Trailer Fabrication: The Importance of Weld Joint Efficiency

Blog | April 23rd, 2020

Most trailer fabrication works require multiple seam welds for them to be effective. Manufacturers would find the right settings just to achieve high productivity of trailer fabrication. With welding, one crucial factor in trailer fabrication is the weld joint efficiency.

What is weld joint efficiency?

Weld joint efficiency is defined as the reliability obtained from the joints after welding. This specific element helps reduce the allowable stress of the welded material. This coefficient adopts values smaller than 1 and typically depends on the level of Non-Destructive Examination (NDE), category, and the type of the weld joints.

How is weld joint efficiency done and determined?

The efficiency of the weld joints relies on different weld configurations, the ability to transfer the loads that will be withstood by the pressure level in varying degrees, and uncertainties in the quantity of the joints. Any defects will be determined once a weld joint is fully inspected as long as the NDE is conducted properly. Alternatively, partial inspections will result in a joint efficiency of less than one, which will decrease the allowable stress of the welded material.

The welds condition of a trailer fabrication is deemed great if the NDE level is high and the joint preparation of pieces to be welded is done optimally. So, when designing a trailer, you must strictly consider the joint efficiency of its parts.

Why is weld joint efficiency important?

Weld joint efficiency in trailer fabrication is important since it accounts for how closely a finished weld joint tells the quality of the seamless base material. Inspections and tests must also be done to avoid any potential defects such as porosity, slag inclusions, and others on the final trailer product.

Designers of some products are required to specify full radiography. In some cases, however, they can specify an optional radiographic examination that is intended to increase joint efficiency and reduce the required thickness of shells and heads. Designers will also have to weigh the material and welding costs against inspection costs so that they can determine the best welding application possible.

How to achieve great weld joint efficiency in trailers?

To ensure great weld joint efficiency for your trailer fabrication, you must make sure that your heat input is correct. Since trailers utilise high strength grades of steel, your maximum heat input must be calculated accurately to prevent any inconsistencies. The calculation for heat input is as follows: Heat Input (Q) = E × k, where E = (U × I × 60) / (v × 1000) kj/mm. The ‘k’ is for arc efficiency, ‘U’ for voltage, ‘I’ for current, and ‘v’ is for travel speed (mm/min).

You must also use a proper filler metal for greater results. Professionals can use aluminium filler metal 5356 since it can be easily obtained. This metal can also be used with 5xxx and 6xxx base aluminium that is normally found in trailer frame construction.

Aside from heat input and choice of proper filler metal, you must also maintain appropriate weld amplitude, especially for inline weaving or shuffling. The practice of inline weaving will not have any impact on your trailer when performed correctly. The width of the weaving must be between 3-4 mm in amplitude to maintain great weld joint efficiency.

Weld joint efficiency is important to make your trailer fabrication a success. For more information about this element, you can talk to us at McKean’s Sheetmetal Fabricators. We are your first choice for metal fabrication and solutions.

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