Relevant bibliographies by topics / Gases Acoustic properties

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers

Academic literature on the topic 'Gases Acoustic properties'

Author: Grafiati
Published: 4 June 2021
Last updated: 14 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Gases Acoustic properties.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Gases Acoustic properties"

1

Molevich, Nonna E., Anatoly I. Klimov, and Vladimir G. Makaryan. "Influence of Thermodynamic Nonequilibrium on the Acoustic Properties of Gases." International Journal of Aeroacoustics 4, no. 3 (July 2005): 373–83. http://dx.doi.org/10.1260/1475472054771411.

Full text
Abstract:
This paper is a brief review of results of experimental and theoretical studies in the field of acoustics of nonequilibrium gas-plasma media. New acoustical properties of nonequilibrium media caused by the change in sign of the second viscosity and the dispersion coefficients are considered. Such media are acoustically active. Conditions are discussed for generating new nonlinear acoustical structures.
APA, Harvard, Vancouver, ISO, and other styles
2

Gillis, Keith A., James B. Mehl, and Michael R. Moldover. "Acoustic methods for transport properties measurements in gases." Journal of the Acoustical Society of America 103, no. 5 (May 1998): 2765–66. http://dx.doi.org/10.1121/1.421436.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Alferez, Nicolas, and Emile Touber. "One-dimensional refraction properties of compression shocks in non-ideal gases." Journal of Fluid Mechanics 814 (February 2, 2017): 185–221. http://dx.doi.org/10.1017/jfm.2017.10.

Full text
Abstract:
Non-ideal gases refer to deformable substances in which the speed of sound can decrease following an isentropic compression. This may occur near a phase transition such as the liquid–vapour critical point due to long-range molecular interactions. Isentropes can then become locally concave in the pressure/specific-volume phase diagram (e.g. Bethe–Zel’dovich–Thompson (BZT) gases). Following the pioneering work of Bethe (Tech. Rep. 545, Office of Scientific Research and Development, 1942) on shocks in non-ideal gases, this paper explores the refraction properties of stable compression shocks in non-reacting but arbitrary substances featuring a positive isobaric volume expansivity. A small-perturbation analysis is carried out to obtain analytical expressions for the thermo-acoustic properties of the refracted field normal to the shock front. Three new regimes are discovered: (i) an extensive but selective (in upstream Mach numbers) amplification of the entropy mode (hundreds of times larger than those of a corresponding ideal gas); (ii) discontinuous (in upstream Mach numbers) refraction properties following the appearance of non-admissible portions of the shock adiabats; (iii) the emergence of a phase shift for the generated acoustic modes and therefore the existence of conditions for which the perturbed shock does not produce any acoustic field (i.e. ‘quiet’ shocks, to contrast with the spontaneous D’yakov–Kontorovich acoustic emission expected in 2D or 3D). In the context of multidimensional flows, and compressible turbulence in particular, these results demonstrate a variety of pathways by which a supplied amount of energy (in the form of an entropy, vortical or acoustic mode) can be redistributed in the form of other entropy, acoustic and vortical modes in a manner that is simply not achievable in ideal gases. These findings are relevant for turbines and compressors operating close to the liquid–vapour critical point (e.g. organic Rankine cycle expanders, supercritical $\text{CO}_{2}$ compressors), astrophysical flows modelled as continuum media with exotic equations of state (e.g. the early Universe) or Bose–Einstein condensates with small but finite temperature effects.
APA, Harvard, Vancouver, ISO, and other styles
4

Kozlov, Vitaly F., Alexander V. Fedorov, and Norman D. Malmuth. "Acoustic properties of rarefied gases inside pores of simple geometries." Journal of the Acoustical Society of America 117, no. 6 (June 2005): 3402–11. http://dx.doi.org/10.1121/1.1893428.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Gawdzińska, K., L. Chybowski, and W. Przetakiewicz. "Study of Thermal Properties of Cast Metal- Ceramic Composite Foams." Archives of Foundry Engineering 17, no. 4 (December 20, 2017): 47–50. http://dx.doi.org/10.1515/afe-2017-0129.

Full text
Abstract:
Abstract Owing to its properties, metallic foams can be used as insulation material. Thermal properties of cast metal-ceramic composite foams have applications in transport vehicles and can act as fire resistant and acoustic insulators of bulkheads. This paper presents basic thermal properties of cast and foamed aluminum, the values of thermal conductivity coefficient of selected gases used in foaming composites and thermal capabilities of composite foams (AlSi11/SiC). A certificate of non-combustibility test of cast aluminum-ceramic foam for marine applications was included inside the paper. The composite foam was prepared by the gas injection method, consisting in direct injection of gas into liquid metal. Foams with closed and open cells were examined. The foams were foaming with foaming gas consisting of nitrogen or air. This work is one of elements of researches connected with description of properties of composite foams. In author's other works acoustic properties of these materials will be presented.
APA, Harvard, Vancouver, ISO, and other styles
6

Li, D. M., F. Pan, X. B. Wang, J. B. Niu, and M. Liu. "Microstructure and Electronic Properties of Al/Zr/LiNbO3 Multilayers." Materials Science Forum 475-479 (January 2005): 3775–78. http://dx.doi.org/10.4028/www.scientific.net/msf.475-479.3775.

Full text
Abstract:
To obtain both high power durability and fine-dimensional control in high-frequency surface acoustic wave devices, a highly oriented (111) texture was developed in electronic beam evaporated Al films on Zr underlayer. In this paper, the effects of Zr underlayer on the microstructure and resistivity of Al/Zr/LiNbO3 films were investigated. The films show an extremely smooth surface. The optimum annealing temperature is 200 °C to obtain low resistivity. For Al films with Zr underlayer, reactive ion etching with gases containing BCl3 can be more easily performed than that for Al films with Cu underlayer.
APA, Harvard, Vancouver, ISO, and other styles
7

Moldover, Michael R. "Acoustic resonators for measuring the thermodynamic and transport properties of industrial gases and for calibrating thermometers." Journal of the Acoustical Society of America 110, no. 5 (November 2001): 2627. http://dx.doi.org/10.1121/1.4776868.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Kryshtal, R. G., A. P. Kundin, A. V. Medved, and V. V. Shemet. "Surface acoustic wave gas sensor of the sorption type sensitive to the thermal properties of gases." Technical Physics Letters 28, no. 1 (January 2002): 50–51. http://dx.doi.org/10.1134/1.1448641.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Seidel, Günter, Klaus-Dieter Beller, Rune Aaslid, Rolf-Peter Hummel, Ulrich Thibaut, Marion Vidal-Langwasser, Bernd Kukat, and Manfred Kaps. "The Influence of Different Gases on Acoustic Properties of a Spherosome-Based Ultrasound Contrast Agent (BY963)." Journal of Neuroimaging 8, no. 2 (April 1998): 83–87. http://dx.doi.org/10.1111/jon19988283.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Vasilyev, Andrey. "AUTOMOBILE INTERNAL COMBUSTION ENGINE PRESSURE CHARGING AND GAS-GUIDE LOW FREQUENCY NOISE REDUCTION USING ACTIVE SOUND SOURCES." Akustika 34 (November 1, 2019): 118–22. http://dx.doi.org/10.36336/akustika201934118.

Full text
Abstract:
Pressure charging devices in different types of internal combustion engines is allowing to achieve a number of advantages: engine power and fuel effectiveness increasing, exhaust gases toxic reduction etc. Pressure charging systems may be classified by the different parameters. For the time being turbo-supercharger is the most popular unit of serial automobile engines pressure charging. But it has some negative properties. Therefore using of dynamic (acoustic) pressure charging devices is promising solution. Analysis of existing acoustic pressure charging systems is carried out. The perspectives of using of active sound emitters for acoustic pressure charging are described. Theoretical issues of automobile engines active acoustic charging are discussed. Construction of active charging system is suggested. Multifunctional approach to automobile internal combustion engines pressure charging and low frequency intake and exhaust noise reduction is suggested. The results described in this paper may be useful for further development and application of internal combustion engines with improved consumer’s and ecological characteristic.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Gases Acoustic properties"

1

Cottet, Aurelien. "Acoustic absorption measurements for characterisation of gas mixing." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/12428.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Buxton, Amanda Jane. "The thermophysical properties of gases determined using an annular acoustic resonator." Thesis, University College London (University of London), 1997. http://discovery.ucl.ac.uk/1317666/.

Full text
Abstract:
A novel annular acoustic resonator was constructed for measurements of the speed of sound in gases at pressures below 1 MPa. The resonator was designed to allow measurements of the speed and absorption of sound at low pressure in gases with large bulk viscosities. Measurements in propene, for which the speed of sound is known, served to characterise the geometry of the resonator and provide a test of the acoustic model for the system. A detailed description of the resonator which has an outer radius of 140 mm is given. The large radius provides low frequency resonance modes that minimise acoustic losses in the bulk of the gas. Three substances were studied: trifluoromethane, sulfur hexafluoride and a binary mixture consisting of methane and ethane with mole fraction composition {0.85 CH₄ + 0.15 C₂H₆}. Measurements were conducted over the temperature range 230 to 350 K, and the results analysed to obtain perfect gas heat capacities and second acoustic virial coefficients. The heat capacity data are compared to literature sources. Values for the second (p,V,T) virial coefficients were obtained from the second acoustic virial coefficients and the results are compared with previous determinations. Analysis of the acoustic loss mechanisms allows the shear viscosity, thermal conductivity and bulk viscosity of the gas to be estimated. The values obtained do not have the accuracy that may be achieved using specialised techniques and a comparison is made where data is available. The estimates of the thermal conductivity and shear and bulk viscosities provide a new self consistent method for the analysis of the acoustic results which does not rely on literature values for the transport coefficients. Where possible vibrational relaxation times are evaluated from the bulk viscosity and are compared with results from other sources.
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Gases Acoustic properties"

1

Škvor, Zdeněk. Obvodové modely kmitajících soustav v pevné a plynné fázi. Praha: Academia, nakl. Československé akademie věd, 1986.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Bakhvalov, N. S. Nonlinear theory of sound beams. New York: American Institute of Physics, 1987.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Unger, Bruce T. Optically stimulated sound from gas bubbles in water. 1987.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

[Flight and static exhaust flow properties of an F110-GE-129 engine in an F-16XL airplane during acoustic tests]. [Edwards, Calif: NASA Dryden Flight Research Center, 1996.

Find full text
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Gases Acoustic properties"

1

Moldover, M. R., K. A. Gillis, J. J. Hurly, J. B. Mehl, and J. Wilhelm. "Acoustic Measurements in Gases." In Handbook of Elastic Properties of Solids, Liquids, and Gases, 329–70. Elsevier, 2001. http://dx.doi.org/10.1016/b978-012445760-7/50082-4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Moldover, M. R., K. A. Gillis, J. J. Hurly, J. B. Mehl, and J. Wilhelm. "10. Acoustic measurements in gases." In Modern Acoustical Techniques for the Measurennent of Mechanical Properties, 377–427. Elsevier, 2001. http://dx.doi.org/10.1016/s1079-4042(01)80093-x.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Prasad, Manika, Amos Nur, Gary Mavko, and Jack Dvorkin. "Acoustic Properties in Petroliferous Liquids." In Handbook of Elastic Properties of Solids, Liquids, and Gases, 207–18. Elsevier, 2001. http://dx.doi.org/10.1016/b978-012445760-7/50078-2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Maynard, J. D. "Acoustic Properties of Superfluid Helium Four." In Handbook of Elastic Properties of Solids, Liquids, and Gases, 147–57. Elsevier, 2001. http://dx.doi.org/10.1016/b978-012445760-7/50075-7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Prosperetti, Andrea. "Fundamental Acoustic Properties of Bubbly Liquids." In Handbook of Elastic Properties of Solids, Liquids, and Gases, 183–205. Elsevier, 2001. http://dx.doi.org/10.1016/b978-012445760-7/50077-0.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Lomonosov, Alexey, Andreas P. Mayer, and Peter Hess. "Laser Controlled Surface Acoustic Waves." In Handbook of Elastic Properties of Solids, Liquids, and Gases, 137–86. Elsevier, 2001. http://dx.doi.org/10.1016/b978-012445760-7/50009-5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Zinin, Pavel V. "Quantitative Acoustic Microscopy of Solids." In Handbook of Elastic Properties of Solids, Liquids, and Gases, 187–226. Elsevier, 2001. http://dx.doi.org/10.1016/b978-012445760-7/50010-1.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Prasad, Manika, Amos Nur, Gary Mavko, and Jack Dvorkin. "Acoustic Properties in Rocks Saturated with Petroliferous Liquids." In Handbook of Elastic Properties of Solids, Liquids, and Gases, 219–31. Elsevier, 2001. http://dx.doi.org/10.1016/b978-012445760-7/50079-4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Zolotoyabko, Emil. "X-Ray Diffraction and Scattering on Acoustic Phonons." In Handbook of Elastic Properties of Solids, Liquids, and Gases, 419–38. Elsevier, 2001. http://dx.doi.org/10.1016/b978-012445760-7/50020-4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Giacobhe, F. W. "Use of Cyclindrical Acoustic Resonance to Measure the Speed of Sound in Gases." In Handbook of Elastic Properties of Solids, Liquids, and Gases, 371–87. Elsevier, 2001. http://dx.doi.org/10.1016/b978-012445760-7/50083-6.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Gases Acoustic properties"

1

Hurly, John J. "Properties of process gases determined accurately with acoustic techniques." In CHARACTERIZATION AND METROLOGY FOR ULSI TECHNOLOGY. ASCE, 1998. http://dx.doi.org/10.1063/1.56888.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Shams, A., C. Macbeth, and F. Gozalpour. "Determination of the Acoustic Properties of Hydrocarbon Rich Gases Using PVT Relations." In 69th EAGE Conference and Exhibition incorporating SPE EUROPEC 2007. European Association of Geoscientists & Engineers, 2007. http://dx.doi.org/10.3997/2214-4609.201401728.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

McPherson, Patrick, Elizabeth Cadogan, and Al Ferri. "Improvement of Convergence Properties for Ritz Formulations of Acousto-Elasticity Problems." In ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/detc2012-71137.

Full text
Abstract:
Many applications require the analysis of structures with cavities filled with fluids or gases. In many cases the fluid domains can be ignored, and we can safely assume that the structure’s in vacuo properties apply. Sometimes, however, resonances in the fluid can couple with structural resonances to yield acousto-elastic modes of response. The most popular approach to these problems is to describe the trapped fluid in terms of a finite number of eigenmodes of a geometrically identical cavity with rigid boundaries. Then, the structural and fluid domains are coupled by matching the pressure across the wetted surface. However, for light structures with embedded cavities of relatively heavy fluids such as water, this technique may not be satisfactory because the interior rigid-cavity modes are poor candidates to satisfy the “natural boundary conditions” that exist at the fluid-structure boundary. This paper explores the use of an expanded set of Ritz functions for the fluid domain, to include a number of functions that explicitly allow for motion along the wetted surface. The method is applied to a two-dimensional rectangular acoustic cavity, with rigid boundaries on all sides except for a flexible membrane on the top surface. Through comparisons with the “exact solution,” it is shown that the solution using the expanded set of Ritz functions converges more quickly than do solutions employing rigid cavity modes. The convergence trends of the first few natural frequencies are computed for a number of different physical and geometric system properties.
APA, Harvard, Vancouver, ISO, and other styles
4

Mazur, Marek, Wenjie Tao, Philippe Scouflaire, Franck Richecoeur, and Sébastien Ducruix. "Experimental and Analytical Study of the Acoustic Properties of a Gas Turbine Model Combustor With a Choked Nozzle." In ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gt2015-43013.

Full text
Abstract:
Combustion is now considered as a non-negligible contributor to gas turbine noise. Combustion noise can be divided into two types: direct combustion noise directly caused by flame surface fluctuations and indirect combustion noise caused by non-homogeneities in the burnt gases, which radiate sound when interacting with the first turbine stages. The aim of the present project is to obtain an extensive experimental database as well as a better understanding of the physical phenomena inside a pressurized combustion chamber with a choked exhaust nozzle. To do so, a pressurized model scale combustor has been developed, containing a tangential admission injector creating a swirling premixed flow. Satisfactory premixing is obtained in the injection device by a porous media. The combustion chamber shows large optical accesses and various ports for pressure and temperature sensors. On the upstream side, an impedance control device is installed while, downstream, the exhaust nozzle can be easily varied to study its influence on noise generation. A mean chamber pressure higher than 2 bar can be reached for the targeted operating points. The present analysis of the flame behaviour is a first step towards the study of combustion noise. The flame dynamics are characterized by spectral analysis of the dynamic pressure in the combustion chamber. The aim of this work is to determine the dominating acoustic modes during combustion operation. With the help of analytical calculations, the test bench is first modelled as a two cavity system, and later as a five cavity system, taking into account the feeding lines. The nozzle can be assumed as choked due to the pressurization of the chamber. With this method, the majority of the acoustic modes can be identified and explained. The study shows that these modes are linked to the geometry of the whole combustor including the injection tube, the combustion chamber and the feeding lines.
APA, Harvard, Vancouver, ISO, and other styles
5

Ajetunmobi, Oluwaseun, Midhat Talibi, and Ramanarayanan Balachandran. "Dynamic Response of Acoustically Forced Turbulent Premixed Biogas Flames." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-91379.

Full text
Abstract:
Abstract Increasing demand for energy and the need for diversification of fuels used in gas turbine power generation is continuing to drive forward the development of fuel-flexible combustion systems, with particular focus on biomass derived sustainable fuels. The technical challenges arising from burning sustainable fuels are largely associated with the change in the chemical, thermal and transport properties of these fuels due to the variation of the constituents and their impact on the performance of the combustor including emissions, static and dynamic stabilities. There is a lack of detailed understanding on the effect of fuel composition on the flame sensitivity to acoustic and flow perturbations. This paper describes an experimental study investigating the acoustic flame response of simulated biogas (methane/carbon dioxide/air mixtures) turbulent premixed flames. The effect of variation in carbondioxide, CO2, content on the flame response was quantified. Special emphasis was placed on understanding the dependence of this flame response on the amplitude of the acoustic forcing. The flame was subjected to strong velocity perturbations using loud speakers. It was observed that the addition of CO2 had considerable influence on the magnitude of heat release response. The magnitude and the phase of flame describing function indicated that the mechanism of saturation in these flames for all conditions tested were the same. The difference in magnitude could been attributed to dilution effect and hence further investigation were carried out with N2 and Ar to clarify the role of CO2. The results indicate that the thermal capacity of the diluent gases could be playing a significant role in nonlinear flame dynamics.
APA, Harvard, Vancouver, ISO, and other styles
6

Swinteck, N., S. Bringuier, and P. A. Deymier. "Phononic Crystals With Full Phase-Space Properties: Application to Boolean Logic Gates." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-62964.

Full text
Abstract:
Based on a phononic crystal (PC) constituted of a square array of cylindrical Polyvinylchloride inclusions in air, a theoretical model is constructed that details three schemes for controlling the relative phase between propagating acoustic waves in this PC. In exploiting the spectral, wave vector and wave-phase properties of this PC, a series of acoustic based Boolean logic gates are constructed. Finite-difference time-domain simulations are employed to validate theoretical models and demonstrate the NAND, XOR and NOT Boolean logic gates.
APA, Harvard, Vancouver, ISO, and other styles
7

Fusi, Andrea, Leonardo Cappelli, Cosimo Carcasci, and Marco Sacco. "Tuning of the Acoustical Analysis Model for Hypercompressors Through Strain Gage Pulsation Measurements." In ASME 2019 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/pvp2019-93077.

Full text
Abstract:
Abstract Reciprocating compressor plants are typically exposed to vibrations, resulting from the discontinuity of the flow (pressure pulsations) and from external mechanical loads (compressor motion). To minimize the impact of pressure pulsations on vibration issues, a robust acoustical study is needed in the early design stage. Reliable standards and guidelines concerning vibration and pulsation are available for common applications (up to 350 bar) [1][2]. Within this pressure range it is possible to meet the standards by introducing pulsation suppression devices such as volume bottles or orifices. The Low-Density Polyethylene (LDPE) process requires very high pressures obtained with dedicated machines (Hypercompressors). There are no specific pulsation guidelines for these extreme pressures; in addiction reactive pulsation suppression devices like volume bottles are ineffective due to the high speed of sound in real gas (and related long wavelengths) at such pressures. This paper describes the case history of a plant which exhibited high piping vibration from the first machine start-up. A survey was made to measure vibrations and pressure pulsations by means of strain gages: internal pressure was derived from external deformation through pressure vessel theory. Strain gages were chosen because they can be easily installed without positioning restrictions, while dynamic pressure sensors require pressure taps and must be limited to specific points. Pulsation measurements were compared with an acoustic analysis, showing some discrepancy, especially at relatively high harmonics, mainly due to incorrect evaluation of the thermodynamic properties of high-pressure ethylene. In fact, in the LDPE process pressure range, isentropic exponent kv and compressibility factor Z can reach very high values, consequently affecting the calculation of the speed of sound. A new acoustic modelling was developed to achieve better consistency with the measurements. Pressure-dependent kv and Z were taken into account and a sensitivity analysis of the most relevant valve parameters was performed. Comparing the vibrations and pulsations spectra, once the MNF, compressor manifold arrangement and external loads are known, is fundamental to detect the origin of vibrations and how they are affected by pulsations.
APA, Harvard, Vancouver, ISO, and other styles
8

Hertlein, Nathan, David Yoo, Philip R. Buskohl, Kumar Vemaganti, and Sam Anand. "Bayesian Optimization of Target Buckling Shapes in Constrained Elastomeric Beams With Geometric Uncertainty." In ASME 2020 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/detc2020-22608.

Full text
Abstract:
Abstract Additive manufacturing has enabled the fabrication of complex, architected materials, which have shown great promise in fields such as acoustics, mechanical logic gates, and energy trapping, due to their unique properties derived from repeating unit cells. The force-displacement performance of one such unit cell, the bistable elastomeric beam, has been characterized experimentally and subsequently tuned by the introduction of a Fourier series-based design parameterization that enables a wider range of available energy performance characteristics and secondary stable configurations. Here, another characteristic of this beam that has not yet been explored, namely the shape during post-buckling deformation between the two stable states, is optimized under the same Fourier series-based parameterization. Nonlinear finite element analysis reveals that the performance is highly sensitive to even modest profile error incurred on the beam’s upper and lower sides during manufacturing. Various methods of quantifying performance are compared, and Bayesian optimization is employed in two case studies to achieve desired post-buckled shapes. A novel acquisition function, which considers a candidate design’s robustness to profile error, is used to find the design that achieves the desired performance consistently, even in the face of the variability associated with additive manufacturing. Finally, Monte Carlo simulations are used to quantify the performance of optimal beams found with and without the new acquisition function, and reveal the importance of considering geometric uncertainty during the optimization process.
APA, Harvard, Vancouver, ISO, and other styles
9

Untaroiu, Costin D., Robert S. Salzar, Herve´ Guillemot, and Jeff R. Crandall. "The Strain Distribution and Force Transmission Path Through Pubic Rami During Lateral Pelvic Impacts." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-67791.

Full text
Abstract:
The pubic rami fracture is a common pelvic injury for vehicle occupants as well as for pedestrians struck during side impacts. While many studies have investigated the structural properties of the pelvis in lateral loading, relatively few investigations have compared the applied loads with local response of the pubic rami. The aims of this study are to investigate the force transmission paths and strain distribution for the anterior (i.e., rami) and posterior (i.e., sacrum) regions of the pelvis under acetabular impact loading. Eight male postmortem human surrogate pelves were tested to failure in quasi-static (n = 2) and dynamic (n = 6) conditions using an Instron test machine and a drop-tower, respectively. The denuded pelves were potted and then cut along a line connecting the greater sciatic notch and the middle of anterior iliac spine. Lateral loading was applied at the site of the acetabulum using a custom-fit femoral head surrogate made of steel. An acoustic emission (AE) sensor and uniaxial strain gages were affixed to the four rami (anterior and posterior) to assess the time of fracture as well as the regional strain distribution. In addition to measuring the impacting force, the loads transmitted through the pelvis were recorded on the non-struck side using load cells at the inferior and superior potting attachment points. To better understand the load path and strain distribution through the rami a finite element model of a human pelvis was developed from computer tomography data and validated based on available published test data. Then, the lateral impact test was numerically simulated and the model responses were mostly within the min-max ranges of the test data. The test data and FE simulations showed that prior to the fracture the pubic symphysis joint transmitted the higher percentage of load (about 66% in dynamic tests). The strain distribution analysis of the impact pelvic tests showed that the pubic rami are subjected predominantly to compressive stress on the anterior side and tensile stress on the posterior side. While the anterior pubic side of the non-impact part of the pelvis was always subjected to compressive stress, some test variability was observed on other regions of the non-impact sides. In addition to providing validation data for computational models, the results highlight the vulnerability of pubic rami structure in carrying lateral load in acetabular impacts and may lend insight into the development of injury countermeasures.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Gases Acoustic properties' for particular source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography