Calculadora de Luz de Viga I de Acero
Encuentre la luz máxima de una viga de acero I para una carga determinada. La calculadora verifica tanto la capacidad de flexión como el límite de deflexión frente a una base de datos real de secciones, e informa la menor de las dos luces — la que realmente gobierna.
Luz máxima
Fb = 0.66 Fy, E = 200 GPa, compacta y lateralmente arriostrada, peso propio no deducido. Solo dimensionamiento preliminar — haga verificar por un ingeniero calificado.
Cómo se deriva la luz máxima
- Por flexión: carga uniforme L = √(8M/w); carga puntual central L = 4M/P.
- Por deflexión con límite L/n: carga uniforme L = ∛(384EI / (5wn)); carga puntual central L = √(48EI / (Pn)).
Preguntas frecuentes
¿Qué distancia puede alcanzar una viga de acero I?
Depende de la sección, la carga y el límite de deflexión que acepte. Esta calculadora devuelve la luz máxima tanto de la verificación de flexión como de la verificación de deflexión, e informa la menor de las dos — ese es el límite real.
¿Qué suele limitar la luz, la resistencia o la deflexión?
La deflexión, en la mayoría de los entramados de pisos. Debido a que la deflexión crece con la cuarta potencia de la luz, el límite de deflexión se alcanza antes que el límite de flexión en todas las vigas excepto en las cortas y ligeramente cargadas.
¿Qué carga debo ingresar?
La carga de servicio total que soporta la viga por metro, incluyendo carga muerta (peso propio, losa, acabados) y carga viva. No aplique factores de carga del código — esta es una verificación de servicio por tensión admisible.
¿Puedo usar esto para un voladizo?
Seleccione el caso de carga de voladizo. Un voladizo de la misma longitud se deflecta aproximadamente 9.6 veces más que una viga simplemente apoyada bajo carga uniforme, por lo que las luces admisibles en voladizo son mucho más cortas.
Herramientas relacionadas: Capacidad de carga · Luz · Selector de viga · Deflexión · Peso del metal · Todas las 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.