structural-lib-is456 0.21.6

IS 456 RC Design Library — beams, columns & footings (flexure, shear, axial, ductile detailing, DXF export)

structural-lib-is456

IS 456 RC Beam Design Library (Python package).

Version: 0.21.6 (development preview) Status:

⚠️ Development Preview: APIs may change until v1.0. For reproducible results, pin to a release tag.

Install

pip install structural-lib-is456           # from PyPI
pip install "structural-lib-is456[dxf]"    # with DXF export support

# Or pin to a release tag
pip install "structural-lib-is456 @ git+https://github.com/Pravin-surawase/structural_engineering_lib.git@v0.21.6#subdirectory=Python"

Requires Python 3.11+. On Python 3.9–3.10, pip installs the older v0.16.x (beam-only, no column/footing).

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If You Want To…

Design a Beam (IS 456 flexure + shear)

from structural_lib import design_beam_is456

result = design_beam_is456(
    units="IS456", b_mm=300, D_mm=500, d_mm=450,
    fck_nmm2=25, fy_nmm2=500,
    mu_knm=150, vu_kn=100,
)
print(f"Ast = {result.flexure.Ast_required:.0f} mm²")
print(f"Safe? {result.flexure.is_safe}")

Get Detailing (bar sizes, stirrups, cut lengths)

from structural_lib import build_detailing_input, compute_detailing

detailing_input = build_detailing_input(
    result, beam_id="B1", b_mm=300, D_mm=500, d_mm=450,
    span_mm=6000, cover_mm=30, fck_nmm2=25, fy_nmm2=500,
)
detailed = compute_detailing(detailing_input)

for beam in detailed:
    print(f"{beam.beam_id}: {len(beam.top_bars)} top, {len(beam.bottom_bars)} bottom zones")

Generate a Bar Bending Schedule (BBS)

from structural_lib import compute_bbs

bbs = compute_bbs(detailed, project_name="My Project")
print(f"Total weight: {bbs.summary.total_weight_kg:.1f} kg")
for item in bbs.items:
    print(f"  {item.bar_mark}: ø{item.diameter_mm:.0f} × {item.no_of_bars} nos")

Export DXF Drawings

from structural_lib import compute_dxf

output_path = compute_dxf(detailed, "beam.dxf")  # returns Path
print(f"DXF saved to {output_path}")

Requires the dxf extra: pip install "structural-lib-is456[dxf]"

Generate an HTML Report

from structural_lib import compute_report

html = compute_report(detailing_input, format="html")
with open("report.html", "w") as f:
    f.write(html)

Batch Design from CSV

from structural_lib.services.adapters import GenericCSVAdapter
from structural_lib import design_beam_is456

adapter = GenericCSVAdapter()
geometry_list, forces_list = adapter.load_combined("beams.csv")
# Pair geometry with forces and design each beam
for geom, forces in zip(geometry_list, forces_list):
    result = design_beam_is456(
        units="IS456", b_mm=geom.b_mm, D_mm=geom.D_mm, d_mm=geom.d_mm,
        fck_nmm2=geom.fck_nmm2, fy_nmm2=geom.fy_nmm2,
        mu_knm=forces.mu_knm, vu_kn=forces.vu_kn,
    )
    print(f"Ast = {result.flexure.Ast_required:.0f} mm²")

Run the Full Pipeline (design → detail → BBS → report)

See examples/end_to_end_workflow.py for a complete working script (available in the source repository).

Cost-Optimize a Beam

from structural_lib import optimize_beam_cost

optimized = optimize_beam_cost(
    units="IS456", span_mm=6000, mu_knm=150, vu_kn=100,
)
print(f"Optimal: {optimized.optimal_design.b_mm}×{optimized.optimal_design.D_mm} mm")

Check Multi-Case Compliance

from structural_lib import check_beam_is456

report = check_beam_is456(
    units="IS456", b_mm=230, D_mm=500, d_mm=450,
    fck_nmm2=25, fy_nmm2=500,
    cases=[{"case_id": "ULS-1", "mu_knm": 100, "vu_kn": 80}],
)
print(f"Governing case: {report.governing_case_id}")

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CLI Usage

python -m structural_lib design input.csv -o results.json        # Beam design
python -m structural_lib bbs results.json -o bbs.csv             # Bar bending schedule
python -m structural_lib dxf results.json -o drawings.dxf        # DXF drawings
python -m structural_lib report results.json --format=html -o report.html  # HTML report
python -m structural_lib job job.json -o output/                 # Full job from spec
python -m structural_lib --help                                  # All options

---

What's Available

Beam Design & Detailing

Category	Functions	Description
Beam Design	design_beam_is456, design_and_detail_beam_is456, design_from_input	IS 456 flexure + shear
Detailing	build_detailing_input, compute_detailing, detail_beam_is456	Bar sizes, stirrups, cut lengths
Optimization	optimize_beam_cost, smart_analyze_design, suggest_beam_design_improvements	Cost optimization, smart analysis
Compliance	check_beam_is456, check_compliance_report, check_beam_slenderness, check_beam_ductility	Multi-case IS 456 checks
Torsion	design_torsion, calculate_equivalent_shear, calculate_equivalent_moment, calculate_torsion_shear_stress, calculate_torsion_stirrup_area, calculate_longitudinal_torsion_steel	IS 456 Cl 41 torsion design
Serviceability	check_deflection_span_depth, check_crack_width	Deflection + crack width
Shear	enhanced_shear_strength_is456	Enhanced shear near supports (IS 456 Cl 40.5)
Load Analysis	compute_bmd_sfd	Bending moment & shear force diagrams

Column Design (IS 456 Cl 25, 39.3–39.7)

Category	Functions	Description
Unified Design	design_column_is456	Full column design orchestration
Axial Capacity	design_column_axial_is456	Short column axial capacity (Cl 39.3)
Uniaxial Bending	design_short_column_uniaxial_is456	Short column with uniaxial moment (Cl 39.5)
Biaxial Bending	biaxial_bending_check_is456	Biaxial bending check (Cl 39.6)
Long/Slender Columns	design_long_column_is456, calculate_additional_moment_is456	Slender column design with additional moment (Cl 39.7)
Classification	classify_column_is456, calculate_effective_length_is456, min_eccentricity_is456	Short/slender classification, effective length (Table 28)
Interaction Curve	pm_interaction_curve_is456	P-M interaction diagram generation
Helical Reinforcement	check_helical_reinforcement_is456	Helical reinforcement check (Cl 39.4)
Column Detailing	detail_column_is456	Reinforcement detailing (Cl 26.5.3)

Footing Design (IS 456 Cl 34)

Category	Functions	Description
Sizing	size_footing	Footing plan dimensions from load & SBC
Flexure	footing_flexure	Critical section bending design
One-Way Shear	footing_one_way_shear	One-way shear check at d from face
Punching Shear	footing_punching_shear	Two-way punching shear at d/2 perimeter
Bearing	check_bearing_pressure, bearing_stress_enhancement	Bearing pressure & stress enhancement

IS 13920 Ductile Detailing

Category	Functions	Description
Ductile Detailing	check_column_ductility_is13920	IS 13920 seismic ductile detailing checks

Export, Import & Visualization

Category	Functions	Description
BBS / Export	compute_bbs, export_bbs, compute_dxf, compute_report	BBS, DXF, HTML reports
CSV Import	GenericCSVAdapter (via structural_lib.services.adapters)	40+ column mappings
ETABS Integration	load_etabs_csv, create_job_from_etabs, create_jobs_from_etabs_csv, validate_etabs_csv, normalize_etabs_forces	ETABS CSV import
3D Geometry	beam_to_3d_geometry, compute_rebar_positions, compute_stirrup_positions, compute_beam_outline	3D rebar visualization
Validation	validate_job_spec, validate_design_results, verify_calculation	Input/output validation
Audit	compute_hash, create_calculation_certificate, generate_calculation_report	Calculation audit trail

Full API reference: see docs/reference/api.md

License

MIT — see LICENSE.