Energy and Dynamic Properties of Hydraulic Systems

The aim of the paper is to evaluate hydraulic systems in terms of energy and dynamic properties. There are flow and pressure losses that have influence on total efficiency of hydraulic systems. The systems are compared from lower effective to energy saving. There are described advantages and disadvantages of the systems in this work. Dynamic properties of the investigated energy saving Load-Sensing system were determined based on the system eigenfrequency. Dynamic behaviour of the system was performed by three different methods that were subsequently compared

Study of light transmission and noise attenuation properties of light active glass materials

Lighting and noise belong to important environmental factors that have an influence on human psyche, concentration, labour protection, sleep quality and so on. This paper is focused on study of light transmission and noise attenuation properties of light active glass materials, which are applied as window and door panels in residential buildings. The light transmission through tested materials was evaluated by means of the transmission coefficient from the illuminance ratio method. The material ability to dampen noise was determined based on the sound pressure level attenuation during sound propagation through the light active glass materials. Different factors, which have an influence on the propagation of light and noise through the investigated glass materials, were evaluated in this work. Finally, the effect of the light transmission through the tested light active glass materials on the daylight quality in a living room was mathematically simulated using Wdls 5.0 software

Study of carbon black types in SBR rubber: Mechanical and vibration damping properties

Styrene-butadiene rubber mixtures with four types of carbon black were studied in this paper. The mechanical properties, including the ability to damp mechanical vibration, were investigated, along with dynamical mechanical analysis (DMA). It has been found that carbon black types N 110 and N 330, having the largest specific surface area and the smallest particle diameter, provide a good stiffening effect. These particles have significant interactions between the rubber, resulting in good reinforcement. On the other hand, the carbon black N 990 type has a lower reinforcing effect and improved vibration damping properties at higher excitation frequencies due to higher dissipation of mechanical energy into heat under dynamic loading. The effect of the number of loading cycles on vibration damping properties of the rubber composites was also investigated in this study. It can be concluded that the abovementioned properties of the investigated rubber composites correspond to physical-mechanical properties of the applied carbon black types. © 2020 by the authors.Research Center of Advanced Mechatronic Systems project within the Operational Program of Research, Development, and Education [CZ.02.1.01/0.0/0.0/16_019/0000867]; NPU I [LO1504]; [IGA/FT/2018/008

Study of the sound absorption properties of 3D-printed open-porous ABS material structures

Noise pollution is a negative factor that affects our environment. It is, therefore, necessary to take appropriate measures to minimize it. This article deals with the sound absorption properties of open-porous Acrylonitrile Butadiene Styrene (ABS) material structures that were produced using 3D printing technology. The material's ability to damp sound was evaluated based on the normal incidence sound absorption coefficient and the noise reduction coefficient, which were experimentally measured by the transfer function method using an acoustic impedance tube. The different factors that affect the sound absorption behavior of the studied ABS specimens are presented in this work. In this study, it was discovered that the sound absorption properties of the tested ABS samples are significantly influenced by many factors, namely by the type of 3D-printed, open-porous material structure, the excitation frequency, the sample thickness, and the air gap size behind the sound-absorbing materials inside the acoustic impedance tube. © 2020 by the authors.Ministry of Education, Science, Research, and Sport of the Slovak Republic [KEGA 007TUKE-4/2018, APVV-19-0550]; European Regional Development Fund in the Research Centre of Advanced Mechatronic Systems within the Operational Programme Research, Development, and Education [CZ.02.1.01/0.0/0.0/16_019/0000867

Influence of rubber composition on mechanical properties

The purpose of this contribution is to investigate different mechanical properties of various types of rubber composite materials that were filled with carbon black nanofiller. The rubber composites were produced from three different basic rubbers. Moreover, the composites were produced with different volume concentrations of the basic rubbers including their various ratios. Mechanical properties of the tested rubber composites were investigated by means of tensile testing, Shore hardness, rebound resilience, mechanical friction, abrasion, viscoelastic behaviour and vibration damping measurements. It was found in this study that the rubber composition has a significant influence on the stiffness of the investigated rubber composites, and thus, on their mechanical properties. © 2021 Manufacturing Technology. All rights reservedRP/CPS/2020/004; CZ.02.1.01/0.0/0.0/16_019/0000867; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠM

Simulation of dynamics of system with hydraulic lines and linear hydraulic motor with mass load

This paper deals with the numerical simulation of dynamic properties of the system consisting of hydraulic lines and linear hydraulic motor with a mass load. The mathematical model is created using Matlab SimHydraulics software. Oil bulk modulus, elasticity and volumes of pipes and hoses play a significant role in this case. Mathematical models are verified on experimental equipment. Pressure and position responses during sudden stop of a moving cylinder are measured on this equipment. © Owned by the authors, published by EDP Sciences, 2013

Evaluation of bulk modulus of oil system with hydraulic line

The aim of the paper is to experimentally measure and ealuate bulk modulus of oil/steel pipe system and oil/hose system. The measurement was performed using experimental device on the basis of a measured pressure difference depending on time. Bulk modulus is evaluated from pressure change with known flow and volume of line. Pressure rise is caused by valve closure at the line end. Furthermore, a mathematical model of the experimental device is created using Matlab SimHydraulics software. Time dependencies of pressure for the oil/steel pipe system and the oil/hose system are simulated on this mathematical model. The simulations are verified by experiment. © Owned by the authors, published by EDP Sciences, 2013

Mathematical simulation and measurement of expansion of hydraulic hose with oil

Rad se bavi mjerenjem i matematičkom simulacijom širenja hidrauličnog crijeva, uključujući učinak modula stlačivosti ulja. Youngov modul elastičnosti hidrauličnog crijeva eksperimentalno je određen metodom ekspanzije i metodom kompresije. Modul elastičnosti hidrauličnog crijeva dobiven metodom ekspanzije određen je mjerenjem povećanja volumena ulja, sabijenog u ispitivanom crijevu nakon ekspanzije. Youngov modul elastičnosti hidrauličnog crijeva, dobiven metodom kompresije, određen je mjerenjem protoka ulja i porasta tlaka u hidrauličnom crijevu u odnosu na vrijeme. Modul stlačivosti ulja eksperimentalno je određen metodom ekspanzije i metodom kompresije ulja u čeličnoj cijevi. Hidraulični krug za simulaciju širenja ulja u crijevu i čeličnoj cijevi stvoren je primjenom softvera Matlab SimHydraulics. Povećanje volumena ulja nakon širenja u hidrauličnom crijevu i čeličnoj cijevi numerički je simulirano. Nadalje, vremenske ovisnosti smanjenja tlaka tijekom širenja ulja u hidrauličnom crijevu i čeličnoj cijevi numerički su simulirane. Rezultati matematičkih simulacija uspoređeni su s eksperimentalnim tijekom primjene Youngova modula elastičnosti crijeva i modula stlačivosti ulja određenih metodom ekspanzije i metodom kompresije.The paper deals with measurement and mathematical simulation of expansion of a hydraulic hose including the effect of oil bulk modulus. Young’s modulus of elasticity of the hydraulic hose is experimentally determined by expansion method and by compression method. The modulus of elasticity of the hydraulic hose obtained from the expansion method is determined by measurement of an oil volumetric gain, which is compressed inside the investigated hose after the oil expansion. The Young’s modulus of elasticity of the hydraulic hose obtained from the compression method is determined by measurement of oil flow and pressure increase vs. time in the hydraulic hose. The oil bulk modulus is experimentally determined by means of the expansion method and the method of oil compression in a steel pipe. A hydraulic circuit for simulation of the oil expansion from the hose and the steel pipe was created using Matlab SimHydraulics software. The oil volume increase after the expansion from the hydraulic hose and the steel pipe was numerically simulated. Furthermore, time dependencies of pressure decreases during the oil expansion from the hydraulic hose and the steel pipe were numerically simulated. Results of the mathematical simulations were compared with the experiment while using the Young’s modulus of elasticity of the hose and the oil bulk modulus that were determined by the expansion method and by the compression method

Effect of conditioning on PU foam matrix materials properties

This article deals with the characterization of the thermal-induced aging of soft polyurethane (PU) foams. There are studied thermal and mechanical properties by means of thermal analysis, tensile, compression and dynamic mechanical vibration testing. It was found in this study, that the increasing relative humidity of the surrounding atmosphere leads to the initiation of the degradation processes. This is reflected in the observed decreased mechanical stiffness. It is attributed to the plasticization of the PU foams wall material. It is in agreement with the observed increase of the permanent deformation accompanied simultaneously with the decrease of Young's modulus of elasticity. The latter phenomenon is studied by the novel non-destructive forced oscillations vibration-damping testing, which is confirmed by observed lower mechanical stiffness thus indicating the loss of the elasticity induced by samples conditioning. In parallel, observed decreasing of the matrix hardness is confirming the loss of elastic mechanical performance as well. The effect of conditioning leads to the significant loss of the PU foam's thermal stability.European Regional Development Fund in Research Centre of Advanced Mechatronic Systems project within Operational Programme Research, Development and Education [CZ.02.1.01/0.0/0.0/16_019/0000867]; Internal Grant of Palacky University in Olomouc [IGA_PrF_2021_031]CZ.02.1.01/0.0/0.0/16_019/0000867; Univerzita Palackého v Olomouci: IGA_PrF_2021_03

Materials characterization of advanced fillers for composites engineering applications

Four different minerals were investigated; hollow spheres of calcium carbonate, platy mica, needle like wollastonite and glassy perlite and characterized via iGC for surface energy, Freeman powder rheology for flow characterization, cyclic uniaxial die compaction for modulus of elasticity and frequency dependent sound absorption properties. Particle surface energy and particle shape strongly affected the packing density of powder beds. In the case of higher porosity and thus lower bulk density, the powders acoustic absorption was higher in comparison with higher packing density materials. Surface energy profiles and surface energy distributions revealed clear convergence with powder rheology data, where the character of the powder flow at defined consolidation stresses was mirroring either the high cohesion powders properties connected with the high surface energy or powder free flowing characteristics, as reflected in low cohesion of the powder matrix.Ministry of Industry and Trade of the Czech Republic [OP PIK CZ.01.1.02/0.0/0.0/16_084/0010256