# Upgrade of the Universal Testing Machine for the Possibilities of Fatigue Tests in a Limited Mode
## 3 Examples of Ways and Reasons for Upgrading in Technical Practice
The equipment also allowed multiple specimens to be tested simultaneously, thus reducing the time required to obtain the required complete set of fatigue characteristics. According to its designers, the equipment thus designed represents a reasonable cost alternative compared to conventional but far more expensive industrially manufactured servo-hydraulic testing machines. Another example of upgrading legacy test machine infrastructure according to [11] was the engineering design and implementation of an information system based on the Internet of Things (IoT). It was designed to remotely, collect, store and process information on the number of mechanical cycles performed for a group of legacy existing fatigue testing machines in the automotive industry for component manufacturing. Important was the possibility of automatic detection of the end of fatigue tests, thus achieving a more efficient utilization of the testing machines, according to the authors' data at a level of more than 25%. The electromechanical cycle count sensors were replaced by electronic sensor modules in the role of so-called clients with a newly developed Ethernet interface, working with a free Linux server and a web application framework. The results achieved were comparable to the manual data collection method. This was a relatively very affordable upgrade of older test machines without the need to buy expensive industrial communication systems. The work [12] addresses the issue of high cost and how this can be addressed, where the range of cost for a typical fatigue testing training device is between USD 10,500 and USD 32,500. These devices are essentially adaptations of the [PERSON] methodology testing machines with a price level of even more than 150,000 USD. Therefore, the author is looking at ways to produce affordable and fully functional versions of the equipment with appropriate test methodologies that will also provide reliable results. In contribution [13], a description of a newly developed simple test device for testing the dynamics of fatigue crack propagation is given. The apparatus, capable of high frequencies up to 4 kHz, allows to load the test specimen with inertial forces up to 2.9 kN, with their arbitrary course, at a value of 100 kg payload. The base of the fatigue vibration machine is a sliding table mounted on a granite base, providing a solid base for stability of the set parameters. An electromagnetic vibration unit from Ling Dynamic Systems, model V722, with a clutch that also allows for angular deflection, was chosen for the drive. According to the author's own evaluation, such a device can bring significant cost reductions compared to other comparable test rigs, e.g., of the Wiercigroch design. In [14] by [PERSON] et al., an example of a test machine upgrade is given with the design of a test fixture capable of performing high-cycle multiaxial fatigue tests. The newly developed test chain allows to combine bending and torsional stresses and to perform fatigue tests at high frequency up to 50 Hz. The loading itself can be proportional and non-proportional, where the direction of the principle stress can be varied during the cycle. Proportional loading here means cyclic bending loading and non-proportional loading is cyclic loading combining bending and reverse torsional loading. Strain gauge sensing of the quantities is part of this measurement chain and the digitization is realized by the application of an electronic control unit and an I/O A/D PC card. Upgrade processes of a similar device, which is also the subject of this paper, can be implemented by modifications, e.g., according to [15]. Its essence was the extension of the device with a multifunctional measuring card PCA 1408 (ADICOM) with Control Panel application software, strain gauge control panel UPM 60 from HBM and a digital caliper. A major contribution to the upgrade of the entire device was its digitization. This is because the application and control test software allowed customization for the user's needs.