ANALYSIS OF STATIC STIFFNESS OF MACHINE TOOLS FOR RAILWAY AND SHIPBUILDING INDUSTRIES

The article presents static stiffness investigation of a rather specific group of machine tools characterized by a unique construction type which are made for railway and shipbuilding industries. Machines of that type are rarely tested in terms of their static stiffness, so consequently the knowledge about their static stiffness properties is fairly limited. The investigation was conducted involving two methods, traditional (conventional) one and the other originally developed method using dynamically changeable signal (DDSS). The results obtained represented stiffness characteristics and stiffness indicators. The static stiffness tests of the machine tools presented in the article are very rare. Therefore, in this case, the knowledge base is very poor. Based on the results obtained, the machining accuracy can be predicted. In many cases, the obtained results are the only source of information needed to validate FEM calculation models, compare similar machines, verify and optimize the stiffness of the structure at the design stage. In addition, due to the lack of appropriate standards for conducting this type of research, the presented unique procedures are helpful for subsequent researchers of this issue.