The response of layered anisotropic tubes to centrifugal loading

This paper is concerned with the experimental investigation of vibration in aircraft jet-engine rotating compressor disks of two different configurations. The blades in the first configuration were small, with relatively low mass, and had an insignificant effect on the disk vibration except for centrifugal loading. The second configuration had relatively large blades which resulted in combined blade and disk modes. The test techniques, test results, and examples of some known phenomenon as they occur in lightweight aircraft jet-engine disks are discussed.

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Rotating Disk Shape: Is the Equation Nonlinear?

Journal of Vibration and Acoustics ◽

10.1115/1.3269882 ◽

1989 ◽

Vol 111 (4) ◽

pp. 456-458

Author(s):

R. R. Jettappa

Keyword(s):

Differential Equation ◽

Linear Equation ◽

Rotating Disk ◽

Variable Coefficients ◽

Thin Disk ◽

Second Order ◽

First Order ◽

Governing Differential Equation ◽

Centrifugal Loading

The determination of the shape of a rotating disk under centrifugal loading is considered. It is shown that the governing differential equation for the shape of a rotating thin disk is reducible to a linear equation of second order with variable coefficients. However, the form of this equation is such that it can be treated as an equation of first order thereby facilitating the integration by quadratures. All this is possible without any additional mathematical assumptions so that the results are exact within the limitations of the thin disk theory.

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Naval Centrifugal Compressor Design Using CAD Solutions

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.658.59 ◽

2014 ◽

Vol 658 ◽

pp. 59-64

Author(s):

Constantin Dumitrache ◽

Ioan Calimanescu ◽

Corneliu Comandar

Keyword(s):

High Flow ◽

Mean Stress ◽

Aerodynamic Optimization ◽

Aerodynamic Forces ◽

Dynamic Stresses ◽

Unsteady Aerodynamic ◽

Wide Range ◽

Compressor Design ◽

Blade Vibrations ◽

Centrifugal Loading

Centrifugal compressors of turbochargersoperate in a wide range of rotational speeds, which depends on the load of the supercharged engine. Current designs of turbocharger compressors exhibit high efficiencies accompanied by high flow capacities [1]. Consequences of aerodynamic optimization are high mean stress values in the blades due to centrifugal loading as well as dynamic stresses due to blade vibrations. Blade vibrations in a turbocharger compressor are assumed to be predominantly excited by unsteady aerodynamic forces [2]. These forces are caused by a variety of sources influencing the flow. Examples include the geometry of the flow channel, elbows, the diffuser vanes or struts. Therefore, an understanding of FSI is essential for further design optimizations.

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Contouring the Tire Sidewall with Moire

Tire Science and Technology ◽

10.2346/1.2167174 ◽

1974 ◽

Vol 2 (1) ◽

pp. 18-39 ◽

Cited By ~ 1

Author(s):

A. L. Browne

Keyword(s):

Experimental Method ◽

Centrifugal Force ◽

Static Loading ◽

High Speed ◽

Standing Waves ◽

Operating Conditions ◽

Pneumatic Tire ◽

Normal Operating ◽

Applied Forces ◽

Centrifugal Loading

Abstract Knowledge of the tire sidewall deformation is necessary for accurate modeling of the response of a pneumatic tire to applied forces. An experimental method, the moire fringe technique, is described which permits the contouring of the tire surface under all normal operating conditions. Results are presented for a series of tests which were conducted to determine the tire sidewall deformation due to static loading, centrifugal force, combined vertical and centrifugal loading, and high speed operation (during which standing waves are present in the tire sidewall).

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Numerical Analyses of Turning-Induced and Mapped Ti6Al4V Residual Stresses for a Disc Subjected to Centrifugal Loading

International Journal of Automation Technology ◽

10.20965/ijat.2011.p0326 ◽

2011 ◽

Vol 5 (3) ◽

pp. 326-333 ◽

Cited By ~ 2

Author(s):

Shukri Afazov ◽

◽

Svetan Ratchev ◽

Adib Becker ◽

Shulong Liu ◽

...

Keyword(s):

Residual Stresses ◽

Orthogonal Cutting ◽

Numerical Analyses ◽

Hole Drilling ◽

Depth Of Cut ◽

Fe Model ◽

X Ray Diffraction ◽

Centrifugal Load ◽

Centrifugal Loading ◽

Mapping Techniques

The paper investigates the effects of turning-induced and mapped Residual Stresses (RSs) for a Ti6Al4V disc subjected to centrifugal loading. The turninginduced RSs are predicted in orthogonal cutting using the Finite Element Method (FEM). The FE predicted RSs are validated after performing face turning followed by hole drilling and x-ray diffraction measurements. Numerical analyses are carried out at different Cutting Velocities (CVs) to obtain the RS profiles. The results show that the compressive RSs increase by increasing the CV and the depth of cut. A disc subjected to a centrifugal load is modelled using the FEM where the turning-induced RSs are introduced as an initial condition using mapping techniques. The predicted CV-dependent RS profiles are incorporated into the mapping techniques using the shape function approach. It is observed that the stress amplitudes at the points at which failure occurs are lower when the mapped turning-induced RS profiles are considered in the disc FE model. The lower stress amplitudes are related to prolonging the disc life due to fatigue.

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Examination of the Effect of the Combined Use of Nd: YAG Laser Irradiation and Mechanical Force Loading on Bone Metabolism Using Cultured Human Osteoblasts

Journal of lasers in medical sciences ◽

10.34172/jlms.2020.24 ◽

2020 ◽

Vol 11 (2) ◽

pp. 138-143 ◽

Cited By ~ 1

Author(s):

Yuji Tsuka ◽

Ryo Kunimatsu ◽

Hidemi Gunji ◽

Takaharu Abe ◽

Cynthia Concepción Medina ◽

...

Keyword(s):

Bone Metabolism ◽

Laser Irradiation ◽

Mechanical Stimulation ◽

Near Infrared ◽

Yttrium Aluminum Garnet ◽

Tooth Movement ◽

Control Group ◽

Yag Laser ◽

Force Loading ◽

Centrifugal Loading

Introduction: In recent years, laser irradiation in the near-infrared ray (NIR) area has been reported to promote bone healing. There are also reports that laser irradiation accelerates orthodontic tooth movement. In this study, we investigated the effect of NIR laser irradiation and mechanical stimulation on osteoblasts. Methods: We seeded osteoblast-like cells and laser irradiation was performed 24 hours after cell seeding. In addition, a control group not receiving anything, a group receiving only Nd: YAG (neodymium-doped yttrium aluminum garnet) laser irradiation, a group receiving only centrifugal loading, and a group receiving both Nd: YAG laser irradiation and centrifugal force loading were set, and after 24 hours and after 48 hours, cells were collected and quantitative real-time polymerase chain reaction (PCR) was performed. Results: 24 hours after laser irradiation, the gene expression of alkaline phosphatase (ALP), the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) was significantly higher in the 2.0 W group than in the control group. In addition, the RANKL/OPG ratio was higher in the 2.0 W group than in the control group. Also, in the group using laser irradiation and centrifugal loading in combination, 24 hours after laser irradiation, ALP and OPG showed significantly higher values than those in the centrifugal load only group. Furthermore, the RANKL/OPG ratio also showed high values. Conclusion: These results suggest that osteoblast-like cells activate genes related to bone metabolism by combining mechanical stimulation and laser irradiation. This helps to elucidate the influence of laser irradiation during tooth movement.

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