Types of Beams

I. Introduction

In structural design and drawing, it is crucial to understand the different types of beams and their role in supporting loads in a structure. Beams are horizontal structural members that transfer loads from the superstructure to the substructure. They play a vital role in maintaining the structural integrity and stability of a building or any other structure.

II. Beams with Compression Reinforcement

Compression reinforcement is used in beams to enhance their load-carrying capacity and prevent failure due to excessive compression forces. There are two main types of beams with compression reinforcement: doubly reinforced rectangular beams and flanged beams.

A. Doubly Reinforced Rectangular Beams

Doubly reinforced rectangular beams are reinforced concrete beams that have both tension and compression reinforcement. The purpose of compression reinforcement is to resist the compressive forces that develop in the beam.

1. Design Considerations

When designing a doubly reinforced rectangular beam, several factors need to be considered, including the load requirements, material properties, and design codes and standards. The design process involves determining the required dimensions of the beam, selecting the appropriate reinforcement, and ensuring that the beam meets the strength and deflection criteria.

2. Step-by-step Design Process

The design of a doubly reinforced rectangular beam involves the following steps:

1. Determine the design loads and load combinations.
2. Calculate the required dimensions of the beam based on the applied loads and material properties.
3. Select the appropriate reinforcement based on the design requirements.
4. Check the beam for strength and deflection criteria.

B. Flanged Beams

Flanged beams are another type of beam that utilizes compression reinforcement. These beams have a flange, which is a horizontal plate or section that extends beyond the web of the beam. The flange increases the load-carrying capacity of the beam and provides additional stiffness.

1. Design Considerations

The design of flanged beams involves considering factors such as the load requirements, material properties, and design codes and standards. The design process includes determining the required dimensions of the beam, selecting the appropriate reinforcement, and ensuring that the beam meets the strength and deflection criteria.

2. Real-world Applications

Flanged beams are commonly used in various structures, including bridges, multi-story buildings, and industrial facilities. They are particularly suitable for situations where high load-carrying capacity and stiffness are required.

III. Redistribution of Moments in Continuous Beams

Continuous beams are beams that are supported by more than two supports. They are used in structures where long spans or continuous load paths are required. Redistribution of moments in continuous beams refers to the redistribution of bending moments that occurs when a load is applied to the beam.

A. Definition and Explanation

Continuous beams are designed to redistribute moments to achieve a more efficient load distribution. This redistribution of moments helps to reduce the bending moments and shear forces in certain sections of the beam, resulting in a more balanced load distribution.

B. Significance in Structural Design

The redistribution of moments in continuous beams has significant implications for structural design. It allows for a more economical design by reducing the overall size and amount of reinforcement required. It also helps to improve the structural performance and load-carrying capacity of the beam.

C. Step-by-step Redistribution Process

The redistribution of moments in a continuous beam involves the following steps:

1. Determine the initial moments and shear forces in the beam.
2. Analyze the beam for the applied loads and support conditions.
3. Calculate the redistributed moments and shear forces based on the analysis results.
4. Check the beam for strength and deflection criteria.

IV. Circular Girders

Circular girders are structural members that have a circular cross-section. They are commonly used in the construction of bridges, tunnels, and other structures that require curved or circular shapes.

A. Definition and Purpose

Circular girders are designed to provide support and stability to structures that require curved or circular shapes. They offer several advantages, including increased load-carrying capacity, improved structural performance, and enhanced aesthetic appeal.

B. Design Considerations

When designing circular girders, several factors need to be considered, including the radius of curvature, the applied loads, and the material properties. The design process involves determining the required dimensions of the girder, selecting the appropriate reinforcement, and ensuring that the girder meets the strength and deflection criteria.

C. Real-world Examples

Circular girders are commonly used in the construction of bridges, such as arch bridges and cable-stayed bridges. They are also used in the construction of tunnels, where the circular shape helps to distribute the loads evenly and provide structural stability.

V. Deep Beams

Deep beams are beams that have a large depth-to-span ratio. They are used in structures where high shear forces and bending moments are expected, such as transfer girders, corbels, and foundation beams.

A. Definition and Characteristics

Deep beams are characterized by their large depth-to-span ratio, which helps to distribute the loads more efficiently and reduce the shear forces and bending moments. They are designed to resist the high shear forces and bending moments that develop in these types of structures.

B. Design Considerations

When designing deep beams, several factors need to be considered, including the applied loads, material properties, and design codes and standards. The design process involves determining the required dimensions of the beam, selecting the appropriate reinforcement, and ensuring that the beam meets the strength and deflection criteria.

C. Advantages and Disadvantages

Deep beams offer several advantages, including increased load-carrying capacity, improved structural performance, and reduced deflection. However, they also have some disadvantages, such as increased construction costs and more complex construction techniques.

VI. Conclusion

In conclusion, understanding the different types of beams is essential in structural design and drawing. Beams with compression reinforcement, such as doubly reinforced rectangular beams and flanged beams, enhance the load-carrying capacity of the structure. Redistribution of moments in continuous beams improves the structural performance and load distribution. Circular girders provide support and stability to structures with curved or circular shapes. Deep beams are designed to resist high shear forces and bending moments. By considering the specific requirements of a structure, engineers can select the appropriate type of beam to ensure the structural integrity and stability of the building or structure.

Summary

In structural design and drawing, it is crucial to understand the different types of beams and their role in supporting loads in a structure. Beams with compression reinforcement, such as doubly reinforced rectangular beams and flanged beams, enhance the load-carrying capacity of the structure. Redistribution of moments in continuous beams improves the structural performance and load distribution. Circular girders provide support and stability to structures with curved or circular shapes. Deep beams are designed to resist high shear forces and bending moments. By considering the specific requirements of a structure, engineers can select the appropriate type of beam to ensure the structural integrity and stability of the building or structure.

Analogy

Imagine a bridge as a structure made up of different types of beams. The main beams that support the weight of the bridge are like the backbone of the structure, ensuring its stability and strength. Just as different parts of the human body have different functions, different types of beams have specific roles in supporting loads and maintaining the structural integrity of the bridge. Understanding the different types of beams is like understanding the different parts of the body and how they work together to keep the bridge standing.