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Free Vibration and Damping Characterization of the Biocomposites
Published in Senthil Muthu Kumar Thiagamani, Md Enamul Hoque, Senthilkumar Krishnasamy, Chandrasekar Muthukumar, Suchart Siengchin, Vibration and Damping Behavior of Biocomposites, 2022
Vibration is a complex cyclic process that involves periodic cyclic displacement of a particle around an equilibrium position. Vibration is generally classified as free vibration and forced vibration. Both these types of vibration dissipate energy due to a change of energy from the kinetic potential energy of vibration in every successive cycle. Vibration analysis is mainly done to check for the anomalies caused by vibration in the machinery using piezoelectric sensor or accelerometer. The main parameters involved in any study of vibrations are frequency, amplitude, and acceleration. Most damping vibration analyses fall under the following techniques: (a) determination of amplitude decay in free vibration, (b) determination of resonance curve during forced vibration, (c) forced vibration hysterics loop study in the stress–strain curve, (d) calculating the amount of energy absorbed during forced vibration, and (e) determination of sound wave propagation constants. Method “a” and “b” are the most preferred methods for testing among the other techniques.
Mechanical System Design (Strength and Stiffness)
Published in Seong-woo Woo, Design of Mechanical Systems Based on Statistics, 2021
The change of Tf with the frequency ratio r=ω/ωn is displayed in Figure 6.20. In order to attain isolation, the force transmitted to the base is required to be less than the excitation force. It can be seen that the forcing frequency has to be greater than the natural frequency of the system in order to attain isolation of vibration.
Generator Driver Applications and Selection
Published in Neil Petchers, Combined Heating, Cooling & Power Handbook: Technologies & Applications, 2020
Another common concern is the level of vibration associated with reciprocating engines. Torsional and lateral vibration may be eliminated or reduced to safe levels by appropriate shaft coupling applications and rotor balancing combined with appropriate provisions to isolate vibration from surrounding structures.
Online condition monitoring system for rotating machine elements using edge computing
Published in Australian Journal of Mechanical Engineering, 2023
N. D. Pagar, S. S. Gawde, S. B. Sanap
Vibration measurement is done via a piezoelectric sensor (accelerometer), as they are beneficial in detecting the large forces having relatively small displacement. It has good frequency response and easier to handle because of its compact size. A PZEM004T is a single-phase voltage, current and power sensor used for current measurement as it also contributes to the decision while condition monitoring. The sensing component is a precise AC current transformer coil with an output of 100A/100 mA. Temperature sensor (MAX6675) is used for temperature measurement because any fault that initiates cause friction, which affects the temperature of the equipment. All three sensors are interfaced with the STM32F4 microcontroller board via RS-485 cable. STM32F4 is 32-bit ARM Cortex M4 that takes fewer instruction cycles to execute a function due to its wider data bus (fetch, decode, and execute instructions). This allows to make a FFT with a few simple steps. STM32 series provide instructions for signal processing. It is a high-performance microcontroller with low cost and power consumption. The sensors are connected to the microcontroller circuit using RS-485 cable. It is a differential cable, so the noise-free data transferred through it is not affected by the ground voltage. RS-485 can handle up to 32 devices at once and can travel up to 1200 m, which single-ended cables cannot.
Validation and simulation of cavitation flow in a centrifugal pump by filter-based turbulence model
Published in Engineering Applications of Computational Fluid Mechanics, 2022
Weidong Cao, Zhixiang Jia, Zhenjiang Zhao, Ling Zhou
The centrifugal pumps usually show the phenomenon of vibration and noise when operating under an unstable condition (Al-Obaidi & Towsyfyan, 2019). The vibration is often related to the imbalance of force. The unsteady simulations were carried out with different cavitation conditions in this section. The force in x axis and y axis directions on impeller’s blades, front and rear covers were monitored, and the results of numerical calculation are revised by dimensionless processing with the following equation (Eq.19). Where F is the combined module of the radial force vector received by the impeller; ρ is the medium density, the unit is kg/m3; u2 is the circumferential velocity at the impeller outlet, unit is m/s; b2 is the width of impeller outlet edge, unit is m.
Unknown Resistive Torque Estimation of a Rotary Drilling System Based on Kalman Filter
Published in IETE Journal of Research, 2022
R. Riane, M. Kidouche, R. Illoul, M. Z. Doghmane
During drilling operations, violent vibrations may occur in the drill string. These undesirable vibrations lead to increased fatigue of the equipment that can cause premature failure. In addition, they reduce the drilling process efficiency and damage the on-board electronic measuring tools. Several researchers agree that at present, these vibrations are the main cause of productivity loss on the rig [1]. The understanding and mastery of the drilling systems’ dynamics is an area of considerable interest in view of the significant savings and increased performance that can be achieved. Faced with this partly hazardous manipulation, it is essential to ensure more availability and reliability to these systems. The understanding of the physical phenomena governed by the drilling process requires the development of models describing their behavior. The availability of statistical tools and powerful calculators (such as RT-Lab and CompactRio) combined with models and transmission systems assume the development of control techniques and estimation strategies.