To assist the detailer in selecting the appropriate connection type, the following guide has been prepared to provide an insight into the practical advantages and disadvantages of each, which includes:

Though all these connection types work and generally fulfill the criteria of being 'Flexible' they each carry properties which may or may not suit the particular application. As will be seen, the connection that uses the less material, or uses less bolts, is not necessarily the most economical in terms of fabrication and erection.

The key to economic fabrication lies in the ability to standardize, and the degree to which it can be standardized will have an impact on its suitability.

Welded End-Plates

Advantages Disadvantages
1. Versatile and flexibly efficient, ideal for most beam-to-Beam connections

2. Cost effective in terms of material usage if standard ‘Flats’ are used

3. Easy to handle in the workshop

4. A very high level of standardization can be achieved

5. No drilling or punching of beam ends required

6. An opportunity to pre-fabricate ‘standard’ end-plates as a separate fabrication function.

7. May be adapted to suit a great variety of bolt-hole gauges, particularly narrow gauges

 

1. If not cut from standard ‘Flats’ the plates must be marked-out and cut from plates which, if not properly ‘nested’ may result in excessive off-cut waste

2. End-plates must be shop-welded to the beam-ends which may require addition workshop handling

3. Care must be taken to avoid damage to the end-plates during handling and transportation

4. Can be difficult to erect particularly with Beam-to-Beam connections with wide flange sections, or when connecting to the web of a column.

5. Beam length must be cut to a high degree of accuracy as site adjustment is limited.

6. ‘Shared-Bolts’ must be considered when connecting to a beam or column web

7. With Beam-to-Beam connections the top flange will most likely need to be Notched

Bolted End-Cleats

Advantages Disadvantages
1. Very versatile can be used for almost any application from the heaviest to lightest connection.

2. Ease of fabrication if using standard rolled angle sections

3. Easy to handle in the workshop

4. Minimum ‘turning’ of the work in the workshop, ideal for workshops with limited handling facilities

5. An opportunity to pre-fabricate end-cleats as a separate fabrication function, thereby allowing the fitting of the cleats to the beam ends to become a straightforward assembly exercise

6. Cleats may be loosened or removed completely on site to facilitate erection, particularly when clearances are tight.

7. Additional tolerance on beam length allowed to the workshop due to its site adjustability

7. No Welding

8. Ideal for connections which may be subject to fatigue.

1. Not the most economical in terms of material usage

2. Shop-bolts must be provided

3. Sometimes there can be a problem with ‘shared bolts’ where adjacent beams connect to a common supporting beam

4. Not really suitable for connecting to columns with a flange width, or web (tw) less that 200-mm.

5. They lend themselves only to a limited degree of standardization depending upon the method used for ‘setting-out’

See Standardizing Flexible Connections

6. Limited options for bolt-hole gauges

7. With Beam-to-Beam connections the top flange will most likely need to be Notched

 

Welded Fin-Plates

Advantages Disadvantages
1. Versatile and flexibly efficient, ideal for smaller beam connections

2. Cost effective in terms of material usage if standard ‘Flats’ are used

3. A very high level of standardization can be achieved

See Standardizing Flexible Connections

4. An opportunity to pre-fabricate ‘standard’ Fin-Plates as a separate fabrication function

5. Easy and straightforward to erect on site

6. No problems with ‘shared bolts’

1. Generally suitable for lighter connections and not considered fully ‘flexible’ in the vertical plane, as a result there are limitations for its use.

2. larger welds required

3. If not cut from standard ‘Flats’ the plates must be marked-out and cut from plates which, if not properly ‘nested’ may result in excessive off-cut waste

4. Fin-plates are welded to the web of the supporting beam, which, if they are on both sides of the beam, will require turning in the workshop. Efficient handling facilities must be available

5. With Beam-to-Beam connections the top flange will most likely need to be Notched.

6. When connecting to a column web, the bottom flange will most likely need to be stripped on one side for erection.

7. Fin-Plates do not readily lend themselves to Bracing and Gusset-Plate connections

Welded Tee Connections

Advantages Disadvantages
1. Standard end-plate of cleat fitted to the end of the connecting beam

2. Not necessary to notch the end of the connecting beam

3. Easier to erect on site, especially on deep section beams or girders

4. No problems with ‘shared’ bolts

5. Works well when adjacent beams are of greatly differing sizes

1. Least cost effective in terms of material usage

2. A lot of shop welding required

3. Beam may have to be frequently turned if Tees are fitted to both sides of the beam

 

Seating Connections

Advantages Disadvantages
1. Due to the additional clearances, a greater tolerance on fabrication length

2. Relative ease of erection

3. The seating-cleat may be either welded or bolted to the column

4. No problems with ‘shared-bolts’

1. Top flange of beam must be restrained, effectively doubling the connection

2. Packer-Plates need to be provided meaning site adjustment must be carried out to ensure levels.

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