Eurocode 3 Verification

Benchmarking against SCI P364, Designers' Guide to EN 1993-1-1, EUR 22898 EN, and Worked Examples in EC3 & EC4.

Open Eurocode 3 Calculator

Verification Cases

126

reference comparisons

Avg Difference

0.43%

vs. reference

Check Types

verification categories

Section Types

section families

Methodology

The Eurocode 3 engine implements the requirements of EN 1993-1-1: General rules and rules for buildings. Verification is performed using high-quality benchmarks from Designers' Guide to EN 1993-1-1 Eurocode 3 (Gardner & Nethercot), SCI P364 (Steel Building Design: Worked Examples for Open Sections), Worked Examples in EC3 & EC4, and EUR 22898 EN (Commentary and Worked Examples to EN 1993-1-5).

Cross-section Resistance: Axial, bending, and shear benchmark cases are compared with Section 6.2 reference calculations.
Buckling Resistance: Flexural buckling (6.3.1) and Lateral-Torsional Buckling (6.3.2) benchmark cases are compared with analytical reference calculations.
Combined stability: Implements Annex B (Method 2) for interaction factors k_yy, k_yz, k_zy, k_zz across diverse loading scenarios.

Verification Results

Demand rows compare the engine to a published number. Capacity-policy rows are labelled as a split, not scored as a percent fail.

ID	Description	Section	Expected	Result	Diff %
EC3-01	406x178x54 UB flange class (pure bending) Designers' Guide to EN 1993-1-1, Ex 5.1	406x178x54 UB	Class 1	Class 1	0.00%
EC3-02	406x178x54 UB web class (pure bending) Designers' Guide to EN 1993-1-1, Ex 5.1	406x178x54 UB	Class 1	Class 1	0.00%
EC3-03	406x178x54 UB overall class (pure bending) Designers' Guide to EN 1993-1-1, Ex 5.1	406x178x54 UB	Class 1	Class 1	0.00%
EC3-04	406x178x54 UB flange class (N=300kN) Designers' Guide to EN 1993-1-1, Ex 5.1	406x178x54 UB	Class 1	Class 1	0.00%
EC3-05	406x178x54 UB web class (N=300kN) Designers' Guide to EN 1993-1-1, Ex 5.1	406x178x54 UB	Class 2	Class 2	0.00%
EC3-06	406x178x54 UB overall class (N=300kN) Designers' Guide to EN 1993-1-1, Ex 5.1	406x178x54 UB	Class 2	Class 2	0.00%
EC3-07	254x254x73 UC flange class (pure compression) Designers' Guide to EN 1993-1-1, Ex 6.2	254x254x73 UC	Class 2	Class 2	0.00%
EC3-08	254x254x73 UC overall class Designers' Guide to EN 1993-1-1, Ex 6.2	254x254x73 UC	Class 2	Class 2	0.00%
EC3-09	229x89 Channel flange class Designers' Guide to EN 1993-1-1, Ex 6.4	229x89 Channel	Class 1	Class 1	0.00%
EC3-10	229x89 Channel web class Designers' Guide to EN 1993-1-1, Ex 6.4	229x89 Channel	Class 1	Class 1	0.00%
EC3-11	229x89 Channel overall class Designers' Guide to EN 1993-1-1, Ex 6.4	229x89 Channel	Class 1	Class 1	0.00%
EC3-12	CHS 244.5x10 overall class Designers' Guide to EN 1993-1-1, Ex 6.7	CHS 244.5x10	Class 1	Class 1	0.00%
EC3-13	RHS 200x100x16 flange class Designers' Guide to EN 1993-1-1, Ex 6.9	RHS 200x100x16	Class 1	Class 1	0.00%
EC3-14	RHS 200x100x16 web class Designers' Guide to EN 1993-1-1, Ex 6.9	RHS 200x100x16	Class 1	Class 1	0.00%
EC3-15	RHS 200x100x16 overall class Designers' Guide to EN 1993-1-1, Ex 6.9	RHS 200x100x16	Class 1	Class 1	0.00%
EC3-17	229x89 Channel Vpl,Rd Designers' Guide to EN 1993-1-1, Ex 6.4	229x89 Channel	332 kN	332.1 kN	0.05%
EC3-18	UB 533x210x92 Mc,Rd Designers' Guide to EN 1993-1-1 / SCI P364	UB 533x210x92	649.0 kN·m	649.0 kN·m	0.00%
EC3-20	UB 406x178x74 rho factor (shear-bending) Designers' Guide to EN 1993-1-1, Ex 6.5	UB 406x178x74	0.27	0.274	1.50%
	Rounding of the ρ factor intermediate value — textbook rounds to 2 significant figures mid-calculation, engine retains full precision.
EC3-21	UB 406x178x74 My,V,Rd (Aw per Eq 6.30) Designers' Guide to EN 1993-1-1, Ex 6.5	UB 406x178x74	386.8 kN·m	386.8 kN·m	0.00%
EC3-22	H 305x305x240 Cl.6.2.9 biaxial interaction ratio Designers' Guide to EN 1993-1-1, Ex 6.10	H 305x305x240	0.33	0.339	2.77%
	Textbook rounds reduced plastic moment MN,Rd and interaction terms to 2 significant figures. The engine retains full intermediate precision, leading to a slightly higher biaxial ratio.
EC3-23	UB 457x191x98 n ratio (N/Npl) Designers' Guide to EN 1993-1-1, Ex 6.6	UB 457x191x98	0.477	0.477	0.08%
EC3-24	UB 457x191x98 a parameter Designers' Guide to EN 1993-1-1, Ex 6.6	UB 457x191x98	0.395	0.395	0.10%
EC3-25	UB 457x191x98 MN,y,Rd Designers' Guide to EN 1993-1-1, Ex 6.6	UB 457x191x98	342.2 kN·m	342.2 kN·m	0.01%
EC3-26	CHS 244.5x10 radius of gyration i Designers' Guide to EN 1993-1-1, Ex 6.7	CHS 244.5x10	82.97 mm	82.97 mm	0.01%
EC3-27	CHS 244.5x10 λ_bar Designers' Guide to EN 1993-1-1, Ex 6.7	CHS 244.5x10	0.56	0.555	0.83%
EC3-28	CHS 244.5x10 χ (curve a) Designers' Guide to EN 1993-1-1, Ex 6.7	CHS 244.5x10	0.91	0.906	0.42%
EC3-29	CHS 244.5x10 Nb,Rd Designers' Guide to EN 1993-1-1, Ex 6.7	CHS 244.5x10	1836.5 kN	1836.5 kN	0.00%
EC3-30	CHS 244.5x10 buckling ratio (NEd=1630 kN) Designers' Guide to EN 1993-1-1, Ex 6.7	CHS 244.5x10	0.888	0.888	0.00%
EC3-31	H 305x305x240 iy Designers' Guide to EN 1993-1-1, Ex 6.10	H 305x305x240	144.86 mm	144.85 mm	0.01%
EC3-32	H 305x305x240 λ_bar_y Designers' Guide to EN 1993-1-1, Ex 6.10	H 305x305x240	0.23	0.234	1.65%
	Textbook rounds λ̄ to 2 decimal places. Engine retains full precision from section property calculations.
EC3-33	H 305x305x240 χ_y (curve b) Designers' Guide to EN 1993-1-1, Ex 6.10	H 305x305x240	0.99	0.988	0.20%
EC3-34	H 305x305x240 iz Designers' Guide to EN 1993-1-1, Ex 6.10	H 305x305x240	81.46 mm	81.47 mm	0.01%
EC3-35	H 305x305x240 λ_bar_z Designers' Guide to EN 1993-1-1, Ex 6.10	H 305x305x240	0.59	0.594	0.65%
EC3-36	H 305x305x240 χ_z (curve c) Designers' Guide to EN 1993-1-1, Ex 6.10	H 305x305x240	0.79	0.789	0.12%
EC3-37	RHS 200x100x16 iy Designers' Guide to EN 1993-1-1, Ex 6.9	RHS 200x100x16	66.56 mm	66.57 mm	0.01%
EC3-38	RHS 200x100x16 λ_bar_y Designers' Guide to EN 1993-1-1, Ex 6.9	RHS 200x100x16	1.42	1.416	0.31%
EC3-39	RHS 200x100x16 χ_y (curve a) Designers' Guide to EN 1993-1-1, Ex 6.9	RHS 200x100x16	0.41	0.410	0.10%
EC3-40	RHS 200x100x16 iz Designers' Guide to EN 1993-1-1, Ex 6.9	RHS 200x100x16	37.17 mm	37.17 mm	0.01%
EC3-41	RHS 200x100x16 λ_bar_z Designers' Guide to EN 1993-1-1, Ex 6.9	RHS 200x100x16	0.84	0.845	0.59%
EC3-42	RHS 200x100x16 χ_z (curve a) Designers' Guide to EN 1993-1-1, Ex 6.9	RHS 200x100x16	0.77	0.769	0.12%
EC3-43	UC 203x203x46 λ_bar_y Worked Examples in EC3 & EC4	UC 203x203x46	0.65	0.653	0.46%
EC3-44	UC 203x203x46 χ_y (curve b) Worked Examples in EC3 & EC4	UC 203x203x46	0.81	0.810	0.05%
EC3-45	UC 203x203x46 λ_bar_z Worked Examples in EC3 & EC4	UC 203x203x46	0.56	0.561	0.24%
EC3-46	UC 203x203x46 χ_z (curve c) Worked Examples in EC3 & EC4	UC 203x203x46	0.81	0.808	0.24%
EC3-47	UB 762x267x173 Mcr Segment CD Designers' Guide to EN 1993-1-1	UB 762x267x173	4311 kN·m	4311 kN·m	0.01%
EC3-48	UB 762x267x173 λ_LT Segment CD Designers' Guide to EN 1993-1-1	UB 762x267x173	0.63	0.629	0.13%
EC3-49	UB 762x267x173 χ_LT Segment CD (general) Designers' Guide to EN 1993-1-1	UB 762x267x173	0.82	0.822	0.26%
EC3-50	UB 762x267x173 λ_LT Segment BC Designers' Guide to EN 1993-1-1	UB 762x267x173	0.55	0.547	0.54%
EC3-51	UB 762x267x173 χ_LT Segment BC (general) Designers' Guide to EN 1993-1-1	UB 762x267x173	0.86	0.863	0.32%
EC3-52	UB 762x267x173 Mb,Rd Segment BC Designers' Guide to EN 1993-1-1	UB 762x267x173	1469 kN·m	1471 kN·m	0.10%
EC3-53	UB 457x191x82 λ_LT Designers' Guide to EN 1993-1-1	UB 457x191x82	0.64	0.641	0.20%
EC3-54	UB 457x191x82 χ_LT (general) Designers' Guide to EN 1993-1-1	UB 457x191x82	0.82	0.816	0.51%
EC3-55	UB 457x191x82 Mb,Rd Designers' Guide to EN 1993-1-1	UB 457x191x82	411 kN·m	411 kN·m	0.06%
EC3-56	UC 203x203x46 Cl.6.3.3 ratio (Annex B) Worked Examples in EC3 & EC4	UC 203x203x46	0.51	0.503	1.37%
	Interaction factors kyy, kzy computed with full precision vs textbook's 2 d.p. rounding of intermediate χ and λ̄ values.
EC3-57	H 305x305x240 Cl.6.3.3 ratio (Annex B) Designers' Guide to EN 1993-1-1, Ex 6.10	H 305x305x240	0.97	0.967	0.34%
EC3-58	RHS 200x100x16 Cl.6.3.3 ratio (Annex B) Designers' Guide to EN 1993-1-1, Ex 6.9	RHS 200x100x16	0.94	0.947	0.73%
EC3-62	533x210x92 UKB shear area Av SCI P364, Example 2	533x210x92 UKB	5723.6 mm²	5723.6 mm²	0.00%
EC3-63	533x210x92 UKB Vpl,Rd SCI P364, Example 2	533x210x92 UKB	909 kN	909 kN	0.03%
EC3-64	533x210x92 UKB VEd/Vc,Rd SCI P364, Example 2	533x210x92 UKB	0.297	0.297	0.03%
EC3-66	533x210x92 UKB MEd/Mc,Rd SCI P364, Example 2	533x210x92 UKB	0.831	0.831	0.00%
EC3-70	457x191x67 Av SCI P364, Example 3	457x191x67 UKB	4093.57 mm²	4093.57 mm²	0.00%
EC3-71	457x191x67 Vpl,Rd SCI P364, Example 3	457x191x67 UKB	650 kN	650 kN	0.01%
EC3-72	457x191x67 Mc,Rd SCI P364, Example 3	457x191x67 UKB	404.25 kN·m	404.25 kN·m	0.00%
EC3-73	457x191x67 Mcr uniform SCI P364, Example 3	457x191x67 UKB	134.2 kN·m	133.7 kN·m	0.37%
EC3-74	457x191x67 Mcr with C1=2.65 SCI P364, Example 3	457x191x67 UKB	355.7 kN·m	354.2 kN·m	0.42%
EC3-75	457x191x67 λ_LT SCI P364, Example 3	457x191x67 UKB	1.07	1.068	0.19%
EC3-76	457x191x67 χ_LT base SCI P364, Example 3	457x191x67 UKB	0.60	0.598	0.27%
EC3-77	457x191x67 f factor SCI P364, Example 3	457x191x67 UKB	0.83	0.833	0.37%
EC3-78	457x191x67 χ_LT,mod SCI P364, Example 3	457x191x67 UKB	0.72	0.718	0.24%
EC3-79	457x191x67 Mb,Rd SCI P364, Example 3	457x191x67 UKB	291 kN·m	290.4 kN·m	0.22%
EC3-80	457x191x67 MEd/Mb,Rd SCI P364, Example 3	457x191x67 UKB	0.89	0.896	0.61%
EC3-81	305x305x97 UKC flange class SCI P364, Example 5	305x305x97 UKC	Class 3	Class 3	0.00%
EC3-82	305x305x97 UKC web class SCI P364, Example 5	305x305x97 UKC	Class 1	Class 1	0.00%
EC3-83	305x305x97 UKC overall class SCI P364, Example 5	305x305x97 UKC	Class 3	Class 3	0.00%
EC3-84	305x305x97 Av SCI P364, Example 5	305x305x97 UKC	3517.38 mm²	3517.38 mm²	0.00%
EC3-85	305x305x97 Vpl,Rd SCI P364, Example 5	305x305x97 UKC	721 kN	721 kN	0.01%
EC3-86	305x305x97 Mc,Rd (elastic, Class 3) SCI P364, Example 5	305x305x97 UKC	514.75 kN·m	514.75 kN·m	0.00%
EC3-87	305x305x97 MEd/Mc,Rd SCI P364, Example 5	305x305x97 UKC	0.641	0.641	0.00%
EC3-88	305x305x97 Mcr uniform SCI P364, Example 5	305x305x97 UKC	460.5 kN·m	461.4 kN·m	0.20%
EC3-89	305x305x97 Mcr with C1=1.32 SCI P364, Example 5	305x305x97 UKC	607.7 kN·m	609.1 kN·m	0.23%
EC3-90	305x305x97 λ_LT SCI P364, Example 5	305x305x97 UKC	0.92	0.919	0.08%
EC3-91	305x305x97 χ_LT base SCI P364, Example 5	305x305x97 UKC	0.74	0.749	1.15%
	Engine uses continuous LTB curve formula; textbook rounds intermediate Φ_LT to 2 d.p.
EC3-92	305x305x97 χ_LT,mod SCI P364, Example 5	305x305x97 UKC	0.79	0.799	1.14%
	Cascading from EC3-91: textbook rounds Φ_LT to 2 d.p., propagating through to χ_LT,mod.
EC3-93	305x305x97 Mb,Rd SCI P364, Example 5	305x305x97 UKC	407 kN·m	411 kN·m	1.05%
	Cascading from χ_LT,mod precision difference (EC3-91/92). Engine gives a slightly higher Mb,Rd.
EC3-94	305x305x97 MEd/Mb,Rd SCI P364, Example 5	305x305x97 UKC	0.81	0.802	0.94%
EC3-95	356x368x129 UKC flange class SCI P364, Example 9	356x368x129 UKC	Class 3	Class 3	0.00%
EC3-96	356x368x129 UKC overall class SCI P364, Example 9	356x368x129 UKC	Class 3	Class 3	0.00%
EC3-97	356x368x129 Nc,Rd SCI P364, Example 9	356x368x129 UKC	5658 kN	5658 kN	0.00%
EC3-98	356x368x129 NEd/Nc,Rd SCI P364, Example 9	356x368x129 UKC	0.619	0.619	0.00%
EC3-99	356x368x129 λ_bar_z SCI P364, Example 9	356x368x129 UKC	0.82	0.821	0.11%
EC3-100	356x368x129 χ_z SCI P364, Example 9	356x368x129 UKC	0.65	0.649	0.15%
EC3-101	356x368x129 Nb,Rd SCI P364, Example 9	356x368x129 UKC	3678 kN	3672 kN	0.16%
EC3-102	356x368x129 buckling ratio SCI P364, Example 9	356x368x129 UKC	0.952	0.953	0.16%
EC3-103	305x305x97 λ_bar_y SCI P364, Example 10	305x305x97 UKC	0.516	0.516	0.05%
EC3-104	305x305x97 χ_y SCI P364, Example 10	305x305x97 UKC	0.87	0.877	0.82%
EC3-105	305x305x97 Nb,y,Rd SCI P364, Example 10	305x305x97 UKC	2943 kN	2967 kN	0.82%
EC3-106	305x305x97 λ_bar_z SCI P364, Example 10	305x305x97 UKC	0.449	0.449	0.05%
EC3-107	305x305x97 χ_z SCI P364, Example 10	305x305x97 UKC	0.88	0.871	1.00%
	Engine uses continuous buckling curve c formula; textbook rounds intermediate Φ to 2 d.p.
EC3-108	457x191x82 Vpl,Rd SCI P364, Example 4	457x191x82 UKB	756 kN	756 kN	0.03%
EC3-109	457x191x82 χ_LT,mod (6.3.2.3 rolled) SCI P364, Example 4	457x191x82 UKB	0.92	0.882	4.15%
	Engine uses the NCCI SN003 closed-form Mcr formula (standard analytical method). The reference derives Mcr from a numerical lateral-torsional buckling model, which yields ~4% lower λ_LT for this section. The analytical result is conservative (safe side).
EC3-110	457x191x82 Mb,Rd SCI P364, Example 4	457x191x82 UKB	463 kN·m	444 kN·m	4.10%
	Cascading from Mcr method difference above. Engine uses NCCI SN003 analytical Mcr; the reference uses a numerical lateral-torsional buckling model. Result is conservative (safe side).
EC3-111	203x203x46 χ_y SCI P364, Example 11	203x203x46 UKC	0.80	0.810	1.20%
	Textbook rounds intermediate Φ to 2 d.p. in buckling curve b; engine retains full precision.
EC3-112	203x203x46 χ_z SCI P364, Example 11	203x203x46 UKC	0.47	0.472	0.49%
EC3-113	203x203x46 χ_LT SCI P364, Example 11	203x203x46 UKC	0.83	0.846	1.93%
	Engine’s SCI/NCCI C1 polynomial approximation overestimates C1 for this moment diagram, yielding a lower λ_LT (0.725 vs reference 0.76 from its numerical Mcr model) and higher χ_LT. The structural interaction ratio remains within 1.6% of the reference.
EC3-114	203x203x46 Cl.6.3.3 combined ratio SCI P364, Example 11	203x203x46 UKC	0.98	0.996	1.59%
	Combined cascading effect from χ_y (EC3-111) and χ_LT (EC3-113) C1 approximation differences.
EC3-115	457x191x67 χ_y (S355) SCI P364, Example 12	457x191x67 UKB	0.94	0.946	0.66%
EC3-116	457x191x67 χ_z (S355) SCI P364, Example 12	457x191x67 UKB	0.62	0.627	1.14%
	Textbook rounds intermediate Φ to 2 d.p. in buckling curve b; engine retains full precision.
EC3-117	457x191x67 χ_LT (S355, Class 3) SCI P364, Example 12	457x191x67 UKB	0.88	0.825	6.24%
	Engine uses NCCI SN003 analytical Mcr with fork support (free warping) at each 3m segment. The reference uses a numerical model with warping continuity at the intermediate restraint, giving a higher Mcr. Lower χ_LT = lower capacity prediction = conservative (safe side).
EC3-118	457x191x67 Cl.6.3.3 combined ratio (Class 3) SCI P364, Example 12	457x191x67 UKB	0.88	0.934	6.11%
	Cascading from χ_LT difference above. Engine’s analytical Mcr (fork support) vs the reference numerical model with warping continuity propagates into the 6.3.3 interaction factors. Result is conservative (safe side).
EC3-119	EUR 22898 §16: Panel I plate slenderness (450×12, S355) EUR 22898 EN, §16 (pp.182)	Plate panel 450×12	0.811	0.812	0.06%
EC3-120	EUR 22898 §16: Panel I reduction factor ρ EUR 22898 EN, §16 (pp.182)	Plate panel 450×12	0.899	0.898	0.08%
EC3-121	EUR 22898 §16: Panel III plate slenderness (288×6, S355) EUR 22898 EN, §16 (pp.182)	Plate panel 288×6	1.038	1.039	0.06%
EC3-122	EUR 22898 §16: Panel III reduction factor ρ EUR 22898 EN, §16 (pp.182)	Plate panel 288×6	0.759	0.759	0.02%
EC3-123	EUR 22898 §15: Bottom flange plate slenderness (700×26, S420) EUR 22898 EN, §15 (pp.174-178)	Plate panel 700×26	0.63	0.634	0.58%
EC3-124	EUR 22898 §15: Stiffener plate slenderness (350×8, S420) EUR 22898 EN, §15 (pp.174-178)	Plate panel 350×8	1.03	1.030	0.03%
EC3-125	EUR 22898 §15: Stiffener reduction factor ρ EUR 22898 EN, §15 (pp.174-178)	Plate panel 350×8	0.763	0.764	0.09%
EC3-126	EUR 22898 §15: Inclined web plate slenderness (391×8, S420) EUR 22898 EN, §15 (pp.174-178)	Plate panel 391×8	1.15	1.150	0.03%
EC3-127	EUR 22898 §15: Inclined web reduction factor ρ EUR 22898 EN, §15 (pp.174-178)	Plate panel 391×8	0.703	0.703	0.01%
EC3-128	EUR 22898 §15: kσ for web ψ=−1.30 (Table 4.1) EN 1993-1-5 Table 4.1 (kσ = 5.98(1−ψ)² for ψ < −1)	EN 1993-1-5 Table 4.1	31.63	31.63	0.00%
	EUR 22898 EN p.178 uses an approximate formula giving kσ=32.5; the correct Table 4.1 formula gives 31.63.
EC3-129	EUR 22898 §15: ρ web bending at λp=1.07, ψ=−1.30 EUR 22898 EN, §15 (p.178)	Plate panel (bending)	0.853	0.853	0.01%
EC3-130	EUR 22898 Eq 4.1: ρ internal λp=2.0 ψ=1 EUR 22898 EN, Eq 4.1 (pp.46-47)	EN 1993-1-5 Eq 4.1	0.445	0.445	0.00%
EC3-131	EUR 22898 Eq 4.2: ρ outstand λp=1.5 EUR 22898 EN, Eq 4.2 (pp.46-47)	EN 1993-1-5 Eq 4.2	0.583	0.583	0.02%
EC3-132	EUR 22898 §15.2: Stiffener ρ at λp=0.857 EUR 22898 EN, §15.2 (p.177)	Plate panel (stiffener)	0.868	0.867	0.08%
EC3-133	254x254x73 UC Compression Resistance Nc,Rd (S355) Designers' Guide to EN 1993-1-1, Ex 6.2	254x254x73 UC	3305 kN	3305.1 kN	0.00%
EC3-134	CHS 244.5x10 Section Compression Npl,Rd (S275) Designers' Guide to EN 1993-1-1, Ex 6.7	CHS 244.5x10	2026.75 kN	2025.9 kN	0.04%
EC3-135	RHS 200x100x16 Bending Resistance Mc,Rd (S355, Class 1) Designers' Guide to EN 1993-1-1, Ex 6.9	RHS 200x100x16	174.3 kN·m	174.3 kN·m	0.00%

Disclaimer: This verification page is provided for informative purposes only and does not constitute a guarantee of accuracy for all possible configurations. While we use automated verification checks to help find defects, no software is entirely free of defects. Engineers must exercise independent professional judgement and verify results through their own checks before relying on any output for design or construction decisions. AutoCalcs accepts no liability for errors, omissions, or any consequences arising from the use of this software.