In cooperation with the Slovak University of Technology, a new utility model has been developed, with the participation of scientists from the BUT. The Slovak Industrial Property Office registered the result entitled "Intelligent beam with the possibility of stiffness change" on 10 July 2023 as utility model No. 9819. In addition to a professor from our faculty (Prof. Ing. Rudolf Hela, CSc.), a team of authors - among others from the Faculty of Mechanical Engineering (Prof. Dr. Ing. Jiří Marek, Ph.D.) - participated in the result, DBA) and a team of authors from the Slovak Technical University: prof. Dr.h.C. Ing. Ľubomír Šooš, Ph.D., prof. Ing. Stanislav Žiaran, CSc., Ing. Viliam Čačko,  Ph.D., Ing. Ondrej Chlebo, Ph.D. and Ing. Marek Šooš, Ph.D.

The technical solution concerns the construction of an intelligent beam with the possibility of changing the stiffness. It is exceptional in its nature - technically it falls into the field of engineering and building structures.

The intelligent prestressed beam consists of a solid body with a blind full-space slot that divides the solid body into a buckling section and a face section. The thickness of the buckling section shall be less than the thickness of the face section, the plane of the solid slot being parallel to the plane of the buckling section of the solid body and the width of the solid slot being the same as the width of the solid body. A set of controlled compensating force members having a thermal expansion greater than the thermal expansion of the solid body and having one end in contact with the impingement part and the other end in contact with the front part of the solid body is disposed in the full-space slot. The solid body is connected to the base, wherein the full-space slot is terminated at one or both ends of the blank portion by a through hole having a diameter greater than the thickness of the full-space slot. The solid body is metal, concrete or composite. The compensating force members are thermally, mechanically, pneumatically or hydraulically controlled. The number, length and positioning of the compensating members depends on the particular case, with the length of the compensating force members being greatest in the open part of the full-space slot and gradually decreasing towards the bottom of the blind part of the full-space slot. The all-space slit is oriented vertically or horizontally.

The essence of the technical solution

The deformation of any load-bearing system of heavy machine tools is dependent on the cutting force components. This is transmitted to the contact point of the cutting tool and the workpiece and its increase deteriorates the machining accuracy. This is still commonly solved in practice by increasing the solidity of the machine structure, which at today's cast iron prices significantly increases the price of the machine. The proposed system of intelligent beams eliminates this problem considerably, in particular by the possibility to control the stiffness of the system by means of force compensating elements, which are located in the full-space slot and can be mechanical or hydraulic or thermal, which also eliminate the effects of temperature changes and the effects of thermal expansion on machining accuracy. The originality of this design also lies in the optimum and controlled elimination of the force from the cutting tool to the support system. This allows for increased cutting speeds, greater thickness of the removed stock and saving of tools.

Option to purchase a license

The utility model is hereby made available to potential licensees. Licensing normally takes place under normal terms and conditions. The major advantages of the assembly include applications in the manufacture of foundation beds and stands for heavy precision NC machine tools, as well as for special beams in the construction industry(e.g. simple bridge prefabrications or skeleton spans). The intelligent beam has the ability to rapidly change stiffness by controlling compensating force members and possibly compensating for the effects of temperature impact changes on volumetric temperature changes. It is assumed that the utility model could be used by companies focused on the production of precision heavy NC machines (horizontal, vertical milling machines, carousel lathes, etc... The result is intended mainly for the field of engineering production, or for use in the construction industry in the production of atypical beams, e.g. for single span bridges.

If you are interested in using it, please do not hesitate to contact the Technology Transfer Manager (MTT) who is the author of this article.