The animated photo sequence shows an attempted launch of the TU Delft V3 kite from an upside-down hanging position on 2 August 2012 at the former airfield Valkenburg, Leiden, Netherlands. While the upswing of the kite towards the upright position proceeds well, the tether suddenly disengages from the mast head, at 15 s into the video. Within only 1 s, the kite accelerates in downwind direction, pulling the disengaged tether into a new tensioned state, which is the straight line connecting the kite with the ground station placed upwind of the launch mast. During this rapid straigthening of the tether, the entire kite, consisting of wing bridle line system and kite control unit, is pitching up, yanking the relatively heavy control unit upwards. Once the tether is tensioned, it takes only a fraction of a second until the weak link breaks due to overload. As a result, the pulling force of the detached kite immediately shifts to the safety line, which at this point in time remains the only physical connection between the kite and the tether. The sudden force increase in this line activates the integrated progressive-tearing energy absorber, which is visible from the scattering fabric debris (starting at 16 s into the video) and the kite again accelerating in downwind direction. With the breaking of the weak link, the kite control unit is catapulted in radial direction towards the wing and eventually caught by the bridle line system. This ballistic event leads to an irreversible collapse of the wing. Secured by the safety line, the parachute-like assembly of curled-up wing and kite control unit slowly descends and hits the ground about 27 s into the video. This launch attempt was also covered by data recording, and by two different GoPro video cameras, of which one was positioned on the ground, next to the launch mast, and the other one taped to the leading edge tube of the kite, looking down at the kite control unit. The 39 photos capturing this launch attempt were shot with a Nikon D40X in irregular intervals. The photos were assembled into a video using the precise time information available for each photo from its metadata. Because the time duration between the first and the second photo of the sequence is about 10 s, the animation does not resolve the first 10 s of the upswing. Also, the absolute time setting of the camera was incorrect, which is why the time information of the generated video file was synchronized with the absolute time available from the data recording. The creation date of the video was set to the launch time 18:27:18 such that the weak link ruptures about 16 s into the video, at 18:27:34.


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    Titel :

    Rupture of the weak link during a mast-based launch attempt of the V3 kite: Animated sequence of photos taken on 2 August 2012 from the ground


    Untertitel :

    Experiment/Model Test




    Erscheinungsdatum :

    2020-01-01


    Format / Umfang :

    13 MB, 00:00:41:00


    Anmerkungen:

    Originalton ohne gesprochenen Text
    Original sound, no spoken text



    Medientyp :

    Audiovisuelles Material


    Format :

    Audiovisuelles Material


    Sprache :

    Unbekannt





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