eurocodepy

A Python library for structural design calculations according to the Eurocode standards. eurocodepy provides composable, engineering-focused building blocks — material databases, load combinations, section utilities, and code-compliant design checks — that you can drop into scripts, notebooks, or larger analysis tools.

Documentation: https://pcachim.github.io/eurocodepy/
Source: https://github.com/pcachim/eurocodepy
PyPI: https://pypi.org/project/eurocodepy/
Changelog: https://github.com/pcachim/eurocodepy/blob/master/CHANGELOG.md

What's included

Material databases

Characteristic and design values are stored in a bundled database and surfaced through typed Python classes. Variable names follow standard Eurocode notation (fck, fyd, E0mean, …) so calculations trace directly back to the clauses that define them.

Steel profiles

Standard European hot-rolled profiles are available as dictionaries of dataclasses exposing the catalogue properties (A, Iy, Iz, Wpl_y, IT, Iw, … in cm):

• I-profiles: IPE, HEA, HEB, HEM
• Hollow sections: CHS (circular), RHS (rectangular), SHS (square)

Eurocode modules

Editions and National Annexes

Functions take edition= (the 2004 default, or "2023" for the second-generation Eurocode 2) and annex= (a country code). A National Annex is one JSON file of patches over the recommended values, and register_annex adds your own. Portuguese data (seismic and wind zones, live loads) is bundled; the Portuguese parameters of EN 1992-1-1:2023 are not there yet, so annex="PT" gives the recommended values for concrete. Seismic and wind data of Portuguese municipalities are available through NationalParams, seismic_get_params and wind_get_params.

Calculation reports and units

Most checks take trace= with a CalcReport that records every step with its clause and formula, and exports it as a dictionary or Markdown. eurocodepy.units has unit systems (SI, kN_m, kN_mm, N_mm) used by the force and stress containers of ec1; the calculation functions work in the fixed units given in their documentation.

Quick start

import eurocodepy as ec

# ── Concrete and reinforcement (EN 1992) ───────────────────────────────────
c = ec.Concrete('C30/37')
r = ec.Reinforcement('B500B')
print(c.fck, c.fcd, c.Ecm)           # 30 MPa, 20 MPa, 33 000 MPa
print(r.fyk, r.fyd)                  # 500 MPa, ~434.8 MPa

# The same concrete with the second-generation code: fcd = ηcc·ktc·fck/γc
c23 = ec.ec2.get_concrete('C50/60', edition='2023', loading='other')
print(c23.eta_cc, c23.k_tc, c23.fcd)

# ── Bending and shear of a rectangular beam (EN 1992-1-1:2004) ─────────────
# m, cm², kNm, MPa (see the documentation of each function for its units)
MRd, eps_s, x = ec.ec2.calc_mrd(b=0.30, d=0.46, ast=8.04, fcd=c.fcd, fyd=r.fyd)
from eurocodepy.ec2.uls.shear import calc_vrdc
vrd_min, vrd_c, vrd = calc_vrdc(bw=0.30, d=0.46, fck=30, g_c=1.5, rho_l=0.0117)
print(f"MRd = {MRd:.1f} kNm, VRd,c = {vrd:.1f} kN")

# ── Shear check of EN 1992-1-1:2023, clause 8.2 ─────────────────────────────
from eurocodepy.ec2 import uls2023
shear = uls2023.eurocode2_shear_check(
    uls2023.ShearInput(b=0.3, d=0.5, fck=30, fyk=500, as_long=0.0015), v_ed=150.0)
print(shear.mode, shear.asw_s)       # 'stirrups', Asw/s [m²/m]

# ── Structural steel (EN 1993) ─────────────────────────────────────────────
steel = ec.Steel('S355')
profile = ec.ec3.ProfilesI['IPE300']
print(steel.fyk, profile.A, profile.Iy)      # 355 MPa, cm², cm⁴
check = ec.ec3.section_check_profile(
    profile, steel.fyk, ec.ec3.SectionForces(my_ed=100.0, vz_ed=80.0))
print(f"utilization = {check.utilization:.2f}")

# ── Timber (EN 1995) ───────────────────────────────────────────────────────
from eurocodepy.ec5.materials import SolidTimber, ServiceClass, LoadDuration
timber = SolidTimber('C24')
kmod = timber.k_mod(ServiceClass.SC1, LoadDuration.MediumDuration)
print(timber.fmk, kmod, timber.design_values(ServiceClass.SC1, LoadDuration.MediumDuration)['fmd'])

# ── Load combinations (EN 1990) ────────────────────────────────────────────
from eurocodepy.ec1 import Load, LoadType, Loads
loads = Loads()                      # γ favourable, γ unfavourable, ψ0, ψ1, ψ2
loads.add(Load('G', LoadType.PERMANENT, 1.0, 1.35, 0.0, 0.0, 0.0))
loads.add(Load('Q', LoadType.LIVE,      0.0, 1.50, 0.7, 0.5, 0.3))
loads.add(Load('W', LoadType.WIND,      0.0, 1.50, 0.6, 0.2, 0.0))
for name in loads.get_ULS_combos():
    print(name)

# ── Seismic spectrum (EN 1998, Portuguese NA) ──────────────────────────────
spec = ec.spectrum.get_spectrum_ec8(
    locale='PT', code='PT1', imp_class='II',
    soil='C', zone='1_2', behaviour=3.0,
)
ec.spectrum.draw_spectrum_ec8(spec, show=False)       # show=True opens the window
ec.spectrum.write_spectrum_ec8(spec, filename='spectrum.csv')

# ── Shallow foundation bearing resistance (EN 1997): angles in radians ─────
import numpy as np
from eurocodepy.ec7 import bearing_resistance
Rd = bearing_resistance(Bx=1.5, By=2.0, Hx=20, Hy=0, N=200,
                        phi=np.radians(30.0), gamma=18.0, q=0.0, c=0.0)
print(f"Rd = {Rd:.1f} kPa")                            # bearing stress

# ── Creep coefficient (EN 1992-1-1:2023, Annex B) ──────────────────────────
from eurocodepy.ec2.sls.creep import creep_coef
phi_t = creep_coef(t=18278, t0=28, fcm28=38.0, RH=60, hn=200, t0_T=28, concrete_class='CN')
print(f"φ(50 y, 28 d) = {phi_t:.2f}")

Installation

# Stable release from PyPI
pip install eurocodepy

# With uv (recommended)
uv add eurocodepy

# Latest development version from GitHub
pip install git+https://github.com/pcachim/eurocodepy.git

Requires Python ≥ 3.12.

Documentation

Full documentation — worked tutorials, how-to guides, a page per module and the API reference — is at:

https://pcachim.github.io/eurocodepy/

Contributing

Contributions are welcome. For significant changes please open an issue first to discuss the approach.

1. Fork the repository
2. Create a feature branch: git checkout -b feature/my-feature
3. Commit your changes: git commit -m 'feat: add my feature'
4. Push and open a Pull Request

Please follow the existing code style (enforced by ruff) and include tests where applicable. See CONTRIBUTING_GUIDELINES.md for more detail.

License

GNU Lesser General Public License v3.0 (LGPLv3) — see LICENSE.md and COPYING for the full text.

Disclaimer

This software is intended for educational and research purposes only. It is not a certified engineering tool and must not be used for final structural designs. Always verify calculations against the official Eurocode standards and applicable national annexes, and have final designs reviewed and approved by a qualified structural engineer. The authors assume no liability for design decisions made using this library.

This disclaimer is in addition to, and does not limit, the warranty disclaimer in the LGPLv3 license (see LICENSE.md).

Acknowledgements

Eurocodes and National Annexes are published by CEN and the respective national standards bodies. This project is not affiliated with CEN or any national standards organization.