<p>The present paper deals with the fatigue strength of large diameters tension rods with metric, cut thread of S460N steel grade. In total 36 fatigue tests equally categorised to 4 experimental series with two varying parameters (i) size diameter, M68 and M100, and (ii) surface treatment, hot-dip galvanized or as-rolled, were performed by the Institute of Structural Design at the Material Testing Institute of the University of Stuttgart. The tests conducted herein for rods of metric, cut threads validated the detail category 50 as well as its factor for size effect, while being slightly on the safe side.</p><p>Additionally, one specimen of M100 as-rolled tension rods, equipped with six miniature strain gauges placed on the thread root of the upper tension rod was tested up to 4,8 MN of quasi-static monotonic tension load- ing until complete failure. Strain concentration factors for the thread root of the M100 tension rod were calculated.</p>

Im Vorhaben „Zyklische Bemessung von Zugstäben mit Endgewinden“ sind umfangreiche Untersuchungen an Zugstäben verschiedener Herstellungsarten (geschnitten, gerollt, mit und ohne Feuerverzinkung) durchgeführt worden. Dabei wurden die Durchmesser M16, M48, M68 und M100 untersucht. Die Ergebnisse der 214 Ermüdungsversuche zeigen erhöhte Ermüdungsfestigkeiten für gerollte Zugstäbe. Für geschnittene Gewinde wird der Kerbfall 50 bestätigt. Der Einfluss von Produktions‐ und Montagetoleranzen wurde mit dem Kerbdehnungskonzept untersucht. Auf Basis der Untersuchungen wird ein Vorschlag der Einordnung des Kerbdetails „Zugstäbe mit Endgewinden“ aus Baustahl unter Berücksichtigung des Herstellungsverfahrens und einer Feuerverzinkung formuliert.

“Disasters” such as seismic events, impact or fire loading to structural elements of crucial importance highlight the significance of structural design for robustness. Consequently, exceptional load scenarios are to be considered. The question whether the joints of structures designed according to the current version of Eurocodes have adequate load bearing and defor­mation capacity for such load cases arises. The “alternate load path method” plays a key role in structural design for robustness. By using this design approach, redistribution and distribution of the existing and additional loads, respectively, to the intact structural elements should be enabled after a local failure such as “loss of a column”, preventing so the progressive collapse of the structure. In order to pursue the aforementioned goal, sufficient bearing as well as rotational capacity of the joints are required. In particular, for exceptional events, change of the moment’s sign in the area of the joints is often to be observed. However, until today, attention has been paid mainly to the response of composite joints under negative moments. Herein, besides this load case, the corresponding one of positive moments is investigated as well as the development of a membrane action that supports the load redistribution but requires a tension force capacity of the joints. Experimental research for the load case “loss of a column” was undertaken on both single composite joint specimens and composite frames. Also, an integrated design method, the beamline method, is analysed and constructional recommendations for design of ductile compo­site joints were developed and are herein presented.