Cross-section Solver

The Cross-section Solver provides comprehensive analysis of structural cross-sections, calculating geometric properties, elastic properties, plastic properties, and warping characteristics using the sectionproperties library.

Input Parameters

Most parameters are optional, but enough information must be provided to create a stable structure with:

Both stiffnesses (EA and EI)
Length specification
At least 1-2 supports
At least one strength load case/combination
At least one serviceability load combination

Core Configuration

sectionsData

array

required

Array of section dictionaries following sectionproperties Documentation format with additional ClearCalcs-specific entries.Note: You may see std_* parameters in past examples. These don’t do anything currently and are simply passed through. They were intended for cross-section design linking.

sectionsData[n]['type']

string

required

String describing the section type. Full names from sectionproperties documentation are available, plus abbreviated names.

sectionsData[n]['mirror']

string

Mirror the section about an axis. Options: "x", "y", or "null"

sectionsData[n]['rot']

number

Rotate section counterclockwise by specified degrees. Use null for no rotation.

materialsData

object

Dictionary of material names and their properties.Default: {"default": {"E": 1, "nu": 0, "fy": 1, "color": "#000", "lineWeight": 3}}Properties include:

E: Elastic modulus
nu: Poisson’s ratio
fy: Yield strength
color: Line color
lineWeight: Line weight for display

Analysis Configuration

analysisType

string

default:"none"

Type of analysis to perform:

"none": No analysis (geometry only)
"elastic": Elastic analysis only
"warping": Elastic + warping analysis
"plastic": Elastic + plastic analysis
"frame": Optimized analysis for frame properties
"full": Complete analysis (elastic + warping + plastic)

checkGeom

string

default:"none"

Geometry validity checking:

"check": Issue error messages for problems
"clean": Try to fix geometry issues automatically
"none": No geometry checking

Mesh and Output Configuration

defaultMeshFactor

number

default:"100"

Maximum mesh size = gross area / this factor

meshColor

string

default:"#AAA"

Color for mesh lines in output

meshWeight

integer

default:"1"

Line weight for mesh lines

zeroTol

float

default:"1e-16"

Tolerance below which results are rounded to zero. Engineering applications typically use 1e-6.

lenUnit

string

required

Unit for length outputs. Must be valid mathjs unit (e.g., ‘m’ for SI, ‘ft’ for US)

forceUnit

string

required

Unit for force outputs. Must be valid mathjs unit (e.g., ‘N’ for SI, ‘kip’ for US)

Output Properties

All outputs are accessible via solverRefId.propertyName where solverRefId is your solver’s reference ID.

Always Available (All Analysis Types)

lines

array

All lines making up the cross-section (excluding mesh)

dimensions

array

Default dimensions for cross-section diagrams. Includes all input dimensions.

domain

array

2×2 array of outer domain extents: [[xmin, ymin], [xmax, ymax]]

points

array

n×2 array of all points/nodes: [[x1, y1], [x2, y2], ...]

facets

array

n×2 array of all elements: [[node0, node1], ...]

holes

array

Points located within empty regions

control_points

array

Points located within filled regions

shift

array

Amount by which each geometry was shifted

Elastic Results

Available for elastic, warping, plastic, and full analysis types:

Basic Properties

number

Gross area

cx, cy

number

Centroid location (X, Y coordinates)

rx, ry

number

Radius of gyration about centroidal axes

r11, r22

number

Radius of gyration about principal axes

phi

number

Angle of major principal axis

Stiffness Properties

number

Axial stiffness

EQx, EQy

number

First moment of area about global axes

EIxx, EIyy, EIxy

number

Second moment of area about centroidal axes

EI11, EI22, EI12

number

Second moment of area about principal axes

EIxxg, EIyyg, EIxyg

number

Second moment of area about global axes

Section Moduli

EZxxp, EZxxm

number

Elastic section modulus for positive/negative bending about centroidal X-axis

EZyyp, EZyym

number

Elastic section modulus for positive/negative bending about centroidal Y-axis

EZxx, EZyy

number

Minimum elastic section modulus (min of positive/negative)

EZ11p, EZ11m, EZ22p, EZ22m

number

Elastic section modulus about principal axes

EZ11, EZ22

number

Minimum elastic section modulus about principal axes

Same Stiffness Outputs

When all sections have identical stiffness, additional properties without ‘E’ prefix are available: Qx, Qy, Ixx, Iyy, Ixy, I11, I22, I12, Ixxg, Iyyg, Ixyg, Zxxp, Zxxm, Zyyp, Zyym, Zxx, Zyy, Z11p, Z11m, Z22p, Z22m, Z11, Z22

Plastic Properties

Available for plastic and full analysis types:

cxp, cyp

number

Plastic centroid location

c11p, c22p

number

Plastic centroid location on principal axes

fySxx, fySyy

number

Plastic section modulus about centroidal axes

fyS11, fyS22

number

Plastic section modulus about principal axes

Same Yield Stress Outputs

When all sections have identical yield stress: Sxx, Syy, S11, S22

Warping Properties

Available for warping and full analysis types:

Shear Centers

x0, y0

number

Shear center location

x011, y022

number

Shear center on principal axes

x0t, y0t

number

Taffetz shear center location

Monosymmetry Constants

betaxp, betaxm, betayp, betaym

number

Monosymmetry constants for positive/negative bending about centroidal axes

beta11p, beta11m, beta22p, beta22m

number

Monosymmetry constants about principal axes

Advanced Properties

number

St Venant’s torsion constant

EIw

number

Warping constant

EAsx, EAsy

number

Shear area about centroidal axes

EAs11, EAs22

number

Shear area about principal axes

Same Stiffness Outputs

When all sections have identical stiffness: J, Iw, Asx, Asy, As11, As22

Frame Properties

For analysisType: "frame" - optimized subset for frame analysis:

number

Gross area

phi

number

Angle of major principal axis

number

Axial stiffness

number

St Venant torsion constant

EQx, EQy

number

First moment of area about global axes

EIxx, EIyy, EIxy

number

Second moment of area about centroidal axes

Example Usage

{
  "type": "remote",
  "referenceId": "section_analysis",
  "solver": "crossSection",
  "inputs": {
    "sectionsData": [
      {
        "type": "rectangular",
        "b": 200,
        "h": 300,
        "material": "steel"
      }
    ],
    "materialsData": {
      "steel": {
        "E": 200000,
        "nu": 0.3,
        "fy": 250,
        "color": "#1f77b4",
        "lineWeight": 2
      }
    },
    "analysisType": "full",
    "lenUnit": "mm",
    "forceUnit": "N"
  }
}

Best Practices

Analysis Type Selection: Choose the minimum analysis type needed for your calculations to optimize performance
Unit Consistency: Ensure lenUnit and forceUnit match your template’s unit system
Geometry Validation: Use checkGeom: "clean" for robust geometry handling
Material Properties: Define realistic material properties for accurate results
Mesh Control: Adjust defaultMeshFactor based on section complexity and required accuracy

Performance Considerations

"frame" analysis type is fastest and most reliable for basic frame properties
"full" analysis provides complete results but takes longer
Complex geometries may require geometry cleaning (checkGeom: "clean")
Large defaultMeshFactor values create finer meshes but slower analysis

When using complex geometries, test with checkGeom: "check" first to identify potential issues before using "clean" mode.

Python Solvers

GIS Solvers

Diagrams

Equation Functions

Input Parameters

Core Configuration

Analysis Configuration

Mesh and Output Configuration

Output Properties

Always Available (All Analysis Types)

Elastic Results

Basic Properties

Stiffness Properties

Section Moduli

Same Stiffness Outputs

Plastic Properties

Same Yield Stress Outputs

Warping Properties

Shear Centers

Monosymmetry Constants

Advanced Properties

Same Stiffness Outputs

Frame Properties

Example Usage

Best Practices

Performance Considerations

Python Solvers

GIS Solvers

Diagrams

Equation Functions

​Input Parameters

​Core Configuration

​Analysis Configuration

​Mesh and Output Configuration

​Output Properties

​Always Available (All Analysis Types)

​Elastic Results

​Basic Properties

​Stiffness Properties

​Section Moduli

​Same Stiffness Outputs

​Plastic Properties

​Same Yield Stress Outputs

​Warping Properties

​Shear Centers

​Monosymmetry Constants

​Advanced Properties

​Same Stiffness Outputs

​Frame Properties

​Example Usage

​Best Practices

​Performance Considerations

Input Parameters

Core Configuration

Analysis Configuration

Mesh and Output Configuration

Output Properties

Always Available (All Analysis Types)

Elastic Results

Basic Properties

Stiffness Properties

Section Moduli

Same Stiffness Outputs

Plastic Properties

Same Yield Stress Outputs

Warping Properties

Shear Centers

Monosymmetry Constants

Advanced Properties

Same Stiffness Outputs

Frame Properties

Example Usage

Best Practices

Performance Considerations