Calculadora de Vão de Viga I de Aço
Encontre o vão máximo de uma viga I de aço para uma carga determinada. A calculadora verifica tanto a capacidade de flexão quanto o limite de deflexão em um banco de dados real de seções e informa o menor dos dois vãos — aquele que realmente governa.
Vão máximo
Fb = 0,66 Fy, E = 200 GPa, compacta e lateralmente apoiada, peso próprio não deduzido. Dimensionamento preliminar apenas — consulte um engenheiro qualificado para verificação.
Como o vão máximo é obtido
- Da flexão: carga uniforme L = √(8M/w); carga pontual central L = 4M/P.
- Da deflexão com limite L/n: carga uniforme L = ∛(384EI / (5wn)); carga pontual central L = √(48EI / (Pn)).
Perguntas frequentes
Qual é o vão máximo de uma viga I de aço?
Depende da seção, da carga e do limite de deflexão que você aceita. Esta calculadora retorna o vão máximo a partir da verificação de flexão e da verificação de deflexão, e informa o menor dos dois — esse é o limite real.
O que geralmente limita o vão, resistência ou deflexão?
Deflexão, na maioria dos pisos. Como a deflexão cresce com a quarta potência do vão, o limite de deflexão é atingido antes do limite de flexão em todas as vigas, exceto nas curtas e com carga leve.
Qual carga devo inserir?
A carga total de serviço que a viga suporta por metro, incluindo carga permanente (peso próprio, laje, acabamentos) e carga variável. Não aplique fatores de carga normativos — esta é uma verificação de serviço por tensão admissível.
Posso usar isso para um balanço?
Selecione o caso de carga de balanço. Um balanço do mesmo comprimento deflete aproximadamente 9,6 vezes mais que uma viga simplesmente apoiada sob carga uniforme, portanto os vãos admissíveis em balanço são muito menores.
Ferramentas relacionadas: Capacidade de Carga · Vão · Selecionador de Viga · Deflexão · Peso do Metal · Todas as calculadoras
Steel I-Beam Span Calculator
Calculate the maximum allowable span, deflection, and load capacity for steel I-beams based on structural engineering principles.
Analysis Results
Beam Loading Diagram
How to Use This I-Beam Span Calculator
Understanding Steel I-Beam Span Calculation
Steel I-beams are structural elements designed to support loads across an open space. Determining the appropriate beam size requires an understanding of the relationship between:
- Span Length: The distance between supports that the beam must bridge
- Applied Load: The weight or force that the beam must support (uniform, point, or combination)
- Steel Properties: The strength and stiffness characteristics of the steel
- Deflection Limits: The maximum allowable bending of the beam under load
- Safety Factors: Additional capacity to account for unpredictable conditions
Using the Calculator for Span Analysis
- Select the I-beam type (Wide Flange, American Standard, or Bearing Pile)
- Choose a standard size from the dropdown menu
- Select the load type (uniform, point load at center, point loads at third points, or cantilever)
- Enter the total load that the beam must support
- Specify the beam span (distance between supports)
- Select the steel grade based on the material specification
- Choose a deflection limit appropriate for your application
- Set a safety factor (typically 2.0-3.0 for standard applications)
- Click "Calculate" to analyze the beam performance
Using the Beam Selection Tool
If you know your required moment, span, and load but need help selecting an appropriate beam:
- Switch to the "Select Beam" tab
- Enter your required moment capacity (or let the calculator determine this from span and load)
- Specify the required span and design load
- Select the steel grade and deflection limit
- Click "Find Suitable Beam" to receive recommendations
Interpreting the Results
The calculator provides comprehensive results, including:
- Maximum Moment: The highest bending force in the beam
- Maximum Deflection: How much the beam will bend under the specified load
- Utilization Ratio: How much of the beam's capacity is being used (should be less than 100%)
- Maximum Allowable Span: The longest span this beam can safely bridge given the load
- Maximum Load Capacity: The greatest load this beam can support over the specified span
A high utilization ratio (>80%) suggests that you should consider a larger beam for additional safety margin.
Design Considerations
When selecting an I-beam, consider these factors beyond the calculator results:
- Lateral Bracing: Unbraced beams may require larger sections to prevent lateral buckling
- Connection Details: How the beam will be fastened to supporting structures
- Dynamic Loads: Moving or vibrating loads may require additional capacity
- Environmental Factors: Exposure to corrosive environments may affect beam performance
- Local Building Codes: Always verify that your design meets all applicable building codes
Important: This calculator is a tool to assist in preliminary design. Final designs should be reviewed and approved by a licensed structural engineer.
Standard I-Beam Properties
| Designation | Depth (in) | Weight (lb/ft) | Area (in²) | Ix (in⁴) | Sx (in³) |
|---|
Common Loads for Structural Design
| Application | Typical Load (lb/ft²) | Description |
|---|---|---|
| Residential Floors | 40-50 | Living areas in houses, apartments |
| Office Floors | 50-80 | Standard office spaces |
| Retail Spaces | 75-100 | Shops, stores, light retail |
| Assembly Areas | 100-150 | Auditoriums, churches, theaters |
| Storage Areas | 125-250 | Warehouses, libraries, file rooms |
| Industrial Spaces | 150-400 | Manufacturing, workshops |
| Roof (Snow Load) | 20-40 | Varies by climate zone |
Notes on Loads:
- Live loads are temporary or movable loads such as people, furniture, and equipment.
- Dead loads are permanent loads such as the weight of the structure itself, flooring, and fixed equipment.
- Total design load should include both live and dead loads multiplied by appropriate load factors.
- Local building codes may specify different minimum design loads based on climate and locality.
- For critical applications, consult with a structural engineer to determine appropriate design loads.