LumoStruct imports LINE entities from AutoCAD DXF files and automatically
creates beam elements. The layer name determines the cross-section profile.
Quick Tip
Layer names define profiles! Use the naming convention below to auto-generate sections.
Layer Naming Convention
Format: PROFILE or PROFILE_PLATEWIDTHxTHICKNESS
Profile Type
Layer Name Format
Example
HP (Holland Profile)
HP[height]x[thickness]
HP200x10
FB (Flat Bar)
FB[height]x[thickness]
FB150x12
T (T-Profile)
T[web_h]x[web_t]+[flange_w]x[flange_t]
T300x10+150x15
With Attached Plate
Add _[width]x[thickness] suffix to include effective plate:
# HP Profile with 600mm × 12mm plateHP200x10_600x12# Flat Bar with 500mm × 10mm plateFB150x12_500x10# T-Profile with 800mm × 14mm plateT300x10+150x15_800x14
Dimension Units
All dimensions in layer names are in millimeters (mm).
AutoCAD drawing units are automatically converted to meters.
Parameter
Unit
Description
Layer dimensions
mm
Profile height, thickness, plate width
DXF coordinates
any
Automatically parsed as meters
Complete Examples
# Transverse stiffeners - HP200×10 with 600mm plateHP200x10_600x12# Longitudinal stiffeners - HP180×10 with 700mm plateHP180x10_700x12# Primary girder - T-profile with 1000mm plateT400x12+200x20_1000x16# Secondary stiffener - Flat bar without plateFB120x10# Unknown layer - defaults to HP200×10MISC_LINES
Important Notes
Only LINE entities are imported (not polylines, arcs, etc.)
Layer names are case-insensitive (HP200x10 = hp200x10)
Use x or X as dimension separator
Unrecognized layers default to HP200×10
Nodes at line endpoints are automatically merged (0.001m tolerance)
AutoCAD Workflow
Create layers with proper naming convention
Draw beam centerlines as LINE entities on appropriate layers
Save as DXF (R12/R14) format for best compatibility
Import into LumoStruct
Profiles will be auto-created in General → Beam Profiles
Import Section Geometry
Import a custom section geometry from DXF file. Supports LINE, POLYLINE, LWPOLYLINE, and REGION entities.
The effective breadth (attached plate) will always be positioned at the top.
Preview (Plate on top)
Section Properties
Area (A)-
Iy (strong axis)-
Iz (weak axis)-
Wy,top-
Wy,bot-
Centroid from top-
Total height-
This name will be used to identify the section in the model.
Import Geometry
Select the structural element type and enter the position data.
mm
Distance from baseline (AB) to deck level
mm
Longitudinal position from AP (Aft Perpendicular)
File:
-
Untitled model
DXF File (.dxf)
Analysis Model (.steel / DNV .xml)
JSON Model (.json)
Recent
DXF Import Guide
General Data
Material Properties
Material
Structural Steel
Grade
E — Young's Modulus210 000N/mm²
fy — Yield Strength235N/mm²
ρ — Density7 850kg/m³
Beam Profiles0
HP Catalog (EN 10067)
or enter manually
b (mm)
t (mm)
h — Height (mm)
t — Thickness (mm)
hweb (mm)
tw (mm)
bf (mm)
tf (mm)
a — Leg 1 (mm)
b — Leg 2 (mm)
t — Thickness (mm)
D — Outer diameter (mm)
t — Wall (mm)
EN 10220 catalog
Circular hollow section. No attached plate.
ℓ — Span (m)
s — Spacing (mm)
tp,net — Plate (mm)
ℓbdg — Bending span (m)
S — Spacing (m)
beff (calculated)500 mm
beff — Width (mm)
tp — Thickness (mm)
tp — Plate Thickness (mm)
Created Profiles:
Name
A (cm²)
Iy (cm⁴)
Wy (cm³)
No profiles created
Model
Generate
Model maintenance
Nodes0
X (mm)
Y (mm)
Z (mm)
ID
X (mm)
Y (mm)
Z (mm)
BC
No nodes
Beams0
Node 1
Node 2
Section
ID
N1
N2
Section
L (mm)
No beams
Sections0
Name
A (cm²)
Iy (cm⁴)
Wy (cm³)
Iz (cm⁴)
Wz (cm³)
No profiles yet — New profile… or import a model
Model Validation
Click "Check" to validate model
Clears all nodes, elements, loads & boundaries
Boundary Conditions
Select nodes in the view and set boundary conditions. Use preset buttons for quick setup.
Current Constraints
Node
Ux
Uy
Uz
Rx
Ry
Rz
No constraints defined
Quick BC Presets
Select nodes first, then click preset
Loads
Define point loads on nodes or distributed loads on beams.
Load case for new loads
Active: L - Live. Each load keeps its case; combinations factor them.
Point Loads
Node
Fx
Fy
Fz (kN)
Mx
My
Mz
Case
No loads defined
Line Loads (Distributed)
Elem
Nodes
q (kN/m)
Range
Case
No line loads defined
Beam Point Loads
Elem
Nodes
P (kN)
Position
Case
No beam point loads (add from the beam panel)
Add Point Load to Selected Node
Fz (kN)
Negative = downward
Add Line Load to Selected Element(s)
q (kN/m)
Direction
Start (%)
End (%)
Positive = downward (global -Z) | Select multiple beams with Ctrl+Click or box select
Pressure Loads (plate → beams)
Name
p (kN/m²)
Patch (m)
Carried by
Case
No pressure loads
Add pressure patch
p (kN/m², + = down)
Carried by
Case
X1 (mm)
X2 (mm)
Z level (mm, blank = all)
Y1 (mm)
Y2 (mm)
Each beam inside the patch gets q = p × tributary width (half-way to its parallel neighbours). "auto" loads the closer-spaced set only, so the load is not counted twice.
Settings
Interface
Text already scales with the window; this is on top of that.
Solver Validation
Tests the solver against 4 classic beam cases (simply supported, fixed-fixed, cantilever) with known analytical solutions. Run after any change that touches the solver to confirm results are still correct.
Material
-
Set on the General tab
Units
Geometry, spans
m
Profile dimensions
mm
Deflection
mm
Forces, reactions
kN
Line loads
kN/m
Pressure
kN/m²
Moments
kN·m
Stress
MPa (N/mm²)
Point load Fz is a component: negative acts downward. Line load q is a magnitude; its direction comes from the
angle - 90° straight down, 0° sideways across the beam.
Reactions are reported upward positive; node coordinates are entered in mm.
Project
Stress Limits
Deflection Limit
Checked per beam against its own span (deflection relative to the beam ends). Common: L/250 – L/300.
Material Library
Grade
E (GPa)
σy (MPa)
A
210
235
AH32
210
315
AH36
210
355
DH36
210
355
Grid Settings
Color Theme
Display Sizes
Geometry
1.0x
1.0x
1.0x
1.0x
Labels
1.0x
1.5x
1.0x
Results
Model Changed
Results are outdated. Click Solve to update.
No results yet.
Generate a model and click Solve.
Diagram Scale:1.0x
Max deflection
-
mm
Max stress σ
-
MPa
Max moment
-
kN·m
Max shear
-
kN
Utilisation
-
%
Equilibrium
-
Slenderness / buckling
-
Deflection
-
Rule Z / Ashr
-
0--
Support Reactions
Node
Fz (kN)
Mx (kNm)
My (kNm)
Mz (kNm)
Top 10 Displacements
Node
Uz (mm)
Steel density 7850 kg/m³, applied along each member
Load Combinations
Current: LC1 |
Factor: 1.0
Section
Zoom100%
Display
Snap
Draw
Edit
Modify
0.4x
50×
Von Mises Stress⋮⋮
- MPa- MPa0 MPa
Max: -
Yield: 355 MPa
Select & Focus
View Details
️ Split Here SP
Split 50%
⫽ Offset O
Join J
Show in 2D — Top (XY)
Show in 2D — Elevation
Copy CO
Move M
Mirror MI
Properties
Delete Del
Select & Focus
View Details
Move Node
Set Coordinates...
Merge Nearby
Add Boundary Condition
Add Load
Undo Ctrl+Z
Redo Ctrl+Y
Draw Line L
Fit View F
XY Plane (Top)Click: select · R-click: menu · Del: delete · F: fit · T: labels · ?: help
X: 0 Y: 0Selection: 0
Properties
Nothing selected
Click a node or beam in the view
Model
Nodes0
Beams0
Total length-
Steel weight-
Profiles0
Supports0
Loaded beams0
Point loads0
Extents-
Results view — read-only. Edit on the Model, Boundary or Loads tab.
Node
ID-
Xmm
Ymm
Zmm
Boundary Condition
Free
Prescribed movement (mm):
X
Y
Z
Only applies to directions that are held.
Loads on Node
Point Load (kN):
Fx
Fy
Fz
Mx (kNm)
My (kNm)
Mz (kNm)
Fz: negative = downward
Results
Uz-
Rx-
Ry-
Beam
ID-
Name
Nodes-
Length-
Node Coordinates (mm)
Start Node
X
Y
End Node
X
Y
Section
Profile-
Grade-
Section Properties
A (Area)-
Strong Axis (Y-Y):
Iy-
Wy-
Weak Axis (Z-Z):
Iz-
Wz-
Effective (with orientation):
I: -W: -
Edit Section
Orientation
0°
Hinges (moment release)
Releases My and Mz at that end; torsion and axial stay connected.
Buckling length factors
Ky (strong)
Kz (weak)
Curve
KLT (lateral)
Compression flange
Rule load model (DNV Tab.1 / BV Tab.3, for the rule Z & Ashr check)
Lcr = K·L, L = span between supports (same-name collinear beams, as in the deflection check). 1.0 pinned-pinned · 0.7 fixed-pinned · 0.5 fixed-fixed · 2.0 cantilever. EN 1993-1-1 6.3.1 flexural buckling, 6.3.2 lateral-torsional buckling (unrestrained open sections, Lcr = KLT·L) and 6.3.3 N+M interaction (Annex B, elastic). See Results › Tables › Buckling.