Trailer Design Guideline > Manufacturing
Edge quality
Our experience has shown that the primary cause of fatigue failures in trailer chassis is poor weld quality.
Therefore, it is vital to not only thoroughly evaluate the new upgraded design, but to secure the production process. Poor weld or edge quality will rapidly decrease the service life of any trailer.
Edge quality also impacts fatigue resistance, and different cutting methods result in different edge qualities. The graph below shows the results of fatigue testing Strenx® 700MC where the plate edge has been milled, laser-cut and sheared. Laser-cut edges are often better than mechanically cut edges. To achieve good fatigue strength with mechanically cut edges, it is important to remove all visual crack-like defects. Modern thermal cutting processes like laser or high-definition plasma generally produce edges in Strenx® 700MC with good fatigue properties. The ranking of such methods from a fatigue perspective would be laser, plasma and gas-cutting. To avoid fatigue problems, it is also important to place start and stop positions in low-stress areas. Blasting of a structure with cut edges normally has a positive effect on fatigue resistance.
Results from fatigue testing Strenx® 700MC with different edge conditions.
The information in this report is only applicable to SSAB’s products and should not be applied to any other products than original SSAB products.
This report provides general results and recommendations for SSAB steel products. This report is subject to SSAB’s Terms of Use. It shall be the user's responsibility to verify that the information contained herein is correct and is suitable to be used for the particular purpose and application of the user. The report is intended to be used by professional users only who possess adequate expertise, qualification and knowledge for the safe and correct use of the results and recommendations in this report. This report is provided “as is”. The use of the report is at user’s own discretion and risk and that users will be solely responsible for any use of this report. SSAB disclaims any liability for the content or potential errors of this report, including but not limited to warranties and condition of merchantability or fitness for a particular purpose or suitability for individual applications. SSAB shall not be liable for any kind of direct or indirect damages and/or costs related to or arising therefrom, whether special, incidental, consequential or directly or indirectly related to the use of, or the inability to use, the report or the content, information or results included therein.