Castellated Cellular Design

Document Structure

This skill provides access to comprehensive castellated and cellular beam design documentation:

1. Chapter 1: Introduction

Location: data/design-guide/Chapter_1_Introduction.md

Purpose: Understand what castellated and cellular beams are - history, manufacturing, nomenclature

Contents:

• 1.1 History: Evolution from castellated (1910s) to cellular (1980s) beams
• 1.2 Manufacturing Methods: Cutting patterns, expansion ratios, fabrication techniques
  • Castellated: Hexagonal cutting pattern with 60° angles
  • Cellular: Circular cutting pattern with CNC precision
• 1.3 Nomenclature and Geometry:
  • CB (Castellated Beam) terminology: dg (depth), e (expansion ratio), s (spacing), a (hole width)
  • LB (Long-span/Cellular Beam) terminology: do (opening diameter), So (center-to-center spacing)
  • Tee sections, web posts, top and bottom chords

2. Chapter 2: Use Cases and Applications

Location: data/design-guide/Chapter_2_Use_Cases.md

Purpose: Learn when and why to use castellated/cellular beams

Topics:

• 2.1 Typical Applications: Parking garages, residential buildings, commercial buildings
• 2.2 Advantages:
  • Increased depth without added weight (20-50% depth increase)
  • MEP integration through openings
  • Material efficiency, architectural appeal
• 2.3 Special Considerations:
  • Deflection reduction (90% effective Ix)
  • Complex failure modes (Vierendeel, web post buckling)
  • Fabrication costs vs material savings
  • Composite vs noncomposite behavior

3. Chapter 3: Design Procedures

Location: data/design-guide/Chapter_3_Design_Procedures.md

Purpose: How to design - formulas, procedures, limit states

Sections:

• 3.1 General Principles: Limit states, LRFD and ASD methods, AISC Specification integration
• 3.2 Flexural Strength:
  • Vierendeel mechanism (unique to web openings)
  • Moment redistribution, plastic hinge formation
• 3.3 Web Post Buckling:
  • Critical spacing criteria
  • Slenderness limits (h/tw, s/h ratios)
  • Elastic and inelastic buckling
• 3.4 Shear Strength:
  • Tee section shear capacity
  • Web post shear resistance
• 3.5 Lateral-Torsional Buckling: Modified procedures for reduced Iy
• 3.6 Deflection:
  • Effective moment of inertia (Ieff ≈ 0.9 Ix)
  • Vierendeel deformation effects
  • Simplified calculation methods
• 3.7 Composite Action: Interaction with concrete slab, shear connector design
• 3.8 Special Checks: End reactions, connection design, opening reinforcement

4. Design Examples (Chapter 4)

Location: data/examples/

Purpose: See worked examples with complete step-by-step calculations

Examples:

• Example 4.1: Noncomposite Castellated Beam (CB)

  • File: Example_4-1_Noncomposite_Castellated.md
  • Given beam, determine capacity
  • All limit states checked (Vierendeel, web post, shear, LTB, deflection)

• Example 4.2: Noncomposite Cellular Beam (LB)

  • File: Example_4-2_Noncomposite_Cellular.md
  • Circular openings vs hexagonal
  • Geometry differences highlighted

• Example 4.3: Composite Castellated Beam (CB)

  • File: Example_4-3_Composite_Castellated.md
  • Concrete slab interaction
  • Positive moment region design

• Example 4.4: Composite Cellular Beam (LB)

  • File: Example_4-4_Composite_Cellular.md
  • Full composite action
  • Deflection calculations with composite properties

Key Distinction:

• Chapter 1 → "What is a castellated/cellular beam?" "How are they made?"
• Chapter 2 → "When should I use them?" "What are the advantages?"
• Chapter 3 → "How do I design them?" "What formulas do I use?"
• Examples → "Show me a complete calculation step-by-step"

Reference Files

This skill includes comprehensive reference materials:

• references/symbols.md: Complete symbols table (mathematical notation for DG31)
• references/glossary.md: Technical terms and definitions (Vierendeel, web post, etc.)
• references/abbreviations.md: CB, LB, DG31, AISC, LRFD, ASD, etc.
• references/examples-index.md: Complete example index (4 examples with cross-references)
• references/failure-modes-guide.md: Quick reference for all failure modes (Vierendeel, web post, shear, LTB)
• references/geometry-guide.md: Geometric relationships and calculation formulas (CB vs LB)
• references/design-workflow-summary.md: Step-by-step design process flowchart
• references/bibliography.md: Research papers, historical references, AISC publications

Automation Scripts

Python scripts are available in scripts/ directory:

• smart_search.py: Category-aware keyword search (planned)
• formula_finder.py: Extract formulas with context (planned)
• example_matcher.py: Match user queries to appropriate examples (planned)
• geometry_calculator.py: CB/LB geometry calculations (opening sizes, spacing, depths) (planned)
• vierendeel_calculator.py: Vierendeel moment and stress calculations (planned)
• web_post_checker.py: Web post buckling verification (planned)

Workflow by Query Type

1. Formula Query (공식 질의)

User Intent: Find a specific formula or equation from AISC Design Guide 31.

Example Queries:

• "What is the formula for Vierendeel moment in castellated beams?"
• "Show me the web post buckling equation"
• "허니컴보의 비렌딜모멘트 공식을 알려줘"
• "웹포스트 좌굴 검토식은?"

Quick Process:

1. Identify topic (Vierendeel → Section 3.2, web post → Section 3.3, deflection → Section 3.6, etc.)
2. Grep relevant section in data/design-guide/Chapter_3_Design_Procedures.md
3. Extract formula with variable definitions from references/symbols.md
4. Note beam type dependency: Check if formula differs for CB vs LB
5. Note composite vs noncomposite: Different formulas may apply
6. Present with AISC DG31 citation (e.g., "AISC Design Guide 31, Section 3.2")

Keywords: formula, equation, 공식, 계산식, expression

2. Design Example Query (예제 질의)

User Intent: See a step-by-step worked example of a castellated or cellular beam design.

Example Queries:

• "Show me how to design a castellated beam"
• "I need an example of cellular beam design with composite action"
• "허니컴보 설계 예제를 보여줘"
• "합성 셀룰러보 계산 과정은?"

Quick Process:

1. Check references/examples-index.md for example number
2. Identify appropriate example:
   • Example 4.1: Noncomposite Castellated (CB)
   • Example 4.2: Noncomposite Cellular (LB)
   • Example 4.3: Composite Castellated (CB)
   • Example 4.4: Composite Cellular (LB)
3. Read from corresponding file in data/examples/
4. Present step-by-step with complete calculations
5. Note specific considerations:
   • Opening geometry (hexagonal vs circular)
   • Composite action (if applicable)
   • All limit states checked

Keywords: example, 예제, how to, step-by-step, 설계과정, worked example

3. Calculation Query (계산 질의)

User Intent: Perform structural calculations using AISC DG31 formulas.

Example Queries:

• "Calculate Vierendeel moment: W16x26 castellated, e=1.5, span=30ft"
• "Check web post buckling: spacing=18in, height=24in, tw=0.25in"
• "캐스텔레이티드보 W18x35, 확장비 1.4, 처짐을 계산해줘"
• "웹포스트 좌굴 검토: 간격 450mm, 높이 600mm"

Quick Process:

1. Identify beam type - CB (castellated) or LB (cellular)
2. Identify composite action - composite or noncomposite
3. Gather geometry:
   • Parent section (W-shape)
   • Expansion ratio (e) or opening diameter (do)
   • Spacing (s or So)
   • Span length (L)
4. Find formula from Chapter 3 (use Formula Query workflow)
5. Find similar example from Chapter 4 for methodology
6. Generate Python code following example structure
7. Execute and validate against AISC DG31 limits

Critical Checks:

• ✅ Beam type specified (CB or LB)
• ✅ Composite action clarified
• ✅ Opening geometry defined (hexagonal or circular)
• ✅ Spacing verified (not too close → web post buckling)
• ✅ Deflection reduction applied (Ieff ≈ 0.9 Ix)
• ✅ All failure modes checked (Vierendeel, web post, shear, LTB)

Keywords: calculate, compute, determine, 계산, 산정, 구해줘, check, verify

4. Geometry/Nomenclature Query (기하학/용어 질의)

User Intent: Understand geometric relationships and terminology for castellated/cellular beams.

Example Queries:

• "What is the expansion ratio for castellated beams?"
• "How do you calculate the expanded depth dg?"
• "Explain web post geometry"
• "확장비가 뭐야?"
• "웹포스트 높이를 어떻게 구하나요?"

Quick Process:

1. Check references/geometry-guide.md for quick reference
2. Check references/glossary.md for term definitions
3. If not found, search Chapter 1.3 (Nomenclature) in Chapter_1_Introduction.md
4. Present definition with diagram references
5. Distinguish CB vs LB geometry:
   • CB (Castellated): hexagonal, expansion ratio (e), opening width (a), height (ho)
   • LB (Cellular): circular, opening diameter (do), center spacing (So)
6. Provide calculation formulas from geometry-guide.md

Common Geometric Terms:

• e (expansion ratio): Typical 1.3-1.5 for CB, ratio of final depth to parent depth
• dg (expanded depth): dg = e × d (parent depth)
• s (spacing): Center-to-center distance between openings
• do (opening diameter): For cellular beams (LB)
• Web post: Solid portion between openings (critical for buckling)
• Tee sections: Top and bottom chords formed by cutting

Keywords: geometry, nomenclature, expansion ratio, 기하학, 형상, 확장비, web post, opening

5. Comparison Query (비교 질의)

User Intent: Compare castellated vs cellular, or composite vs noncomposite designs.

Example Queries:

• "Castellated vs cellular beams - which should I use?"
• "Compare composite and noncomposite cellular beams"
• "허니컴보와 셀룰러보의 차이는?"
• "합성보와 비합성보 중 어느 것이 유리한가?"

Quick Process:

1. Identify comparison type:
   • CB vs LB (beam type)
   • Composite vs noncomposite (slab interaction)
   • Opening shapes (hexagonal vs circular)
2. Search Chapter 2 for advantages/disadvantages
3. Use references/geometry-guide.md for geometric differences
4. Present in comparison table format
5. Reference examples for practical context

CB (Castellated) vs LB (Cellular) Comparison:

Composite vs Noncomposite Comparison:

Keywords: compare, difference, vs, 차이, 비교, advantage, disadvantage

6. Failure Mode Query (파괴모드 질의)

User Intent: Understand failure mechanisms specific to castellated/cellular beams.

Example Queries:

• "What is Vierendeel bending?"
• "Explain web post buckling"
• "What failure modes do I need to check for honeycomb beams?"
• "비렌딜굽힘이 뭐야?"
• "웹포스트 좌굴은 왜 중요한가요?"

Quick Process:

1. Check references/failure-modes-guide.md for quick reference
2. Search Chapter 3 for detailed design procedures
3. Present failure mode with:
   • Mechanism description
   • Why it's unique to web openings
   • Design check procedure
   • Formula reference
4. Cross-reference to examples showing the check

Critical Failure Modes for CB/LB:

1. Vierendeel Bending (Section 3.2):

   • Mechanism: Local moments at opening corners due to shear transfer across opening
   • Unique to: Beams with web openings (no continuous web to resist shear)
   • Check: Combined stress at tee sections (flange + Vierendeel moment)
   • Formula: MV = V × eT (Vierendeel moment from shear)

2. Web Post Buckling (Section 3.3):

   • Mechanism: Compression strut between openings buckles like a column
   • Unique to: Closely spaced openings (s/h ratio critical)
   • Check: Slenderness ratio, critical stress
   • Formula: λ = (h/tw) × √(Fy/E) (web post slenderness)

3. Shear Strength (Section 3.4):

   • Mechanism: Tee section shear capacity at opening
   • Different from: Solid web shear (reduced area)
   • Check: Tee web shear capacity
   • Formula: Vn = 0.6 × Fy × Aw (tee web area)

4. Lateral-Torsional Buckling (Section 3.5):

   • Mechanism: Similar to solid beams but reduced Iy affects capacity
   • Modified for: Reduced web area (openings)
   • Check: Modified LTB equations with reduced Iy
   • Formula: Standard AISC Chapter F with adjusted properties

5. Deflection (Section 3.6):

   • Mechanism: Vierendeel deformation adds to beam deflection
   • Critical for: Low E/I ratio, service loads
   • Check: Use effective Ix (typically 90% of gross)
   • Formula: Δ = (5wL⁴)/(384 × E × Ieff) where Ieff ≈ 0.9 Ix

6. Local Web Yielding (Section 3.8):

   • Mechanism: High stresses at opening corners
   • Check: Opening reinforcement if needed
   • Common at: End reactions, concentrated loads

Keywords: failure mode, Vierendeel, web post buckling, 파괴모드, 비렌딜, 좌굴, mechanism

7. Application/Use Case Query (적용사례 질의)

User Intent: Understand where and when to use castellated/cellular beams.

Example Queries:

• "When should I use castellated beams?"
• "What are typical applications for cellular beams?"
• "Are honeycomb beams suitable for parking garages?"
• "허니컴보를 어디에 사용하나요?"
• "셀룰러보의 장단점은?"

Quick Process:

1. Search Chapter 2 (Use Cases) for applications
2. Reference Section 2.2 (Advantages) and 2.3 (Considerations)
3. Present typical applications with design considerations
4. Note when NOT to use (limitations)
5. Cross-reference to examples for similar cases

Typical Applications (from Chapter 2.1):

1. Parking Garages:

   • Long spans (40-60 ft typical)
   • MEP integration critical
   • Usually noncomposite
   • Example: Example 4.1 or 4.2

2. Residential Buildings:

   • Floor beams with utilities
   • Depth constraints (ceiling height)
   • Often composite with concrete slab
   • Example: Example 4.3 or 4.4

3. Commercial Buildings:

   • Office floors, retail
   • HVAC duct routing through openings
   • Architectural exposure possible
   • Composite or noncomposite

4. Industrial Facilities:

   • Equipment platforms
   • Utilities pass through openings
   • Moderate spans

Advantages (from Chapter 2.2):

• ✅ Increased depth without added weight (20-50% depth increase)
• ✅ MEP integration - utilities pass through openings
• ✅ Material efficiency - reuse parent section material
• ✅ Reduced floor height - services within beam depth
• ✅ Architectural appeal - exposed structure aesthetic

Special Considerations (from Chapter 2.3):

• ⚠️ Deflection reduction - Effective Ix only ~90% of gross Ix
• ⚠️ Complex analysis - Multiple failure modes (Vierendeel, web post)
• ⚠️ Fabrication cost - Cutting and welding labor intensive
• ⚠️ Not suitable for:
  • Heavy concentrated loads (unless reinforced)
  • Short spans (not economical)
  • High shear regions near supports
  • Dynamic/seismic critical applications (without special detailing)

Keywords: application, use case, when to use, 적용, 사용처, suitable, typical

Quick Reference Tables

Document Categories

Common Search Patterns

Chapter-to-Example Mapping

Legend: NC = Noncomposite, C = Composite, CB = Castellated Beam, LB = Cellular Beam (Long-span)

Units Convention

Performance Optimization

Search Strategy Priority

1. Beam type identification first: Always determine CB vs LB before searching

   • Quick check: references/geometry-guide.md for terminology
   • Hexagonal openings → Castellated Beam (CB)
   • Circular openings → Cellular Beam (LB)

2. Reference files before full search:

   • Symbols → references/symbols.md
   • Terms → references/glossary.md
   • Examples → references/examples-index.md
   • Geometry → references/geometry-guide.md
   • Failure modes → references/failure-modes-guide.md
   • Workflow → references/design-workflow-summary.md

3. Efficient chapter targeting:

   • Use topic keywords to identify specific chapter/section
   • Don't search all files - target 1-2 relevant sections
   • Example: "Vierendeel bending" → Only search Chapter 3.2 + examples

4. Smart document reading:

   • Read only relevant sections
   • Use offset and limit parameters for large files
   • Cross-reference between chapters and examples when needed

Python Script Usage

Execute automation scripts when appropriate (when implemented):

# Geometry calculation
python3 scripts/geometry_calculator.py --beam-type "CB" --parent-section "W16x26" --expansion-ratio 1.5

# Vierendeel moment calculation
python3 scripts/vierendeel_calculator.py --shear 25 --eT 12 --spacing 18

# Web post buckling check
python3 scripts/web_post_checker.py --spacing 18 --height 24 --thickness 0.25

# Category-aware search
python3 scripts/smart_search.py "web post buckling"

# Extract formula with context
python3 scripts/formula_finder.py "MV =" "Chapter_3"

# Find matching example
python3 scripts/example_matcher.py "composite cellular beam"

Response Quality Checklist

Every response should include:

• ✅ Accurate AISC DG31 citation (AISC Design Guide 31, Section X.Y or Example 4.Z)
• ✅ Beam type specified (CB = Castellated or LB = Cellular)
• ✅ Composite action clarified (composite or noncomposite)
• ✅ Opening geometry noted (hexagonal or circular, size, spacing)
• ✅ Opening size and spacing specified (critical for web post buckling)
• ✅ Units specified (ksi, in, ft, kip)
• ✅ Variable definitions from symbols.md
• ✅ Working Python code for calculations (tested and validated)
• ✅ Cross-references to examples when explaining formulas
• ✅ All failure modes checked (Vierendeel, web post, shear, LTB, deflection)
• ✅ Deflection reduction noted (Ieff ≈ 0.9 Ix for service loads)
• ✅ Limit states noted (yielding, buckling, rupture, serviceability)

Special Features: Unique Considerations

Critical Differences from Solid Web Beam Design

1. Vierendeel Mechanism (Unique to Web Openings)

Solid Beam: Shear carried continuously through web CB/LB: Shear transferred as local moments at opening corners (Vierendeel mechanism)

→ Must check tee section stresses combining flexure + Vierendeel moment

Formula: MV = V × eT (Vierendeel moment from shear force)

2. Web Post Buckling (Critical Spacing Check)

Solid Beam: Web buckling over full depth CB/LB: Web post acts as strut between openings - can buckle if spacing too small

→ Spacing ratio s/h must exceed minimum (typically s/h > 1.0-1.5)

Critical Check: λ = (h/tw) × √(Fy/E) < λr (limiting slenderness)

3. Geometry-Dependent Design (CB vs LB)

CB (Castellated): Hexagonal openings, diamond-shaped web posts, higher stress concentration LB (Cellular): Circular openings, rectangular web posts, smoother stress flow

→ Different formulas and checks apply for each type

Key Difference: Opening shape affects Vierendeel moment distribution

4. Deflection Reduction (90% Ix Factor)

Solid Beam: Use gross Ix for deflection CB/LB: Effective Ix reduced to ~90% of gross due to Vierendeel deformation

→ Deflection often controls design (serviceability critical)

Formula: Ieff ≈ 0.9 × Ix (simplified method from DG31)

5. AISC Specification Integration

Approach: Design Guide 31 supplements (not replaces) AISC Specification Integration: Use DG31 for opening-specific checks + AISC 360 for general provisions

→ Both documents required for complete design

Hierarchy: AISC 360 (base requirements) + DG31 (opening-specific procedures)

6. LRFD & ASD Dual Methods

Available: Both LRFD and ASD methods provided (unlike ADM which is ASD only) Typical: LRFD more common in modern U.S. practice

→ Specify which method when presenting calculations

Resistance Factors (LRFD): φ = 0.90 (flexure), φ = 0.90 (compression), φ = 1.00 (shear) Safety Factors (ASD): Ω = 1.67 (flexure), Ω = 1.67 (compression), Ω = 1.50 (shear)

Beam Type Selection Guide

For Castellated Beams (CB):

• Traditional applications (since 1910s)
• Moderate depth increase (e = 1.3-1.5 typical)
• Hexagonal aesthetic preferred
• Simpler fabrication (no CNC required)

For Cellular Beams (LB):

• Long-span applications (40-80 ft)
• MEP integration critical (circular openings easier)
• Lower stress concentration (smooth edges)
• Modern CNC fabrication available

For Composite Action:

• Building floors with concrete slabs
• Deflection control critical
• Higher strength requirements
• Shear studs acceptable

For Noncomposite:

• Parking garages (exposed structure)
• Industrial platforms
• No concrete slab present
• Simpler detailing

When to Use Chapter 1 vs 2 vs 3 vs Examples

Use Chapter 1 (Introduction) when:

• User asks "what is a castellated/cellular beam?"
• User needs manufacturing process explanation
• User wants nomenclature and terminology
• User asks "how are they made?"

Use Chapter 2 (Use Cases) when:

• User asks "when should I use this beam type?"
• User needs advantages/disadvantages
• User wants typical applications
• User asks "is this suitable for my project?"

Use Chapter 3 (Design Procedures) when:

• User asks "what is the formula?"
• User needs design check procedures
• User wants to understand limit states
• User asks "how do I check Vierendeel bending?"

Use Examples (Chapter 4) when:

• User asks "how do I calculate this?"
• User needs step-by-step procedure
• User wants to see complete worked solution
• User asks "show me a calculation"

Use Reference Files when:

• User asks about symbols or notation
• User needs geometric relationships
• User wants failure mode overview
• User needs quick lookup data

Use All Together when:

• Comprehensive design questions
• Teaching/learning scenarios
• Formula explanation with practical context
• Validation of calculations

Error Handling

Common Scenarios

1. Beam type not specified:

   • Ask user: "Is this a castellated beam (hexagonal openings) or cellular beam (circular openings)?"
   • Offer context: CB = traditional, LB = long-span/modern

2. Composite action unclear:

   • Ask user: "Is there a concrete slab providing composite action?"
   • Explain impact: Composite has higher strength and lower deflection

3. Opening geometry missing:

   • Ask user for:
     • Opening size (diameter or height)
     • Opening spacing (center-to-center)
     • Expansion ratio (for CB)
   • Note: These are critical for web post buckling

4. No results found:

   • Suggest alternative keywords
   • Check all document types (Chapters 1-3, Examples, References)
   • Recommend broader search terms
   • Check if query is in scope for DG31

5. Ambiguous query:

   • Clarify with multiple interpretations
   • Ask user: "Did you mean [castellated] or [cellular]?"
   • Present options for beam type and composite action

6. Missing parameters for calculation:

   • List required values:
     • Parent section (W-shape)
     • Expansion ratio or opening diameter
     • Spacing between openings
     • Span length
     • Loads (dead, live)
   • Offer typical default values from examples

7. Out of scope:

   • Clearly state DG31 limitations (normal gravity loads, typical buildings)
   • Not covered: seismic detailing, fatigue, fire design
   • Suggest consulting structural engineer for complex cases

Validation Checks

For all calculations:

• ✅ Verify beam type specified (CB or LB)
• ✅ Verify composite action clarified
• ✅ Check opening geometry defined (size, spacing)
• ✅ Verify units consistency (ksi, in, ft, kip)
• ✅ Check spacing ratio (s/h > minimum for web post stability)
• ✅ Verify deflection includes reduction factor (Ieff ≈ 0.9 Ix)
• ✅ Check all failure modes addressed (Vierendeel, web post, shear, LTB, deflection)
• ✅ Warn if parameters outside typical ranges:
  • Expansion ratio e < 1.2 or e > 1.6 (unusual)
  • Spacing s < 1.0h (web post buckling risk)
  • Span > 80 ft (may need special consideration)
• ✅ Note all assumptions (bracing, load cases, boundary conditions)
• ✅ Cross-check with example from Chapter 4 when possible

Special Notes

LRFD & ASD Methods (Both Available)

Unlike some design guides that use only one method, AISC Design Guide 31 provides both LRFD and ASD:

LRFD (Load and Resistance Factor Design):

• Design strength = φ × Nominal strength
• Load combinations from ASCE/SEI 7 (1.2D + 1.6L, etc.)
• Resistance factors (φ):
  • φ = 0.90 for flexure
  • φ = 0.90 for compression
  • φ = 1.00 for shear
  • φ = 0.75 for bolts/welds

ASD (Allowable Strength Design):

• Allowable strength = Nominal strength / Ω
• Load combinations from ASCE/SEI 7 (D + L, D + L + W, etc.)
• Safety factors (Ω):
  • Ω = 1.67 for flexure
  • Ω = 1.67 for compression
  • Ω = 1.50 for shear
  • Ω = 2.00 for bolts/welds

Which to use: Specify based on user preference or project requirements. LRFD more common in modern U.S. practice.

Design Examples Format

• Examples show complete step-by-step calculations
• Example numbering: 4.1, 4.2, 4.3, 4.4 (Chapter 4 examples)
• All examples cite specific AISC Specification and DG31 sections
• Results presented to appropriate significant figures (typically 3 sig figs)
• All failure modes checked in each example (comprehensive approach)
• Both LRFD and ASD methods shown (or noted when only one is applicable)

Version Tracking

• Design Guide: AISC Design Guide 31 (2nd Edition, 2016)
• Related Specification: AISC 360-16 (Specification for Structural Steel Buildings)
• Published by: American Institute of Steel Construction (AISC)
• Always cite version in responses: "AISC Design Guide 31 (2016)"

Default Assumptions (if not specified by user)

Unless specified otherwise, assume:

• Method: LRFD (more common in modern practice)
• Steel: ASTM A992 (Fy = 50 ksi, Fu = 65 ksi) - typical for W-shapes
• Composite: Noncomposite (unless slab explicitly mentioned)
• Beam type: Ask user - CB vs LB must be specified
• Deflection limit: L/360 for live load (typical floor beam)
• E = 29,000 ksi (modulus of elasticity for steel)

Always ask user to confirm critical assumptions before calculations.

For comprehensive castellated and cellular beam design work, this skill integrates:

1. Historical context from Chapter 1 (Introduction)
2. Application guidance from Chapter 2 (Use Cases)
3. Design procedures from Chapter 3 (Design Procedures)
4. Worked applications from Chapter 4 (Illustrative Examples)
5. Geometric relationships from reference files
6. Failure mode knowledge from failure-modes-guide
7. Workflow structure from design-workflow-summary

Always prioritize accuracy, cite sources (AISC DG31), specify beam type (CB/LB), clarify composite action, check all failure modes (especially Vierendeel and web post buckling), apply deflection reduction (0.9 Ix), and follow AISC methodology (LRFD or ASD).