Effect of external excitation on dynamic characteristics of vibration isolating table

Abstract

Article citation info: IntroductionMost of metrological instruments are sensitive to low-frequency mechanical vibrations and higher frequency -acoustic noise. These oscillations can occur from both outside and inside of the building, i.e. from passing automobiles, wind, heating, ventilation and air-conditioning equipment, and these building vibrations effect on laboratory equipment operation as well. The possibility and method of time varying vibration decomposition are discussed in the scientific workof professor Radkowski [11].Honeycomb sandwich structures are currently being used in various engineering solutions, both within and outside of aerospace engineering. Lightweight honeycomb materials can be used in the construction of composite panels, shells, and tubes with high structural efficiency. The dynamic characteristics of Multilayer Polyurethane foam glass/fiber composite sandwich panels have been determined through Experimental Investigations by Havaldar and others [4].Sandwich shell structures including metal alloys and composites are being increasingly applied to many aircraft, automobile and construction industries due to their lightweight and highly load carrying capacities. Furthermore, the use of cellular cores for panels and shells not only can further reduce the structural weight, but also potentially possess superior heat dissipation, vibration control and energy dissipation characteristics. Filament winding and twice co-curing processes were proposed to make a carbon fiber reinforced composite (CFRC) sandwich cylinder with Kagome cores. Axial compression was carried out to reveal the stiffness and load capacity of the fabricated sandwich cylinder. Compared with the stiffened cylinder with similar dimensions and mass, the sandwich cylinder is shown to be stiffer and stronger by several times [3]. Linear and nonlinear analysis using the ABAQUS finite element is described in paper [15]. Some mechanical properties such as compression, bending, impacting and vibration have been reported by many scientists worldwide. Analytical calculation methods have a clear advantage when designing multi-layered composite cylindrical shells. Compared to Finite Element Methods (FEM) they enable more precise physical interpretations and weighting of the different design variables to be made and, hence, significantly facilitate problem-specified parameter studies and sensitivity analysis [5]. Sandwich cylindrical shells are the major components of aerospace apparatus structures [17]. Nevertheless, an analytical investigation was carried out to examine the response of CFRC sandwich cylinders with lattice cores.Researchers Xiong et al [20] manufactured sandwich-walled cylindrical shells with aluminium pyramidal truss core of constant curva-JUREVICIUS M, TURLA V, BUREIKA G, KILIKEVICIUS A. Effect of external excitation on dynamic characteristics of vibration isolating table. Eksploatacja i Niezawodnosc -Maintenance and Reliability 2015; 17 (2): 260-265, http://dx

Analysis of Dynamic Parameters of a Railway Bridge

“…In the theoretical model [24][25][26][27], errors of measurement of digital vibration signals are assumed to be random and systematic.…”

Research of Dynamics of Low Floor Bus / Žemagrindžio Autobuso Dinaminiai Tyrimai

“…Šie tyrimai atskleidė, kad įvairūs konstrukciniai sprendimai ir eksploatavimo sąlygos daro nemažą įtaką automobilių kelio dangai perduodamoms dinaminėms ratų apkrovoms ir važiavimo metu sukeltiems virpesiams, perduodamiems vairuotojui/ keleiviui transporto priemonėje (Lin et al 1994). Virpesių analizė plačiai naudojama mechaninėms sistemoms vertinti (Kilikevičius 2015;Jurevičius et al 2015). Žinoma, kad prie dinaminės ratų apkrovos ir važiavimo kokybės labai prisideda tokie veiksniai: a) eksploatavimo sąlygos: kelių nelygumai, greitis ir didžiausias pakrautos transporto priemonės leistinas svoris; b) įvairūs konstrukciniai sprendimai, susiję su ašinėmis apkrovomis, ašių konfigūracija, pakabos ir padangų statinėmis ir dinaminėmis savybėmis.…”

Effect of External Excitation on Dynamic Characteristics of Vibro-Isolating Table

“…This has almost no effect, because it would be very unusual to find large oscillations of 0.5 Hz [6,7]. The quasi-zero stiffness system is compact and lightweight [8,9].…”