Input/Output Formats

JSON input

LoadSet.read_json() expects a JSON file matching the Pydantic schema:

{
  "name": "Supplier Forces v1",
  "version": 1,
  "units": {"forces": "N", "moments": "Nm"},
  "loads_type": "limit",
  "load_cases": [
    {
      "name": "Case_A",
      "description": "Full braking at 120 km/h",
      "point_loads": [
        {
          "name": "left_mount",
          "force_moment": {
            "fx": 100.0,
            "fy": -50.0,
            "fz": 0.0,
            "mx": 0.0,
            "my": 0.0,
            "mz": 0.0
          }
        }
      ]
    }
  ]
}

Required fields

• name — load set identifier (string or null)
• version — integer version number
• units — object with forces and moments keys
• load_cases — array of load case objects

Optional fields

• description — free-text description
• loads_type — "limit" or "ultimate" (or null)

You can generate the full JSON Schema programmatically:

from ductile_loads import LoadSet

schema = LoadSet.generate_json_schema(output_file="loadset_schema.json")

ANSYS output (.inp)

to_ansys() generates one .inp file per load case. Each file contains ANSYS APDL commands:

/TITLE,Case_A
nsel,u,,,all

cmsel,s,pilot_left_mount
f,all,fx,1.000e+02
f,all,fy,-5.000e+01
nsel,u,,,all


alls

Format details

• /TITLE,{loadcase_name} — sets the load case name
• cmsel,s,pilot_{point_name} — selects the pilot node for a point
• f,all,{component},{value} — applies a force or moment component
• Only non-zero components are written
• Component order: fx, fy, mx, my, mz, fz
• Point names are automatically prefixed with pilot_
• Values are formatted in scientific notation (3 decimal places)

Reading ANSYS files

To read an existing .inp file back into a LoadSet:

from ductile_loads import LoadSet, Units

ls = LoadSet.read_ansys(
    "design_load_01.inp",
    units=Units(forces="N", moments="Nm"),
    name="Imported loads",
)

Markdown output

envelope_to_markdown() generates a Markdown table:

## Supplier Forces v1 — Envelope Summary

Version: 1 | Units: N, Nm

| Point | Type | FX | FY | FZ | MX | MY | MZ |
|-------|------|-------:|-------:|-------:|-------:|-------:|-------:|
| left_mount | max | 100.0 | 0.000 | 50.0 | 0.000 | 0.000 | 0.000 |
| | min | -20.0 | -50.0 | 0.000 | 0.000 | 0.000 | 0.000 |

Points: 1 | From 5 load cases

JSON extremes output

get_point_extremes() returns (and optionally writes) a nested dictionary:

{
  "left_mount": {
    "fx": {
      "max": {"value": 100.0, "loadcase": "Case_A"},
      "min": {"value": -20.0, "loadcase": "Case_C"}
    },
    "fy": {
      "max": {"value": 0.0, "loadcase": "Case_A"},
      "min": {"value": -50.0, "loadcase": "Case_A"}
    }
  }
}

Components where both max and min are zero are filtered out.