Kalkulator Bentang Balok I Baja
Temukan bentang maksimum balok-I baja untuk beban tertentu. Kalkulator memeriksa kapasitas lentur dan batas lendutan terhadap database penampang nyata, dan melaporkan bentang yang lebih pendek dari keduanya — yang sebenarnya menentukan.
Bentang maksimum
Fb = 0,66 Fy, E = 200 GPa, kompak dan ditopang lateral, berat sendiri tidak diperhitungkan. Hanya pra-rencana — mintalah insinyur berkualifikasi untuk memverifikasi.
Cara bentang maksimum ditentukan
- Dari lentur: beban merata L = √(8M/w); beban titik tengah L = 4M/P.
- Dari lendutan dengan batas L/n: beban merata L = ∛(384EI / (5wn)); beban titik tengah L = √(48EI / (Pn)).
Pertanyaan yang sering diajukan
Seberapa jauh bentang balok-I baja?
Tergantung pada penampang, beban, dan batas lendutan yang Anda terima. Kalkulator ini mengembalikan bentang maksimum dari pemeriksaan lentur dan pemeriksaan lendutan, dan melaporkan yang lebih kecil dari keduanya — itulah batas sebenarnya.
Manakah yang biasanya membatasi bentang, kekuatan atau lendutan?
Lendutan, pada sebagian besar rangka lantai. Karena lendutan bertambah dengan pangkat empat bentang, batas lendutan tercapai sebelum batas lentur pada semua balok kecuali yang pendek dan berbeban ringan.
Beban apa yang harus saya masukkan?
Total beban layanan yang dipikul balok per meter, termasuk beban mati (berat sendiri, pelat, finishing) dan beban hidup. Jangan terapkan faktor beban peraturan — ini adalah pemeriksaan kelayanan tegangan izin.
Dapatkah saya menggunakan ini untuk kantilever?
Pilih kasus beban kantilever. Kantilever dengan panjang yang sama melendut kira-kira 9,6 kali lebih besar daripada balok tumpuan sederhana di bawah beban merata, sehingga bentang izin kantilever jauh lebih pendek.
Alat terkait: Kapasitas Beban · Bentang · Pemilih Balok · Lendutan · Berat Logam · Semua kalkulator
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.