structural-lib-is456 0.21.2

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: 0.21.2 (development preview) Status:

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

For full project overview and usage examples, see the repository root README.md.

Install

# Recommended (pinned to release tag)
pip install "structural-lib-is456 @ git+https://github.com/Pravin-surawase/structural_engineering_lib.git@v0.21.2#subdirectory=Python"

# With DXF support (pinned)
pip install "structural-lib-is456[dxf] @ git+https://github.com/Pravin-surawase/structural_engineering_lib.git@v0.21.2#subdirectory=Python"

# PyPI (latest — may differ from pinned tag)
pip install structural-lib-is456

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

Requires Python 3.11+. On Python 3.9–3.10, pip will install the older v0.16.x which has a smaller API (beam-only, no column/footing support).

Extras

• dxf: DXF export support (ezdxf)
• render: planned DXF render to PNG/PDF (matplotlib) — not implemented yet
• dev: tooling for tests/formatting/linting

Quick Start: CLI Usage

The library provides a unified command-line interface:

# Run beam design from CSV input
python -m structural_lib design input.csv -o results.json

# Generate bar bending schedule
python -m structural_lib bbs results.json -o bbs.csv

# Generate DXF drawings (requires ezdxf)
python -m structural_lib dxf results.json -o drawings.dxf

# Run complete job from specification
python -m structural_lib job job.json -o output/

# Critical set + report from job outputs
python -m structural_lib critical output/ --top 10 --format=csv -o critical.csv
python -m structural_lib report output/ --format=html -o report.html

The HTML report includes a cross-section SVG, input sanity heatmap, stability scorecard, and units sentinel.

You can also generate reports directly from design_results.json:

python -m structural_lib report results.json --format=html -o report/ --batch-threshold 80

Run python -m structural_lib --help for more options.

Insights export (v0.13.0+)

python -m structural_lib design input.csv -o results.json --insights
# Writes: results.json + <output_stem>_insights.json

Note: CLI insights currently export precheck + sensitivity + robustness; constructability may be null until CLI integration is completed.

Quick Start: Python API

from structural_lib import flexure, shear, api

# Single beam design
result = flexure.design_singly_reinforced(
    b=230, d=450, d_total=500, mu_knm=100, fck=25, fy=500
)
print(f"Ast required: {result.ast_required:.0f} mm²")

# Multi-case compliance check
report = api.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}")

New in v0.21.0

• Cost Optimization: optimize_beam_cost() for cost-optimized beam design.
• API Contract Testing: check_api.py --signatures for preventing API mismatches.
• Library-first API wrappers: validate_*, compute_detailing, compute_bbs, export_bbs, compute_dxf, compute_report, compute_critical.
• New CLI helpers: validate for schema checks and detail for detailing JSON export.
• DXF/BBS quality gates: mark consistency checks + DXF content tests + title block context.
• Batch packaging (V08): report accepts design results JSON and supports folder output with --batch-threshold.
• Golden fixtures (V09): Deterministic report outputs verified via golden-file tests.