Participation of IK4-AZTERLAN in the technical session of Joint Technologies for advanced industrial applications
Mr. Urko Uribe and Mr. Garikoitz Artola have taken part in this relevant working frame to share the knowledge and expertise of the Metallurgy Research Centre in the field of advanced joint technologies.
Organized by IK4 Research Alliance, this interesting technical session has gathered the participation of 100 professionals from more than 50 different companies and organizations.
In the chairman role, Mr. Garikoitz Artola, coordinator of the Forming Technologies Area of IK4-AZTERLAN introduced the event to the audience underlining the importance of joint technologies “present in diverse industrial sectors such as biomedicine, civil engineering, energy or transport sectors, among others” and emphasized their high innovative compound and their interdisciplinary attribute.
Later on, Mr. Urko Uribe, coordinator of the Physical and Mechanical Properties Area of IK4-AZTERLAN put the focus of his presentation on high performance bolted joints, the mechanical reversible joints that assemble one or multiple pieces by means of fixing elements. This kind of joints are widely used by the wind energy sector, aeronautics and the automotive industry. IK4-AZTERLAN counts with important development capacities in this area of knowledge.
Mr. Uribe presented the main advantages and the key characteristics of bolted joints as “a convenient joining system for diverse applications thanks to their reversibility, simple design (screwed elements that join elements), low cost and high level of standardization”.
Mr. Urko Uribe (left) and Mr. Garikoitz Artola (right) in the conference on high performance bolted joints celebrated on the 8th of November.
Mr. Uribe emphasized that the preload (joint force) is one of the main parameters to be considered when designing this kind of joints because “it offsets external charges and ensures the correct performance of the joint”. Also he added that high preloads, close to the elastic limit of the material, protect screws from the fatigue phenomena they are exposed to during the service life of the component.
The coordinator of the mechanical testing area from IK4-AZTERLAN also informed about the different tightening methods and their main characteristics assuring that “the tightening method, along with the human factor (expertise of the workers on the tightening operations), equipment used and the fixing elements applied are the four crucial factors for obtaining a secure screwed joint”. Deepening into the tightening methods:
- Tightening torque method: is the most extended one and the easiest and quickest to perform. Preload is obtained thanks to the direct application of the torque effort on the screw or on the bolt head.
- Tightening torque + angle method: is the most precise one. It minimizes the dependence from environmental conditions. The preload is obtained by applying directly the torque, plus a rotation angle in the final tightening phase.
- Hydraulic tightening method: This is also a high precision method. At the same time many joints can be tightened. This method applies no torsion tension on the screw. .
Mr. Urko Uribe concluded his presentation sharing with the audience some of the main testing methods applied to bolted joints, both bench verification methods and testing methods to determine the dynamic behavior of the joints.
A more detailed information can be obtained on the different characterization methods here.