A recent survey by the Federal Highway Research Institute (BAM) showed that nearly 5,000 long-distance bridges in Germany were rated as "inadequate" or worse, with over 700 of them even rated as "unsatisfactory". Whereas bridges were previously inspected during annual inspections, BAM considers it necessary to significantly change the inspection measures in view of this disastrous result. Its plan, which BAM will also present at HANNOVER MESSE 2022, is to continuously monitor bridges in the future using digital twins in order to identify weak points at an early stage. In addition, unexpected damage is to be detected quickly and, if possible, remedied at short notice.

In a first step, BAM scientists, together with the Dutch Organization for Applied Scientific Research (TNO), built a two meter long bridge model in the laboratory and then created a digital twin of this bridge on the computer. Digital twins, i.e. computer models of real models, have long been used in Industry 4.0 to simulate and monitor the behavior of physical objects. By means of sensors that record every smallest change - forces and deformations - on the model and later on real bridges, the digital twin is continuously fed with data in the computer. Dr. Andreas Rogge, one of the project managers, explains, "Placing the sensors in meaningful locations is essential." The decisive advantage of the technology over the previous monitoring method is obvious: Even the smallest damage invisible to the naked eye in places that are not directly accessible with sensors can be detected in this way. "In principle, this gives you an overview of the entire structure," explains Rogge. "In contrast, during the walk-through inspections that are common today, only visually visible damage is detected and, if necessary, fitted with a sensor. This means that only defects that have already been detected are further inspected."

Video