Method for producing prestressed structures and structural parts by means of SMA tension elements, and structure and structural part equipped therewith

A method for producing a prestressed structure via one or more tension elements comprised of a shape memory alloy for reinforcing of a structure and having a polymorphic and polycrystalline structure, which, by increasing its temperature, is able to be brought from a martensitic state to a permanent austenitic state, said method comprising the steps of:

• extending on the structure a tension element that is guided around a corner or a curvature of the structure;
• wherein the tension element is secured to the structure by at least one of, or a combination of, the following:
• a) the tension element is attached to at least one end anchor that penetrates into the structure;
• b) the tension element wraps around a structure as a band, wherein two ends of said tension element are connected to each other via a tensile connection;
• c) the tension element wraps around the structure as a band, wherein two ends of said tension element are separately connected to the structure via at least one end anchor or at least one intermediate anchor which penetrates into the structure;
• or
• d) the tension element overlaps or crosses on itself at least once in a clamping manner;
• heating the tension element, utilizing an active and controlled heat input in order to contract the tension element and generate a permanent tension;
• wherein the heating of the tension element is performed via electric contacts on the end regions of the tension element, by applying a voltage to the tension element, such that the electrical resistance of the tension element causes the tension element to increase in temperature and transition from the martensitic state to the permanent austenitic state, such that the tension element exerts a permanent or residual tension up to fracture load of the structure.