The invention concerns a damping element (10, 108) for absorbing mechanical excitations comprising a container (14, 112, 114, 116) encapsulating a viscoelastic material, wherein the container (14, 112, 114, 116) is pressurized to a pressure level (p), at which said damping element's (10, 108) frequency (50) for absorbing a maximum energy (49), substantially matches a frequency of the mechanical excitation (56). The invention further relates to a method for producing a damping element (10, 108) as well as different uses.
F.32 International patent
COBISS.SI-ID: 12444187Patented solution utilizes all possible energy dissipation mechanisms and represents an optimal (ultimate) solution for the novel damping system. Such damping elements that are built in railway sleeper consist of elastomeric granular material, which is encapsulated in a flexible glass (carbon or basalt) fiber tube. Granular materials when excited beyond a certain level of stress flow similarly as liquids while maintaining all properties of a bulk material. The macroscopic flow of particles further expands the energy dissipation capability of granular materials. Hence, micro- to macro-size multimodal elastomeric granular material may be used as a pressurizing media (similar as air in tires) to impose hydrostatic pressure on itself, and change frequency dependence of its own energy absorption properties. With proper adjustment of pressure we also adjust the stiffness of the damping element (similar as with air in tiers). In addition, the proposed particle-filled damping elements provide greater energy dissipation, since when granular materials are deformed there is relative motion of particles; such motion causes additional energy dissipation through friction. Our proposed solution consists of micro- and macro-sized particles. Smaller particles lead to more surface area per unit volume, which increases the magnitude of frictional dissipation energy caused by particle-particle interaction; while larger particles will allow macroscopic flow, as described above.
F.32 International patent
COBISS.SI-ID: 1244469933rd Danubia Adria Symposium was organized by our group and it highlights the latest innovations, R&D and industrial activities in area of experimental methods in mechanics. It also provides forum for discussion of the latest research results, new developments of concepts and technologies, proven techniques, as well as practical applications and standardization of the experimental methods in mechanics. Main topics on this year's simposium were: • Structural analysis: experimental tests, structural health monitoring, system identification, damage assessment, self-adaptive structures • Material characterization and testing: smart materials, residual stress, fatigue, fracture, creep • Practical applications and case studies • Biomechanics: biomaterials, biomechanics, medical and orthopedic devices, biofluid mechanics • Instrumentation: new sensors and actuators, advanced measurement systems, validation and reliability of instrumentation • Complex systems, integration of mathematical/numerical methods with experimental mechanics • Recent developments in international standardization and technical regulations • Mechanics of time-dependent materials • Polymer processing
B.01 Organiser of a scientific meeting
COBISS.SI-ID: 286319616Asphalt mixtures have a prevailing role in affecting pavement performance. Since bitumen, which is a main component in asphalt mixtures, exhibits viscoelastic behavior, some measures for improving time and temperature stability of the mixtures are required. Polymer additives are used as asphalt modifiers with the aim to improve its thermo-mechanical behavior and functionality. Addition of polymeric powders, which form a rigid network structure in a highly viscous continuous phase of the base bitumen, significantly improves mechanical (rheological) properties of modified bitumen. There is a constant interest in the asphalt industry in new additives or techniques, which enable economically and environmentally optimized manufacturing of asphalt products. The in-situ determination of mechanical properties of pavement materials is of great importance in pavement management system. The information is needed in order to (i) properly design the constructed layers, and (ii) locate and characterize zones of weakness. Pavement structures, assumed as semi-infinite multi-layered medium, require spectral analysis of surface waves, especially at low frequency range. Nondestructive testing (NDT) technique is usually used to obtain the thickness and stiffness properties of different layers in a pavement. The technical development is based on a theoretical study of wave propagation in pavement structures as well as on reported difficulties experienced with existing methods. The contribution of surface waves is significant for a number of applicative problems in paving industry, in particular, the resonance phenomena caused by moving loads. Information about mechanical properties and layer thicknesses of pavement profiles is important for their proper maintenance or rehabilitation. Due to their efficiency and economy, non-destructive methods are widely used for assessing the structural performance of layered systems, and therefore provide a valuable tool in pavement design and management. In combination with improvement of asphalt properties by using modifiers, development of NDT methods might help manufacturers in introducing measures helping in improvement of road functionality.
B.04 Guest lecture
COBISS.SI-ID: 1176054In the paper published in Planinski vestnik we are dealing with effect of mass on response of climbing ropes. In the work there are explained theoretical characteristics of falls with climbing ropes and calculation of key parametrs. The measurements are preformed on samples of Beal Booster III climbing ropes on non-standard test rig in Center for experimental mechanins Ljubljana. On the base of experiments data analysis is made. The resoults reprisent analysis of force, maximal elongation, energy dissipation and acceleration when the rope is loaded with the falling mass. The resoults show us that the important parameter for the loading of climbers and that it should be considered with the development of new standards.
F.35 Other
COBISS.SI-ID: 14027547