Issue 22

D. Gentile et alii, Frattura ed Integrità Strutturale, 22 (2012) 85-92; DOI: 10.3221/IGF-ESIS.22.09 85 Design and realization of a multisamples rotating high cycle fatigue machine Domenico Gentile DICeM – University of Cassino – via G. Di Biasio, 43 – 03043 Cassino, Italy Massimo Martorelli DiME – University of Naples Federico II – School of Engineering, P.le V. Tecchio 80 - 80125 Naples, Italy massimo.martorelli@unina.it A BSTRACT . In this work the design and the technical characteristic of a Moore rotating bending machine are presented. The machine has been realized at the University of Cassino in order to run tests on multiple specimens at different temperature. The user can choose independently the load and the temperature for each specimen. The machine has been designed to produce in short time a several numbers of data of materials fatigue strength at low costs. The machine is in assembling step at the Laboratory of Industrial Design of the University of Cassino. K EYWORDS . Fatigue; Wholer; Test machine; Product design process. I NTRODUCTION atigue research has been conducted on a multitude of testing machine ranging from rotating bending loading, axial loading, repeating bending loading and torsional loading. The design varies according to the nature and combination of load and components, to the type of fatigue test (high cycle, low cycle, thermal fatigue), to the scale (small specimens, full scale components). In this work the design of a low-cost and reliable rotating bending fatigue testing machine that meets the following criteria has been issued: 1. Minimum mass so that high cycle fatigue testing can be done on this machine. 2. Constant bending moment on specimen throughout testing. 3. Up to 5 samples tested in the same time. 4. Commercially available components adopted where possible. 5. Designs, material selection, machinery specifications for unavailable components. 6. Possibility to update easily the machine. 7. Possibility to run tests at different temperature The idea is to realize a low cost machine that should be extremely adaptable. Rotating machine configuration is one of the simplest and efficient in order to test a sample by a time variable load under constant amplitude, Fig. 1. First machine has been design by Wöhler [1]. The simplest configuration has been proposed from Moore and Krouse [2] that reached speed of the order of 30.000 rpm. The machine, using four point bending system, allows to load the sample with a constant stress on the full measure zone. Leher [3] and next Moore developed solutions in this way. This F