Simulation calculations to verify the past
In 1967, at the high alpine border pass between East Tyrol (Austria) and Cadore, in the Italian province of Belluno, an explosive attack was carried out on the 220KV electricity pylon no. 119 on the Porzescharte. The attack led to a serious diplomatic crisis between Austria and Italy and is considered one of the most dramatic incidents of the South Tyrol conflict. Together with Prof. Dr. Ing. Harald Hasler MSc MA, court-certified expert for explosives, blasting technology, mines and forensics, Merke CAE Solutions has recreated the past using engineering simulation calculations.
Simulation can not only make predictions, but also verify the past. This is the core of damage simulation, but it also applies to criminal cases involving explosives that are steeped in history. The background to the investigation of the blast is that Prof. Dr. Ing. Harald Hasler MSc MA carried out extensive scientific field tests and experiments as well as the most precise reconstructions with various explosives, which are described in detail in his book ‘Wissenschaftliche Neubeurteilung der Rechtssache “Porzescharte 25. Juni 1967”’. Contradictions came to light which made it clear that the events could hardly have happened as described in the court documents.
Simulating the blasting process
The simulation task was to realistically simulate the behavior of the 220KV electricity pylon no. 11 during and after a blast using the finite element method (FEM). The aim was to investigate how the structure behaves under its own weight after targeted destruction of individual joints. The question was therefore whether and how the mast could fail as a result of one or more successive blasts and ultimately topple completely to the ground. Using the finite element method (FEM), it was possible to determine that the electricity pylon initially retained its structural integrity after the first targeted blast. It was not until a second blast that a decisive structural failure occurred.
Verifying the simulation
In an extended simulation, the complete tilting of the mast down to the ground could also be realistically represented. Previously occurring numerical instabilities were successfully eliminated by finer modeling with shell elements. The results of the investigation support the assumption that a two-stage blasting process was necessary to bring about the complete failure, i.e. the toppling of the mast. The FEM simulation thus supports the assumptions of Prof. Dr. Ing. Hasler MSc MA that the alleged detonation of the 119 electricity pylon with only a single explosive charge, installed in a night-and-fog operation, could hardly have happened in this way.
The attack led to a serious diplomatic crisis between Austria and Italy at the time and is considered one of the most dramatic incidents of the South Tyrol conflict. There is also debate as to whether the incident may have been deliberately instrumentalized by Italy for political purposes.
Digital simulations correspond to reality
"The project impressively demonstrates what FEM simulations are capable of. As physics is digitally mapped in a realistic way thanks to high computer performance and expertise, simulations have been providing valuable services in product development and damage analysis for years. This time also on a historic scale," says Dipl.-Ing. (TU) Stefan Merkle, Managing Partner of Merkle CAE Solutions GmbH. "When experiment and simulation go together, many variants can be investigated more efficiently and safely than through pure test operation. With this in mind, Prof. Dr. Hasler MSc MA and Merkle CAE Solutions will continue to pool their expertise, be it in the blasting of buildings or the coordination of dummies and explosions in field tests."
