Abstract: Disclosed is a distance measuring system for measuring distance of a first transceiver from second transceivers, comprising the first transceiver having a first time zone, a second transceiver having a second time zone, and a control unit having a control-unit time zone. The second transceiver ascertains a time-zone relationship between the second transceiver and the first transceiver, and transmits the time-zone relationship to the control unit. The control unit receives the time-zone relationship, and ascertains, using the received time-zone relationship, a time-zone relationship between the control-unit time zone and the first transceiver. The first transceiver transmits at a defined instant in time or for a defined time period of the first time zone a distance measurement command to the second transceiver. The first transceiver transmits a measurement signal at a further defined instant in time, and the second transceiver switches from an inactive into an active receiving or measuring state.

Abstract: A twist element for a bearingless rotor is made mostly of composite fiber material and has a cross section with a substantially symmetric, flattened shape that has approximately the contour of a horizontal, central section of a double cone. In addition, a bearingless rotor having at least one such twist element, and a rotorcraft, particularly a helicopter, having at least one rotor with at least one such twist element are provided.

Abstract: Active connection element for connecting at least two structural components with a first end with a first connection area assigned to the first structural component and a second end with a second connection area assigned to the second structural component, a load-diminishing intermediate section through which intermediate section the flux of force between the first and second connection areas extends when the connection element is loaded, in which at least one controllable extension actuator having at least a piezo stack is arranged parallel to the intermediate section. When operated, the piezo stack extends the connection element at least in the area of the intermediate section in a controlled manner in order to actively suppress or insulate vibrations between the structural components. A prestressing device having a prestressing element exercises a compressive prestressing onto the piezo stack.

Abstract: A twist element for a bearingless rotor is made mostly of composite fiber material and has a cross section with a substantially symmetric, flattened shape that has approximately the contour of a horizontal, central section of a double cone. In addition, a bearingless rotor having at least one such twist element. and a rotorcraft, particularly a helicopter, having at least one rotor with at least one such twist element are provided.

Abstract: Active connection element for connecting at least two structural components with a first end with a first connection area assigned to the first structural component and a second end with a second connection area assigned to the second structural component, a load-diminishing intermediate section through which intermediate section the flux of force between the first and second connection areas extends when the connection element is loaded, in which at least one controllable extension actuator having at least a piezo stack is arranged parallel to the intermediate section. When operated, the piezo stack extends the connection element at least in the area of the intermediate section in a controlled manner in order to actively suppress or insulate vibrations between the structural components. A prestressing device having a prestressing element exercises a compressive prestressing onto the piezo stack.

Abstract: A running gear for a rail vehicle having sprung longitudinal members of plastic, connected to one another by means of a cross-member structure and at their free ends to axle-boxes for rail wheels. In order to obtain optimal stability of the wheelset guidance with reduced loading of the sprung longitudinal members, the longitudinal members each has at least two flexural springs between the ends of which in each case an axle-box is fixed in symmetrical arrangement.

Abstract: A composite structure (3) includes a piezoelectric element (1) sandwiched between fiber composite panels (2). The composite structure can be used as an actuator element. In a method for producing the composite structure, the fiber composite panels are pre-stressed and pre-strained by applying respective pre-stressing forces (F.sub.1, F.sub.2) in opposite directions along two substantially perpendicular axes in the plane of the panel. The pre-stressed and pre-strained condition of the fiber composite panels (2) is maintained, while the panels are adhesively bonded (5) surfacially onto the piezoelectric element (1). After the bonding is completed, the pre-stressing forces are removed from the fiber composite panels. As a result, in the finished composite structure (3), the fiber composite panels (2) are under internal tension, while the piezoelectric element (1) is under internal compression. The pre-stressing forces (F.sub.1, F.sub.