StruCla against Technosoft Raamwerken: timber beam
Beam 1 from a Technosoft Raamwerken calculation (release 6.85): a 50×100 mm C24 timber beam on two supports, span 1.5 m, G = 0.54 kN/m and Q = 0.82 kN/m, consequence class 1, service class 1, k_def = 0.6, ψ0 = 0.4, ψ2 = 0.3. The same beam was rebuilt in StruCla. All Technosoft values below are taken from its printed output; every StruCla value is taken from StruCla's own report of that beam, without hand calculations or extra combinations.
57 of 57values taken directly from StruCla's standard combinations and checks, equal within the rounding of the Technosoft output
0 hand calculationsno derived values, no extra combinations added by hand
0.36 / 0.36unity check, stresses (Technosoft / StruCla)
2.7 / 2.68 mmfinal deflection with creep, limit 6.0 mm
1.28 / 1.285 kNgoverning support reaction (ULS 6.10b)
Technosoft prints 2 decimals (sometimes 1). A difference smaller than half a unit of its last printed digit counts as equal. The percentage is the difference between StruCla and Technosoft relative to Technosoft; the largest value (1.5 %) comes from that rounding.
1. Forces and reactions (ULS) per combination: reaction R, bending moment M, shear force V
| Quantity | Technosoft | StruCla | Difference | Note |
|---|---|---|---|---|
| BC1 1.22·G: reaction R | 0.51 kN | 0.513 kN | +0.65 % | |
| BC1 1.22·G: moment M | 0.19 kNm | 0.192 kNm | +1.31 % | |
| BC1 1.22·G: shear force V | 0.51 kN | 0.513 kN | +0.65 % | |
| BC2 0.9·G (favourable): reaction R | 0.38 kN | 0.379 kN | -0.35 % | |
| BC2 0.9·G (favourable): moment M | 0.14 kNm | 0.142 kNm | +1.43 % | |
| BC2 0.9·G (favourable): shear force V | 0.38 kN | 0.379 kN | -0.35 % | |
| BC3 6.10a 1.22·G + 1.35·ψ0·Q: reaction R | 0.84 kN | 0.845 kN | +0.64 % | |
| BC3 6.10a 1.22·G + 1.35·ψ0·Q: moment M | 0.32 kNm | 0.317 kNm | -0.93 % | |
| BC3 6.10a 1.22·G + 1.35·ψ0·Q: shear force V | 0.84 kN | 0.845 kN | +0.64 % | |
| BC4 6.10b 1.08·G + 1.35·Q (governing): reaction R | 1.28 kN | 1.285 kN | +0.36 % | |
| BC4 6.10b 1.08·G + 1.35·Q (governing): moment M | 0.48 kNm | 0.482 kNm | +0.36 % | |
| BC4 6.10b 1.08·G + 1.35·Q (governing): shear force V | 1.3 kN | 1.28 kN | -1.18 % | |
| BC5 0.9·G + 1.35·Q: reaction R | 1.21 kN | 1.209 kN | -0.09 % | |
| BC5 0.9·G + 1.35·Q: moment M | 0.45 kNm | 0.453 kNm | +0.74 % | |
| BC5 0.9·G + 1.35·Q: shear force V | 1.2 kN | 1.21 kN | +0.74 % | |
| BC6 0.9·G + 1.35·ψ0·Q: reaction R | 0.71 kN | 0.711 kN | +0.11 % | |
| BC6 0.9·G + 1.35·ψ0·Q: moment M | 0.27 kNm | 0.267 kNm | -1.28 % | |
| BC6 0.9·G + 1.35·ψ0·Q: shear force V | 0.71 kN | 0.711 kN | +0.11 % |
2. Serviceability limit state: displacements and reactions
| Quantity | Technosoft | StruCla | Difference | Note |
|---|---|---|---|---|
| BC7 characteristic G + Q: displacement | 1.99 mm | 1.986 mm | -0.19 % | |
| BC7 characteristic: reaction | 1.04 kN | 1.036 kN | -0.41 % | |
| BC12 permanent G: displacement | 0.81 mm | 0.807 mm | -0.39 % | |
| BC12 permanent: reaction | 0.42 kN | 0.421 kN | +0.18 % | |
| BC9 quasi-permanent G + 0.3·Q: displacement | 1.16 mm | 1.161 mm | +0.05 % | |
| BC9 quasi-permanent: reaction | 0.61 kN | 0.605 kN | -0.78 % | |
| BC11 frequent G + 0.5·Q: displacement | 1.40 mm | 1.397 mm | -0.25 % | |
| BC11 frequent: reaction | 0.73 kN | 0.728 kN | -0.24 % | |
| BC8 permanent with creep (E0mean,fin): final deflection | 1.29 mm | 1.291 mm | +0.07 % | E0mean,fin: all × (1 + k_def) |
| BC9 quasi-permanent with creep (E0mean,fin) | 1.86 mm | 1.857 mm | -0.16 % |
3. Deflection checks (characteristic combination, relative to the chord)
| Quantity | Technosoft | StruCla | Difference | Note |
|---|---|---|---|---|
| w1 (permanent load, instantaneous) | 0.8 mm | 0.81 mm | +0.85 % | |
| w2 (creep) | 0.7 mm | 0.70 mm | -0.52 % | final deflection minus instantaneous deflection |
| w_inst (instantaneous, G + Q) | 2.0 mm | 1.99 mm | -0.69 % | Technosoft rounds to 0.1 mm |
| w_bij (creep + variable load) | 1.9 mm | 1.88 mm | -1.28 % | |
| w_net,fin (final, net) | 2.7 mm | 2.68 mm | -0.65 % | |
| Allowable w_inst and w_net,fin (L/250) | 6.0 mm | 6.00 mm | 0.0 % | |
| Allowable w_bij (L/333) | 4.5 mm | 4.50 mm | +0.10 % |
4. Timber strength check (EN 1995-1-1), governing combination BC4 / 6.10b
| Quantity | Technosoft | StruCla | Difference | Note |
|---|---|---|---|---|
| k_mod (service class 1, medium-term) | 0.80 - | 0.800 - | 0.0 % | |
| k_h (bending, h = 100 mm) | 1.08 - | 1.084 - | +0.41 % | |
| f_m,y,d | 16.02 N/mm² | 16.017 N/mm² | -0.02 % | |
| f_v,d | 2.46 N/mm² | 2.462 N/mm² | +0.06 % | |
| f_t,0,d | 9.68 N/mm² | 9.677 N/mm² | -0.03 % | |
| f_c,0,d | 12.92 N/mm² | 12.923 N/mm² | +0.02 % | |
| f_c,90,d | 1.54 N/mm² | 1.538 N/mm² | -0.10 % | |
| f_t,90,d | 0.25 N/mm² | 0.246 N/mm² | -1.54 % | |
| σ_m,y,d (M = 0.48 kNm) | 5.78 N/mm² | 5.781 N/mm² | +0.02 % | |
| l_ef (assumed: lateral restraint at 1.0 m, load on top) | 1100 mm | 1100.0 mm | 0.0 % | 0.9·1000 + 2·100. Without a restraint: 1550 mm |
| σ_m,crit | 131.18 N/mm² | 131.182 N/mm² | 0.0 % | Without a restraint: 93.1 |
| λ_rel,m | 0.43 - | 0.428 - | -0.53 % | Without a restraint: 0.51 |
| k_crit | 1.00 - | 1.000 - | 0.0 % | 1.00 without a restraint as well (λ_rel,m < 0.75) |
| Unity check, stresses (governing) | 0.36 - | 0.361 - | +0.26 % | Technosoft reports (6.17), StruCla (6.11): N ≈ 0, same formula |
5. Stability parameters (50×100, l = 1500 mm)
| Quantity | Technosoft | StruCla | Difference | Note |
|---|---|---|---|---|
| λ_y | 52.0 - | 52.00 - | 0.0 % | |
| λ_z | 103.9 - | 103.90 - | 0.0 % | |
| λ_rel,y | 0.881 - | 0.8810 - | 0.0 % | |
| λ_rel,z | 1.762 - | 1.7620 - | 0.0 % | |
| k_y | 0.946 - | 0.9460 - | 0.0 % | |
| k_z | 2.199 - | 2.1990 - | 0.0 % | |
| k_c,y | 0.774 - | 0.7740 - | 0.0 % | |
| k_c,z | 0.285 - | 0.2850 - | 0.0 % |
6. What differs or is missing
- Combinations: StruCla's standard set covers every kind Technosoft prints: 6.10a, 6.10b, 1.35·G permanent only, 0.9·G, 0.9·G + Q, 0.9·G + ψ0·Q, and the serviceability combinations characteristic, frequent, quasi-permanent and permanent. All values in the table come from that set.
- Technosoft combinations: as printed on sheet 165: BC1 1.22·G, BC2 0.9·G, BC3 1.22·G + 1.35·ψ0·Q (6.10a), BC4 1.08·G + 1.35·Q (6.10b), BC5 0.9·G + 1.35·Q, BC6 0.9·G + 1.35·ψ0·Q, BC7 characteristic, BC8 permanent, BC9 quasi-permanent, BC10 permanent, BC11 frequent, BC12 permanent.
- Creep: StruCla's final deflection for the characteristic combination is G × (1 + k_def) + Q × (1 + ψ2·k_def): 2.68 mm against the 2.7 mm of Technosoft (w1 + w2 + variable part). For the quasi-permanent and permanent combinations everything is multiplied by (1 + k_def) (E0mean,fin), which gives Technosoft's 1.86 and 1.29 mm.
- Lateral restraint: Technosoft prints l_ef = 1100 mm, which corresponds to 1.0 m between lateral restraints (0.9·1000 + 2·100); the printed restraint distances read "0.000;1.000;0.500". It is not clear from the output whether that is an entered restraint or a default, so l_ef = 1100 mm is used in StruCla. It does not change the result: without a restraint StruCla gives l_ef = 1550 mm, σ_m,crit = 93.1 N/mm², λ_rel,m = 0.51 and k_crit = 1.00, the same unity check of 0.36.
- Governing check: Technosoft reports (6.17), tension and bending, because N = 0.01 kN. StruCla reports (6.11), bending. With N ≈ 0 it is the same formula and the same unity check.
- Shear: StruCla also reports the shear check (unity check 0.23, τ = 0.58 N/mm² against f_v,d = 2.46 N/mm²). Technosoft only prints the governing check in this report.
- Second order: Technosoft calculates geometrically non-linear. For this beam without axial force it makes no difference. StruCla calculates linearly here.
- Buckling: Technosoft prints the stability parameters without compression; StruCla gives the same parameters for every timber member (Stability) and runs the buckling check itself only under compression.