Experimental studies of the effects of buffered particle dampers attached to a multi-degree-of-freedom system under dynamic loads

2012 ◽  
Vol 331 (9) ◽  
pp. 2007-2022 ◽  
Author(s):  
Zheng Lu ◽  
Xilin Lu ◽  
Wensheng Lu ◽  
Sami F. Masri
Keyword(s):  
Experimental Studies ◽  
Degree Of Freedom ◽  
Dynamic Loads ◽  
Particle Dampers

scholarly journals Particle Damping with Granular Materials for Multi Degree of Freedom System

2011 ◽  
Vol 18 (1-2) ◽  
pp. 245-256 ◽  
Author(s):  
Masanobu Inoue ◽  
Isao Yokomichi ◽  
Koju Hiraki
Keyword(s):  
Granular Materials ◽  
Equations Of Motion ◽  
Experimental Studies ◽  
Wide Frequency Range ◽  
Vertical Vibration ◽  
Degree Of Freedom ◽  
Particle Damping ◽  
Single Mass ◽  
Particle Dampers ◽  
Particle Bed

A particle damper consists of a bed of granular materials moving in cavities within a multi degree-of-freedom (MDOF) structure. This paper deals with the damping effects on forced vibrations of a MDOF structure provided with the vertical particle dampers. In the analysis, the particle bed is assumed to be a single mass, and the collisions between the granules and the cavities are completely inelastic, i.e., all energy dissipation mechanisms are wrapped into zero coefficient of restitution. To predict the particle damping effect, equations of motion are developed in terms of equivalent single degree-of-freedom (SDOF) system and damper mass with use made of modal approach. In this report, the periodic vibration model comprising sustained contact on or separation of the damper mass from vibrating structure is developed. A digital model is also formulated to simulate the damped motion of the physical system, taking account of all vibration modes. Numerical and experimental studies are made of the damping performance of plural dampers located at selected positions throughout a 3MDOF system. The experimental results confirm numerical prediction that collision between granules and structures is completely inelastic as the contributing mechanism of damping in the vertical vibration. It is found that particle dampers with properly selected mass ratios and clearances effectively suppress the resonance peaks over a wide frequency range.

scholarly journals Effect of dynamic loads and vibrations on lithium-ion batteries

2021 ◽  
pp. 146134842110081
Author(s):  
Xia Hua ◽  
Alan Thomas
Keyword(s):  
Lithium Ion Batteries ◽  
Lithium Ion Battery ◽  
Experimental Studies ◽  
Lithium Ion ◽  
Battery Pack ◽  
Dynamic Loads ◽  
Electrical Performance ◽  
Mechanical Degradation ◽  
Energy Storage Devices ◽  
Battery Cell

Lithium-ion batteries are being increasingly used as the main energy storage devices in modern mobile applications, including modern spacecrafts, satellites, and electric vehicles, in which consistent and severe vibrations exist. As the lithium-ion battery market share grows, so must our understanding of the effect of mechanical vibrations and shocks on the electrical performance and mechanical properties of such batteries. Only a few recent studies investigated the effect of vibrations on the degradation and fatigue of battery cell materials as well as the effect of vibrations on the battery pack structure. This review focused on the recent progress in determining the effect of dynamic loads and vibrations on lithium-ion batteries to advance the understanding of lithium-ion battery systems. Theoretical, computational, and experimental studies conducted in both academia and industry in the past few years are reviewed herein. Although the effect of dynamic loads and random vibrations on the mechanical behavior of battery pack structures has been investigated and the correlation between vibration and the battery cell electrical performance has been determined to support the development of more robust electrical systems, it is still necessary to clarify the mechanical degradation mechanisms that affect the electrical performance and safety of battery cells.

On the question of the appointment of separate parameters of the roadheaders gathering-stars loading organs

2021 ◽  
pp. 90-93
Author(s):  
N.B. Afonina ◽  
A.V. Otrokov ◽  
G.Sh. Khazanovich
Keyword(s):  
Energy Consumption ◽  
Experimental Studies ◽  
The Other ◽  
Dynamic Loads ◽  
Selective Action ◽  
Side Edge ◽  
Fluidized State ◽  
High Dynamic ◽  
Loading Devices

Most modern roadheaders of selective action are equipped with loading devices with gathering-stars, which have a simpler drive design and increased reliability. As a result of the experimental studies carried out at SRSPU (NPI), it was found that under certain conditions, it is possible to transfer large lump material of a pile into a fluidized state, which reduces the energy consumption of material loading. An increase in the number of beams of the gathering-stars reduces the influence of the other parameters of the loader. Analysis of the process of interaction of the gathering-star’s beam with the receiving conveyor’s side edge to avoid jamming of the picking gathering-star by a lump of material with the implementation of high dynamic loads, it is necessary to set the gathering-beams at an angle of at least 60 degrees against rotation.

Experimental studies of the effect of concentrated dynamic loads on a three-layer structure with a filler

2021 ◽  
pp. 20-21
Author(s):  
Keyword(s):  
Comparative Analysis ◽  
Glass Fiber ◽  
Impact Loading ◽  
Layer Structure ◽  
Experimental Studies ◽  
Theoretical Data ◽  
Dynamic Loads ◽  
Bearing Layer

The results of experimental studies of the effect of concentrated dynamic loads on a three-layer structure with glass fiber filler are presented. A comparative analysis of the obtained results with theoretical data is carried out. Keywords: three-layer structure, striker, bearing layer, fiberglass, impact loading. [email protected]

scholarly journals Review of studies on plugging compositions creation with controlled rheological properties and the ability to restore fluidity for completion, workover and abandonment of oil and gas wells

2021 ◽  
pp. 28-46
Author(s):  
D. S. Klimov ◽  
◽  
S. S. Ostapchuk ◽  
E. S. Zakirov ◽  
◽  
...  
Keyword(s):  
Oil And Gas ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Dynamic Loads ◽  
Cement Stone ◽  
Self Healing ◽  
Gas Wells ◽  
Oil And Gas Wells ◽  
Influence Of Temperature On ◽  
Zonal Isolation

The main purpose of cementing oil and gas wells is zonal isolation of the formations exposed by the wellbore. During the entire life of the well, there should be no uncontrolled hydraulic communication between the developed formations and the surface, regardless of the composition and type of fluid (water, oil or gas). During the operation of the well, in addition to constant static ones, the casing and cement stone also experience various dynamic loads. The article presents an up-to-date review of experimental studies on the modification of grouting compositions and cement composites capable of autonomous selfhealing due to the introduction of various additives and nanomaterials. Such modification technologies significantly increase the tightness and resistance of cement to the effects of dynamic loads, the integrity of the cement stone. As a replacement for traditional cement materials, the authors propose the creation of grouting compositions with controlled physical and mechanical properties and the possibility of their re-liquefaction under the influence of temperature on the basis of bitumen or bitumen composites. Keywords: well plugging and abandoning; self-healing materials; autonomous self-healing; casing durability; impermeability of the cement stone; self-healing cement; bitumen and bitumen composites.

scholarly journals Experimental studies of ride quality of selfpropelled combine harvester

2018 ◽  
Vol 226 ◽  
pp. 01003
Author(s):  
Pavel V. Sirotin ◽  
Aleksandr G. Sapegin ◽  
Sergey V. Zlenko
Keyword(s):  
Experimental Studies ◽  
Statistical Processing ◽  
Quality Parameters ◽  
Operating Conditions ◽  
Dynamic Loads ◽  
Ride Quality ◽  
Movement Dynamics ◽  
Combine Harvester ◽  
Vibration Modal ◽  
The Given

The given work is devoted to the study of dynamic loads acting upon a combine harvester, which is one of the most vibration-loaded types of modern transport and technological machines. The results on the evaluation of dynamic loads and ride quality parameters of a self-propelled combine harvester when driving along gravel and bituminous surfaces under various operating conditions are presented based on complex experimental studies carried out with the help of tensor and vibrometry methods. The method and conditions of measurements are given. On the basis of the experimental studies, the acceleration spectrum on the main parts of the combine harvester are presented and their description is given. Using the methods of spectral analysis and statistical processing, a vibration modal analysis has been carried out during a combine harvester movement. According to the results of the analysis, the basic vibrational modes have been determined, and it has been shown that the self-propelled combine harvester movement dynamics is determined by vertical and longitudinal-angular vibrations of its core on pneumatic tires. Further scientific research directions to improve the ride quality and to decrease the dynamic loads on a considered class of self-propelled agricultural machines have been determined.

Strength of Normal and Inclined Sections of Bent Reinforced Concrete Elements with Zone Reinforcement Made of Steel Fiber

2022 ◽  
Vol 906 ◽  
pp. 7-15
Author(s):  
Dmitry Utkin
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Loading ◽  
Calculation Method ◽  
Steel Fiber ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Dynamic Loads ◽  
Reinforced Concrete Structures ◽  
Short Term ◽  
Concrete Elements

On the basis of theoretical and experimental studies, the prerequisites and the method of calculation of bent and compressed-curved reinforced concrete structures with zone reinforcement made of steel fiber, working under static and short-term dynamic loads, are formulated. In the developed method for calculating the strength of normal and inclined sections, a nonlinear deformation model is implemented, which is based on the actual deformation diagrams of materials. The developed calculation method is brought to the program of calculation of reinforced concrete structures with zone reinforcement of steel fiber under short-term dynamic loading, taking into account the inelastic properties of materials. The numerical studies made it possible to determine the influence of various parameters of steel-fiber reinforcement on the strength of reinforced concrete elements. To confirm the main results of the developed calculation method, experimental studies of reinforced concrete beam structures reinforced with conventional reinforcement and a zone steel-fiber layer are planned and carried out. Experimental studies were carried out under static and short-term dynamic loads. As a result of the conducted experiments, data were obtained that characterize the process of destruction, deformation and cracking of steel-reinforced concrete elements under such types of loading. The dependences of changes in the energy intensity of reinforced concrete structures with zone reinforcement made of steel fiber in the compressed and stretched cross-section zones under dynamic loading are obtained. The effectiveness of the use of fiber reinforcement of normal and inclined sections of bent and compressed-curved elements to improve the strength and deformative.

ENSURING TIGHTNESS IN PRESSURE COUPLING PARTS

2021 ◽  
Vol 2021 (11) ◽  
pp. 51-59
Author(s):  
Nikolay Kurnosov ◽  
Aleksandr Tarnopol'skiy ◽  
Yuliya Nakashidze
Keyword(s):  
Mechanical Properties ◽  
Cyclic Load ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Accelerated Testing ◽  
Dynamic Loads ◽  
Surface Material ◽  
Urgent Problem ◽  
Mating Surface ◽  
The Impact

Work objective is to solve the urgent problem of increasing the tightness and reliability of pressure couplings during their operation under dynamic loads. Theoretical and experimental studies assessing the impact on the tightness due to roughness nature of mating surfaces and three types of coatings: soft, double-layer and hard have been undertaken. The joints were tested under the influence of axial cyclic load and torque on a bench for accelerated testing. It is established that tightness of pressure couplings during operation under dynamic loads significantly depends on the parameters of microgeometry and physical and mechanical properties of the mating surface material that determine their actual contact area. Recommendations for preparing the surfaces of parts before pressure coupling assembling have been developed. It is proved that the use of regular microrelief and soft galvanic coatings of mating surfaces have a significant effect on the tightness of pressure couplings.

Sign in / Sign up

Export Citation Format

Share Document