Designing a monorail beam as per IS 800:2007 (General Construction in Steel – Code of Practice) involves several steps to ensure that the structure is capable of supporting the loads applied during its operation. Monorails are commonly used in material handling systems and typically consist of a steel beam supporting a trolley or hoist for load movement.

1. Input and Requirements 

Given Parameters:

1. Load Details:
   • Dead load (Wd​) – Self-weight of the monorail and attachments.
   • Live load (Wl​) – Load from the hoist and trolley system, including lifted material.
   • Impact factor (Ci​) – Typically 25–50% of the live load for dynamic effects.
2. Span of the Monorail Beam (L).
3. Material Properties:

• Grade of steel: Fe 250, Fe 345, or Fe 415.
• Allowable stresses and modulus of elasticity (E=2×105 MPa).

2. Load Combinations

• Design the beam to resist the factored loads as per IS 800:2007:

Wu ​= 1.5 (Wd ​+ Wl​ × (1+Ci​))

Where:

• Wu​ = Total factored load.

3. Bending Moment and Shear Force

Maximum Bending Moment (Mu​):

For a simply supported beam:

Mu​ = Wu​L ​/ 4

Maximum Shear Force (Vu​):

Vu=Wu/2​​

4. Selection of Section

Choose a suitable I-section or H-section beam based on bending strength, shear strength, and deflection criteria.

Bending Strength:

The design bending strength (Md​) is given by:

Md = βb ⋅ Zp ⋅ fy / γm

Where:

• βb​: Bending strength modification factor (as per IS 800:2007 Table 8).
• Zp​: Plastic section modulus (from steel tables).
• fy​: Yield stress of steel.
• γm=1.1: Partial safety factor.

Ensure:

Md ≥ Mu

Shear Strength:

The design shear strength (Vd​) is:

Vd = fy⋅Aw / sqrt(3) ⋅ γm

Where:

• Aw​: Web area of the section.

Ensure:

Vd ≥ Vu

Deflection Check:

The vertical deflection should not exceed:

Δmax=L / 325

The actual deflection is calculated as:

Δ = 5 ⋅ W ⋅ L³ / 384 ⋅ E ⋅ I

Where:

• I: Moment of inertia of the selected section.

5. Monorail Bottom Flange Check

The trolley wheels apply concentrated loads on the bottom flange of the monorail. Perform a local bending check on the flange using:

σ=P / bf⋅tf

Where:

• P: Load on the flange.
• bf​: Width of the flange.
• tf​: Thickness of the flange.

Ensure:

σ ≤ fy

6. Lateral-Torsional Buckling Check

For long-span beams, lateral-torsional buckling (LTB) may govern the design. Use the LTB check as per IS 800:2007 Clause 8.2.2:

Mcr=π² ⋅ E ⋅Iz / Lb²⋅ (sqrt(1+ (G⋅ J / π² ⋅ E ⋅ Iz))

Where:

• Lb​: Effective length for buckling.
• Iz: Moment of inertia about the weak axis.
• J: Torsional constant.
• G=E / 2(1+ν) ​: Shear modulus.

Ensure:

Mcr≥Mu

7. Connection Design

Beam-to-Support Connection:

Design the bolted or welded connection to resist:

• Maximum reaction (R=Wu/2) at the supports.

End Plate or Bracket Design:

For end brackets or support plates, ensure adequate thickness and bolt capacity to prevent failure.

Search

Search

• 3D HOUSE DESIGN (9)
• Civil and Structural Design Calculations (31)
• Commercial Plans (5)
• Engineering Concepts – Civil & Structural (88)
• Excel Spreadsheets (16)
• House Plans (38)
• Industrial standards (28)