Squeeze process under impact, in highly compressible porous layers, imbibed with liquids

Pascovici, M. D.; Cicone, Traian; Marian, V G

doi:10.1016/j.triboint.2009.05.006

Cited by 17 publications

(8 citation statements)

References 7 publications

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“…Therefore, based on the Ex-Poro-Hydrodynamic theory developed by Pascovici et al [ 18 ] in porous materials soaked with liquid under the compression, the damping force increases with indentation speed. By similarity, the finger tissue includes a lot of blood capillaries and by increasing of the indentation speed, it is normal that the damping force increases.…”

Section: Determination Of the Effective Young’s Modulus Of The Midmentioning

confidence: 99%

Sensors and Actuators on Determining Parameters for Being Considered in Selection of Elastomers for Biomimetic Hands

Cârlescu

Olaru

Prisăcaru

et al. 2017

Sensors

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In this paper, the authors present a new methodology to study the viscoelastic behaviour of the human finger. The methodology is based on experimental research consisting of a finger’s indentation with a small steel cylindrical object for various indentation speeds. The tests were realized on a CETR UMT-2 Tribometer for indentation speed between 0.02 mm/s and 4 mm/s with a normal load of up to 22 N. Using the force–deformation diagrams recorded at the smallest indentation speed determined the elastic modulus of the human finger according to an adapted Hertzian model. By considering the increasing of the indentation force with indentation speed, the viscous component of the human finger was evidenced. The power dissipated in the finger tissue as a result of the prehension process has been obtained as a function of indentation speed and indentation depth. In addition, a general equation for the prehension force as a function of indentation speed and indentation depth has been obtained. The results of this study will be relevant for selection of the specific elastomers used in biomimetic hands.

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Section: Determination Of the Effective Young’s Modulus Of The Midmentioning

confidence: 99%

Sensors and Actuators on Determining Parameters for Being Considered in Selection of Elastomers for Biomimetic Hands

Cârlescu

Olaru

Prisăcaru

et al. 2017

Sensors

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show abstract

“…Their models were developed for Newtonian fluids, and based on three assumptions: (i) the porous material is highly deformable and the forces generated by the elastic structure are negligible compared to the fluid pressure forces; (ii) the permeability varies with porosity (which in turn is variable with the level of compression) and permeability-porosity correlation is given by Kozeny-Carman law; and (iii) the porous structure does not inflate during compression and correspondingly, the area normal to the direction of compression remains constant. Applications were imagined for squeeze dampers [6,7] and shock absorbers [4].…”

Section: Introductionmentioning

confidence: 99%

Squeeze Flow of Bingham Fluids through Reticulated, Compressed Foams

2019

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The paper presents experimental and theoretical results for the planar squeeze flow of a finite volume of viscoplastic material through a highly deformable porous layer. The central zone of an annular disc made of a reticulated polyurethane foam with high porosity (ε > 0.97) was fully filled with tooth paste. The porous disc placed between two flat, impermeable, parallel, and rigid discs was subjected to compression and the normal force was recorded. After compression, the radial extension of the squeezed fluid was measured. The visualisation of the compressed disc managed to provide evidence of a tortuous flow inside the porous structure. An original analytical model is proposed for the prediction of the front of the flow inside the porous layer and corresponding resistant normal force. The model combines the Covey and Stanmore (1981) model for squeeze flow of a Bingham fluid inside the central zone, with an original approach for flow through the reticulated foams, based on the concept of "equivalent flow tubes" with variable tortuosity. This explorative investigation is of interest for innovative shock absorbers. The model validity covers both low and high plasticity numbers and was experimentally validated for low speed.

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Section: Introductionmentioning

confidence: 99%

“…Fluid flow through extremely compressible porous structures (highly compressible porous layer, HCPL) subjected to external loads is known as exporo-hydrodynamic (XPHD) lubrication [1,2]. This new mechanism of lubrication requires that the elastic compression forces of the HCPL solid phase are negligible compared to the hydrodynamic (HD) pressure forces generated within the porous layer [2]. Porous materials that can be considered as HCPL type are: the endothelial surface glycocalyx that uniformly coats the microvessels [3,4], articular cartilage [5,6], fresh powder snow [7], and unwoven and woven textile materials such as felt or washcloth [8].…”

Section: Introductionmentioning

confidence: 99%

“…The studies of squeeze processes (normal motion) considered both constant velocity motion and variable velocity motion by loading the mobile part with a constant force or by impact. Recent studies concerning the squeeze process under impact conditions in XPHD regime were performed theoretically and experimentally for the aligned plates geometries [2] and sphere-to-plane contact [10].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Squeeze processes in a narrow circular damper with highly compressible porous layer imbibed with liquids

Ilie

Pascovici

Marian

2011

Proceedings of the Institution of Mechanical Engineers, Part J:

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Squeeze film dampers are widely used technical components for turbomachinery as a means to reduce the amplitude of rotor vibration owing to unbalance. This article proposes a different type of circular damper using highly compressible porous layers (HCPL) imbibed with Newtonian liquids. The elastic forces of the HCPL solid phase are negligible compared to the hydrodynamic forces generated within the porous layer. Such processes were named ex-poro-hydrodynamic (XPHD). The Kozeny-Carman equation was used to compute permeability in function of porosity/compacticity. Analytical and numerical solutions were performed for the impact process of the partial and full narrow circular dampers in XPHD conditions. The results were compared with the case of the classical squeeze film damper. The damping capacity of a HCPL imbibed with Newtonian liquid was found to be considerably greater than that of the Newtonian liquid layer.

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Squeeze process under impact, in highly compressible porous layers, imbibed with liquids

Cited by 17 publications

References 7 publications

Sensors and Actuators on Determining Parameters for Being Considered in Selection of Elastomers for Biomimetic Hands

Sensors and Actuators on Determining Parameters for Being Considered in Selection of Elastomers for Biomimetic Hands

Squeeze Flow of Bingham Fluids through Reticulated, Compressed Foams

Squeeze processes in a narrow circular damper with highly compressible porous layer imbibed with liquids

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