On the backward design—an advanced concept for the design of welded structures for demanding applications

Conventionally, the design of welded structures is based on the properties of semi-finished products, such as rolled plates and strips. The effects of manufacturing processes on the material properties, such as cold forming and welding, are neglected or they are controlled by the limitations on manufacturing parameters. However, such conventional approaches do not obtain desired solutions for the end users in terms of performance of the end product. This is the case, particularly when using high-strength steels, in which the manufacturing processes can remarkably change the properties of semi-finished products, and the production quality must fulfill higher criteria compared to the structures made of low-strength or mild steels. Consequently, a new approach called backward design (BD) is established to obtain better properties for end-products and to develop more purposeful steels, improve quality in design and manufacturing, and minimize the lead time in the whole production chain. The BD concept is based on the needs of end-users and exploits simulations and digital twins, considering the whole production. However, the optimization of production, including all its adjacent phases, is a comprehensive multi-parametric task, and, thus, it will be always a compromised solution. Nevertheless, the BD concept provides a new way of thinking about the whole production, not only material but also the geometry of the construction and its fabrication phases. The issue is currently relevant because the steel industry will transform toward “green” steels (hydrogen-based reduction) and thus enable the creation of new tailored steels for end-products. In this paper, a general overview of this concept is presented.