30m Steel Warehouse Design in Tekla Structural Designer (Step-by-Step Guide)

Introduction

Designing a steel warehouse is one of the most common real-world structural engineering projects, especially when you work with industrial buildings, logistics centers, workshops, and storage facilities. A 30m span warehouse typically uses a steel portal frame system, where the main rafters and columns resist gravity and lateral loads efficiently.

In this guide, you’ll learn a clear, practical workflow for designing a 30m steel warehouse using Tekla Structural Designer (TSD). We’ll cover the complete process: setting up the project, creating grid lines, modeling portal frames, adding purlins and girts, defining restraints and supports, applying loads, running analysis, and verifying member design.

This article is written for engineers, students, and designers who want a structured approach they can repeat on future warehouse projects.

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Project Overview: 30m Steel Warehouse

Typical structural system

• Main frame: steel portal frames (columns + rafters)
• Secondary members: purlins (roof), girts (walls)
• Stability system: bracing (roof and wall bracing), gable columns, tie members
• Cladding: roof and wall panels (affect loading and diaphragm assumptions)

Common standards (example)

Many warehouse projects use regional design standards (e.g., Eurocode 3 / AISC / local codes). In Tekla Structural Designer, always confirm your chosen code, load combinations, and national annex settings (if applicable).

Step 1: Start the Model (Project Info + Grid)

1) Create a new project

• Set project name, units, and design code
• Define material grades (steel grade, concrete grade if foundations are included)
• Confirm section libraries (UC/UB, IPE/HEA, RHS/SHS, etc.)

2) Define grid lines

• Create longitudinal grid lines (frame spacing / bays)
• Create transverse grid lines (span direction, typically 30m clear span)
• Set building elevations (base level, eaves level, ridge level)

Quick tip

A clean grid makes everything faster: framing, bracing placement, load zones, and member alignment.

Step 2: Model the Portal Frames

1) Choose your portal frame method

In TSD, you can model a portal frame using different workflows (for example: frame tools or member-by-member). Choose a method that keeps frames consistent across bays.

2) Define key geometry

• Span: 30m
• Eaves height (project-dependent)
• Roof pitch (common ranges depend on cladding and drainage)
• Frame spacing (depends on purlin/girt and load efficiency)

3) Assign preliminary sections

Start with realistic trial sections for columns and rafters. You can optimize later after analysis results.

Step 3: Add Purlins, Girts, and Bracing

1) Purlins and girts

• Purlins: support roof sheeting and provide restraint to rafters
• Girts: support wall cladding and restrain columns

Even if you simplify secondary members, you must represent their restraint effect correctly (this impacts buckling checks).

2) Bracing system

• Roof bracing: controls lateral stability and transfers wind loads
• Wall bracing: prevents sway and improves global stability
• Tension-only bracing: common for slender bracing members

3) Gable columns

If your building has gable end walls, include gable columns and ensure load paths for wind at the gable are clear.

Step 4: Supports, End Restraints, and Member Restraints

1) Supports at base

• Pinned base vs fixed base (big impact on frame moments and drift)
• Confirm support stiffness assumptions match foundation design

2) End restraints

End restraints control whether a member end is considered restrained against rotation, lateral movement, or torsion. These settings directly affect buckling length and design capacity.

3) Member restraints

• Restraints from purlins/girts reduce lateral-torsional buckling risk
• Incorrect restraint assumptions can produce unsafe designs or overly conservative designs

Step 5: Apply Loads (Dead, Live, Wind, etc.)

Common warehouse load types

• Dead loads: self-weight, roof sheeting, insulation, services
• Imposed/live loads: roof maintenance load, snow (if applicable)
• Wind loads: pressure/suction on roof and walls, internal pressure
• Equipment loads: suspended loads, cranes (if any)

Load zones matter

For warehouses, wind zones on roof edges and corners are critical. Apply loads using correct zoning and directions.

Combinations

Use the code-defined combinations. Don’t “guess” combinations—let the software generate them under the selected standard.

Step 6: Model Checks Before Analysis

Checklist before you press “Analyze”

• Check member local axis directions (important for loads and design)
• Check intersections and connectivity (no floating members)
• Check materials and section assignment
• Check load directions and magnitudes
• Display local axes and confirm global building directions

Step 7: Analysis Settings + 2nd Order Buckling

1) Analysis type

Steel portal frames are sensitive to stability effects. Consider second-order (P-Delta) effects where required.

2) 2nd order buckling analysis

If your code and project require it, enable second-order analysis/buckling settings in TSD and confirm that imperfections or equivalent effects are treated as per code options.

3) Review analysis results

• Global deflections/drift
• Frame sway behavior
• Member forces (axial, shear, bending, torsion)
• Reactions (for foundation checks)

Step 8: Design & Verification of Members

1) Design main members

• Rafters: check bending, shear, lateral-torsional buckling, combined actions
• Columns: check axial + bending interaction, buckling lengths, base moments

2) Design bracing members

• Check tension capacity (and compression if not tension-only)
• Confirm connections are realistic for forces obtained

3) Optimization loop

A normal workflow is:

1. Start with conservative trial sections
2. Run analysis
3. Check utilization ratios
4. Optimize sections (heavier where needed, lighter where possible)
5. Re-run until stable and efficient

4) Pay attention to serviceability

• Roof deflection limits
• Frame sway limits
• Cladding compatibility (excess movement can damage panels)

Common Mistakes (And How to Avoid Them)

• Wrong restraints: leads to unsafe buckling checks or overly heavy members.
• Wrong load direction: especially wind and local axis confusion.
• Missing bracing load path: structure “works” in model but is unrealistic in reality.
• Ignoring second-order effects: sway frames can be sensitive to P-Delta.
• Not checking serviceability: strength is OK, but deflection is too large.

Vocabulary List (Steel + Tekla Terms)

Structural steel terms

• Portal frame: a rigid frame system (columns + rafters) resisting vertical and lateral loads
• Purlin: secondary roof member supporting sheeting
• Girt: secondary wall member supporting cladding
• Bracing: members that provide stability against lateral loads
• LTB (lateral-torsional buckling): instability in beams under bending
• P-Delta: second-order effect from axial load acting through lateral displacement

Tekla Structural Designer terms

• Grid lines: reference lines used to place members accurately
• Load combinations: code-based combinations of load cases
• Member restraint: definition of lateral/rotational restraint affecting buckling length
• Utilization ratio: how close a member is to its design capacity

Practice Exercises

Exercise 1: Portal frame setup

Create a simple single-bay 30m portal frame. Choose pinned bases first, analyze, then switch to fixed bases. Compare:

• Column base moments
• Rafter moments
• Horizontal drift

Exercise 2: Restraint sensitivity

Run the same model with:

• Conservative restraints (few restraints)
• Realistic restraints (purlins/girts provide restraint)

Compare rafter buckling capacity and utilization.

Exercise 3: Wind load direction check

Apply wind in both main building directions. Verify that global axes and local member axes are consistent and results make sense.

Summary

A 30m steel warehouse design in Tekla Structural Designer becomes straightforward when you follow a repeatable workflow: set project and grid, model portal frames, add secondary members and bracing, define realistic restraints, apply code-based loads, run analysis with appropriate second-order settings, and finally verify/optimize member design.

The biggest “make or break” items are usually: (1) restraints and stability, (2) wind load zoning/directions, and (3) serviceability checks.

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