637. EXPERIMENTAL RESEACH OF STEEL ROPE INTEGRITY PROBLEM. V.BUČINSKAS, E. ŠUTINYS, V. K. AUGUSTAITIS  VIBROENGINEERING. JOURNAL OF VIBROENGINEERING. JUNE 2011. VOLUME 13, ISSUE 2. ISSN 1392-8716 312 637. Experimental research of steel rope integrity problem V. Bučinskas 1 , E. Šutinys 2 , V. K. Augustaitis 3 1 Vilnius Gediminas Technical University, Department of Machine Building, J. Basanavičiaus str. 28, LT-03224 Vilnius, Lithuania E-mail: vytautas.bucinskas@vgtu.lt; 2 ernestas.sutinys@vgtu.lt; 3 vytautas.augustaitis@vgtu.lt (Received 11 March 2011; accepted 15 May 2011) Abstract. This paper is dedicated to treatment of a problem of a steel rope diagnostics. Research was carried out in order to reveal possibilities of diagnostics of steel rope integrity by virtue of dynamical properties of tensed steel rope in a special test rig, which was designed and fabricated for this particular research work. Excitation of the considered system was accomplished by means of a special shaker, which was connected to the rope body. Vibration measurements were performed with respect to the test rig frame for the whole rope to detect the broken wire. During experimental research the efforts were made to excite the broken wire of the rope through the whole rope. Another series of experiments were conducted in order to determine the dynamic response of the wire to forced vibration of the rope with the constant amplitude of rope vibrations. In addition, attempts were made to define the influence of rope tension onto resonant frequency of the broken wire. Results of research are presented as spectrums of forced vibrations in a frequency range of interest. Major experimental findings are summarized by the conclusions. Keywords: rope, integrity, defects, diagnostics, dynamical properties. Introduction Steel ropes are widely used in technical design and frequently implemented as flexible link in various machines, installations and equipment. Flexibility and one sided force transmitting makes them common in many applications, but mostly they are used for lifting devices and load carrying. There are some installations, where ropes are critical elements – like lifts, rope trains, funiculars, etc. Ropes are widely used for static load transmission – tensing towers, bridges, electric lines [1, 4] as well as ropes compensating motion of truss elements, sharing structure loads in the case of dynamic of structures and so on. Due to extensive application of ropes as important linkage, a problem of proper care and early quality diagnostics became a key for safe and efficient exploitation of the machinery. Defect localization in the rope is complicated because of wire dimensions in length – for example, 5 storage house lift is equipped with a minimum of 2 sets of ropes with length of ca. 60 m. Recent tendencies are to use ropes of smaller diameter due to smaller dimensions of the equipment and smaller pulleys increases extent of diagnostics even more. Modern rope consists from 3 parts (Fig. 1): core, strand, strand center and the wire [1, 3]. Steel rope strands and wires have unified shape and are produced from high quality steel. Strands are wired in the same or in the contrariwise direction to wire rotation, depending on type of rope. Core of rope is produced from the synthetic fiber and is filled with lubricant, which lubricates wires of the rope during tension and rope operation.