reference Value | ECCS | RSECTION 1 | Deviation |
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| Area A | 7.34 cm2 | 7.34 cm2 | 0.00 % |
| Centroidal distance from the web ey | 50.96 mm | 50.96 mm | 0.00 % |
| Centroidal distance from the lip yy | 67.04 mm | 67.04 mm | 0.00 % |
| Moment of inertia Iy | 139.10 cm4 | 139.13 cm4 | 0.02 % |
| Moment of inertia Iz | 140.45 cm4 | 140.49 cm4 | 0.03 % |
| Section modulus Wz | 20.64 cm3 | 20.65 cm3 | 0.05 % |
| Radius of gyration iy | 43.53 mm | 43.54 mm | 0.02 % |
| Radius of gyration iz | 43.74 mm | 43.75 mm | 0.02 % |
| Distance of the shear center from the centroid ySC | 115.31 mm | 115.33 mm | 0.02 % |
| Torsional constant It | 0.098 cm4 | 0.098 cm4 | 0.00 % |
| Warping constant Iω | 4310.67 cm6 | 4312.75 cm6 | 0.05 % |
| Asymmetry parameter rz | 16.84 mm | 16.85 mm | 0.06 % |
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| Area A | 4.67 cm2 | 4.71 cm2 | 0.86 % |
| Centroidal distance from the web ey | 42.72 mm | 45.83 mm | 7.28 % |
| Centroid displacement eN,y | 8.24 mm | 5.13 mm | 37.74 % |
| Moment of inertia Iy | 87.24 cm4 | 88.83 cm4 | 1.82 % |
| Moment of inertia Iz | 94.80 cm4 | 98.74 cm4 | 4.16 % |
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| Area A | 6.86 cm2 | 7.02 cm2 | 2.33 % |
| Centroidal distance from the web ey | 46.87 mm | 48.06 mm | 2.54 % |
| Moment of inertia Iy | 129.73 cm4 | 133.72 cm4 | 3.08 % |
| Moment of inertia Iz | 122.49 cm4 | 126.88 cm4 | 3.58 % |
| Section modulus of the lip Wz | 17.04 cm3 | 17.89 cm3 | 4.99 % |
| Section modulus of the web Wz | 25.59 cm3 | 25.86 cm3 | 1.06 % |
The deviations of the effective cross-section properties that are calculated from the literature example are a result of the different consideration of distortional buckling.
In the literature example, the critical load is determined analytically, and the effect of distortional buckling is only taken into account by reducing the cross-section thickness in the areas of the stiffening elements.
RSECTION, on the other hand, uses a numerical eigenvalue analysis to determine the critical load. Based on the mode shape, the thickness reduction is carried out by section over the entire cross-section, depending on the local degree of deformation.
