Versatile Joining Technologies

2023 Author : Hannah Pearcy | [email protected] . Last modified: 2023-05-24 11:12

Joints permanently shape the properties of products. While a washing machine can be held together with just a few clinching points - simply by shaping and without auxiliary joining parts such as screws - a car body with up to 3500 punch rivet connections has to be joined. But the variety of products is increasing and the desire for light but stable structures places high demands on the joining technology. Versatile process chains and flexible joining processes are in demand

This is where scientists from the Collaborative Research Center "Method Development for Mechanical Feasibility in Versatile Process Chains" at the University of Paderborn start: Their goal is to improve production conditions by developing versatile joining technologies that break up previous rigid processes and enable a flexible process chain. "The availability of components is often the key to efficient production processes and is increasingly becoming a strategic competitive factor for the development and production location in Germany when it comes to series production of a wide variety of products," explains Prof. Dr.-Ing. Gerson Meschut, spokesman for the collaborative research center and head of the Laboratory for Materials and Joining Technology (LWF) at the University of Paderborn.

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Limited design options

So far, however , mechanical joining processes have been rigidly configured for the corresponding product. "This not only limits the design freedom in the choice of materials, but also the design options of brands," explains Meschut. If there are changes in production - for example, the change in the sheet thickness of a car body - all adjustments to the processes must currently be tried out using trial-and-error methods . "This can cause very high costs and must be changed with regard to the use of resources and environmental pollution," emphasizes the scientist.

Conversion and forecasting ability of mechanical joining processes

In the Collaborative Research Center, the scientists scrutinize the entire process chain - from the material (suitability for joining) to construction (joining reliability) to manufacture (joining option). Since 2019, they have been researching how targeted changes in product development can be made possible in versatile process chains. As a result, it is intended to be possible to carry out precise revisions in the individual process steps, for example on the semi-finished product, the joint, the component or the joining process. The result is a unique joint with its own mechanical property profile with regard to different types of stress.

Book tip

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Holistic forecasting along the process chain

So far, one has experimented with changes in the production process. But the number of material-geometry combinations is growing and the methodology is therefore not efficient. Because: "The holistic prognosis along the entire process chain is crucial for the properties of the final product," says Meschut.

The scientists work with computer simulations and experimental test methods . The entire properties of the various connections are considered: from the individual joining part materials (joining suitability), e.g. As aluminum, steel or plastic, via the matching joining processes (joining option) to the ultimate resilience (joining reliability), e.g. B. suddenly as in the vehicle crash or swinging as when driving.

Universal solutions

The long-term goal of the scientists is to create a flexible, transferable and cross-industry design method that accurately predicts the properties and requirements of new joining tasks. This should not only enable more reliable predictions of the availability and improve connection properties, but also achieve economic advantages.

Interdisciplinary team of researchers

"Around 60 scientists from the fields of materials technology, construction, mechanics, measurement technology and lightweight construction cooperate here in order to penetrate the subject of connectivity from all sides," says Meschut. The Paderborn scientists work together with scientists from the Technical University of Dresden and the Friedrich Alexander University of Erlangen-Nuremberg in an interdisciplinary research network, divided into 16 sub-projects. The German Research Foundation (DFG) is funding the Transregio Initiative TRR 285 to 2023 with around 10 million euros.