scholarly journals Experimental Study of See-Saw Mode Nano-Vibration on Orifice-Type Restrictors

2021 ◽  
Vol 11 (11) ◽  
pp. 5265
Author(s):  
Xiaoyan Shen ◽  
Jing Yu ◽  
Jianlong Yin ◽  
Dongsheng Li
Keyword(s):  
High Performance ◽  
Natural Frequencies ◽  
Interaction Model ◽  
Nanometer Scale ◽  
Laser Vibrometer ◽  
Supply Pressure ◽  
Air Supply ◽  
Macro Scale ◽  
Vibration Performance ◽  
Fluid Parameters

Slide stability is key to the aerostatic guide in ultra-precise machines; thus, it has garnered plenty of attention. Macro-scale studies are commonplace, but micro- and nano-vibration issues require more attention. Microscope vibration is mainly caused by tiny changes in the fluid parameters of lubricating gas film, which is complex and has no verdict. In this case, slide-gas interaction should be considered. In this study, the widely used orifice-type restrictor was investigated for its nano-vibration performance. A Comsol finite-element-method fluid–structure interaction model was used to simulate and analyze an orifice-type restrictor, and orifice-restrictor vibration characteristics at the nanometer scale were inspected using a high-performance laser vibrometer. The results demonstrate that see-saw mode vibrations occur in the restrictors, growing stronger with increased air-supply pressure. The see-saw vibration’s axis is speculatively determined based on orifice and restrictor structures, and the vibration type is related to the number of orifices. The results also show that the vibration is random with natural frequencies at the kilohertz level. The newly provided research results are beneficial for better understanding the nano-vibrations of orifice-type restrictors.

ADDITIVE MANUFACTURING OF HIGH-LOADING POLYMER NANOCOMPOSITES WITH MULTISCALE ALIGNMENT

2021 ◽  
Author(s):  
SOYEON PARK ◽  
KUN (KELVIN) FU
Keyword(s):  
Additive Manufacturing ◽  
Polymer Nanocomposites ◽  
High Performance ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
High Productivity ◽  
Macro Scale ◽  
The Matrix ◽  
Multiscale Structures ◽  
Printing Direction

Polymer nanocomposites have advantages in mechanical, electrical, and optical properties compared to individual components. These unique properties of the nanocomposites have attracted attention in many applications, including electronics, robotics, biomedical fields, automotive industries. To achieve their high performance, it is crucial to control the orientation of nanomaterials within the polymer matrix. For example, the electric conductivity will be maximized in the ordered direction of conductive nanomaterials such as graphene and carbon nanotubes (CNTs). Conventional fabrication methods are commonly used to obtain polymer nanocomposites with the controlled alignment of nanomaterials using electric or magnetic fields, fluid flow, and shear forces. Such approaches may be complex in preparing a manufacturing system, have low fabrication rate, and even limited structure scalability and complexity required for customized functional products. Recently, additive manufacturing (AM), also called 3D printing, has been developed as a major fabrication technology for nanocomposites with aligned reinforcements. AM has the ability to control the orientation of nanoparticles and offers a great way to produce the composites with cost-efficiency, high productivity, scalability, and design flexibility. Herein, we propose a manufacturing process using AM for the architected structure of polymer nanocomposites with oriented nanomaterials using a polylactic acid polymer as the matrix and graphite and CNTs as fillers. AM can achieve the aligned orientation of the nanofillers along the printing direction. Thus, it enables the fabrication of multifunctional nanocomposites with complex shapes and higher precision, from micron to macro scale. This method will offer great opportunities in the advanced applications that require complex multiscale structures such as energy storage devices (e.g., batteries and supercapacitors) and structural electronic devices (e.g., circuits and sensors).

High Performance Phase Retrieval Code for 3D Nanometer Scale Strain Mapping

2021 ◽  
Author(s):  
McKayla Townsend ◽  
Barbara Frosik ◽  
Hyrum Taylor ◽  
Landon Schnebly ◽  
Richard L. Sandberg ◽  
...  
Keyword(s):  
High Performance ◽  
Phase Retrieval ◽  
Nanometer Scale ◽  
Strain Mapping

Nonlinear Combination Resonances in Cantilever Composite Plates

1995 ◽  
Author(s):  
Kyoyul Oh ◽  
Ali H. Nayfeh
Keyword(s):  
Natural Frequencies ◽  
Excitation Frequency ◽  
Power Spectra ◽  
Low Frequency ◽  
Composite Plates ◽  
High Amplitude ◽  
Mode Shapes ◽  
Laser Vibrometer ◽  
Combination Resonance ◽  
Response Curves

Abstract We experimentally investigated nonlinear combination resonances in a graphite-epoxy cantilever plate having the configuration (–75/75/75/ – 75/75/ – 75)s. As a first step, we compared the natural frequencies and mode shapes obtained from the finite-element and experimental modal analyses. The largest difference in the obtained frequencies was 2.6%. Then, we transversely excited the plate and obtained force-response and frequency-response curves, which were used to characterize the plate dynamics. We acquired time-domain data for specific input conditions using an A/D card and used them to generate time traces, power spectra, pseudo-state portraits, and Poincaré maps. The data were obtained with an accelerometer monitoring the excitation and a laser vibrometer monitoring the plate response. We observed the external combination resonance Ω≈12(ω2+ω5) and the internal combination resonance Ω≈ω8≈12(ω2+ω13), where the ωi are the natural frequencies of the plate and Ω is the excitation frequency. The results show that a low-amplitude high-frequency excitation can produce a high-amplitude low-frequency motion.

Flexural Vibrations of a Multi-Material Microhydraulic Hose Subjected to External Excitation. Experimental Research and Theoretical Description

2021 ◽  
Author(s):  
Marek Lubecki ◽  
Michał Stosiak ◽  
Mirosław Bocian ◽  
Kamil Urbanowicz
Keyword(s):  
Experimental Research ◽  
Natural Frequencies ◽  
Excitation Frequency ◽  
Classical Equation ◽  
Analytical Description ◽  
Theoretical Description ◽  
Laser Vibrometer ◽  
Flexural Vibrations ◽  
Stiffness And Damping ◽  
Mathematica Software

Abstract The paper presents experimental research and mathematical modeling of flexural vibrations of a composite hydraulic microhose. The tested object was a Polyflex 2020N-013V30 hydraulic microhose, consisting of a braided aramid layer placed in a thermoplastic matrix. The vibrations were induced with an external electromagnetic exciter in the range from 0 Hz to 100 Hz using the sweep function. Using a laser vibrometer, the exciter’s displacement was measured in the above-mentioned range. Long exposure photographs were taken to identify the form of microhose’s vibrations as well as to measure it’s amplitude. The existence of considerable non-linearity in subsequent natural frequencies was shown. At the same time, mathematical simulations were carried out using the Mathematica software. For the analytical description of the object’s vibrations partial differential equations based on the string equation were used. A part responsible for damping in the material was added to the classical equation of the string. The dependence of the values of the stiffness and damping coefficients a on the excitation frequency made it possible to model nonlinearities manifested by the upward shift of higher natural frequencies and the suppression of the amplitudes of successive modes. Further development of the proposed model will allow for modeling the internal pressure in the hose and its effect on transverse vibrations. It will also allow to design of vibrations of composite microhoses and avoid the coupling of these vibrations with external excitations.

Accelerated Discovery and Design of Nano-Material Applications in Nuclear Power by Using High Performance Scientific Computing

2015 ◽  
pp. 83-118
Author(s):  
Liviu Popa-Simil
Keyword(s):  
Nuclear Power ◽  
High Performance ◽  
Scientific Computing ◽  
Material Behavior ◽  
Nano Materials ◽  
Macro Scale ◽  
Material Systems ◽  
Nano Material ◽  
And Performance

The accelerated development of nano-sciences and nano-material systems and technologies is made possible through the use of High Performance Scientific Computing (HPSC). HPSC exploration ranges from nano-clusters to nano-material behavior at mezzo-scale and specific macro-scale products. These novel nano-materials and nano-technologies developed using HPSC can be applied to improve nuclear devices' safety and performance. This chapter explores the use of HPSC.

Hierarchical Multiscale Modeling of Tire–Soil Interaction for Off-Road Mobility Simulation

2019 ◽  
Vol 14 (6) ◽  
Author(s):  
Hiroki Yamashita ◽  
Guanchu Chen ◽  
Yeefeng Ruan ◽  
Paramsothy Jayakumar ◽  
Hiroyuki Sugiyama
Keyword(s):  
High Performance ◽  
Computational Models ◽  
Computational Cost ◽  
Interaction Model ◽  
High Fidelity ◽  
Wheel Load ◽  
Mobility Performance ◽  
Wide Range ◽  
Computationally Intensive ◽  
Soil Bin

A high-fidelity computational terrain dynamics model plays a crucial role in accurate vehicle mobility performance prediction under various maneuvering scenarios on deformable terrain. Although many computational models have been proposed using either finite element (FE) or discrete element (DE) approaches, phenomenological constitutive assumptions in FE soil models make the modeling of complex granular terrain behavior very difficult and DE soil models are computationally intensive, especially when considering a wide range of terrain. To address the limitations of existing deformable terrain models, this paper presents a hierarchical FE–DE multiscale tire–soil interaction simulation capability that can be integrated in the monolithic multibody dynamics solver for high-fidelity off-road mobility simulation using high-performance computing (HPC) techniques. It is demonstrated that computational cost is substantially lowered by the multiscale soil model as compared to the corresponding pure DE model while maintaining the solution accuracy. The multiscale tire–soil interaction model is validated against the soil bin mobility test data under various wheel load and tire inflation pressure conditions, thereby demonstrating the potential of the proposed method for resolving challenging vehicle-terrain interaction problems.

Flow Characteristics of Fluid Droplet Obtained From Air Assisted Atomizer

2011 ◽  
Author(s):  
Pipatpong Watanawanyoo ◽  
Hirofumi Mochida ◽  
Hiroyuki Hirahara ◽  
Sumpun Chaitep
Keyword(s):  
Mass Flow ◽  
Cone Angle ◽  
Flow Ratio ◽  
Test Liquid ◽  
Solid Cone ◽  
Spray Cone ◽  
Supply Pressure ◽  
Liquid Mass ◽  
Air Supply ◽  
Mass Flow Ratio

Air assisted atomizer system was designed and developed for fuel injection. The present purpose is to utilize a low pressure in supplying of atomized fuel. Distilled water was used as test liquid on the experiments for the system of atomization. The results revealed air assisted atomizer had a capability to inject the test liquid in the range of the rates of 0.0019–0.00426 kg/s, with the use of air pressure supplied from 68.9 to 689 kPa. In this research, the test liquid supply pressure was kept constant and the air flow rate through the atomizer was varied over a range of air supply pressure to obtain the variation in air liquid mass flow ratio (ALR). The spray solidity was studied by taking pictures of the spray at different liquid air supply pressures. The experimental investigations suggest that spray cone angle tends to increase with increasing in air liquid mass flow ratio because the kinetic energy of the flow keeps on increasing. The solid cone spray has a pattern of penetration depth between 408–446 mm. and cone angle between 14.5–23.6°. It was observed that spray formed the solid cone at all the operating conditions.

scholarly journals Hybrid Spider Silk with Inorganic Nanomaterials

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1853
Author(s):  
Aleksandra P. Kiseleva ◽  
Grigorii O. Kiselev ◽  
Valeria O. Nikolaeva ◽  
Gulaim Seisenbaeva ◽  
Vadim Kessler ◽  
...  
Keyword(s):  
Hybrid Materials ◽  
High Performance ◽  
Spider Silk ◽  
Inorganic Compounds ◽  
Silk Fibers ◽  
Surface Areas ◽  
Macro Scale ◽  
Performance Functional ◽  
Inorganic Nanomaterials ◽  
Functional Components

High-performance functional biomaterials are becoming increasingly requested. Numerous natural and artificial polymers have already demonstrated their ability to serve as a basis for bio-composites. Spider silk offers a unique combination of desirable aspects such as biocompatibility, extraordinary mechanical properties, and tunable biodegradability, which are superior to those of most natural and engineered materials. Modifying spider silk with various inorganic nanomaterials with specific properties has led to the development of the hybrid materials with improved functionality. The purpose of using these inorganic nanomaterials is primarily due to their chemical nature, enhanced by large surface areas and quantum size phenomena. Functional properties of nanoparticles can be implemented to macro-scale components to produce silk-based hybrid materials, while spider silk fibers can serve as a matrix to combine the benefits of the functional components. Therefore, it is not surprising that hybrid materials based on spider silk and inorganic nanomaterials are considered extremely promising for potentially attractive applications in various fields, from optics and photonics to tissue regeneration. This review summarizes and discusses evidence of the use of various kinds of inorganic compounds in spider silk modification intended for a multitude of applications. It also provides an insight into approaches for obtaining hybrid silk-based materials via 3D printing.

scholarly journals Quantifying High-Performance Material Microstructure Using Nanomechanical Tools with Visual and Frequency Analysis

Scanning ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Emil Sandoz-Rosado ◽  
Michael R. Roenbeck ◽  
Kenneth E. Strawhecker
Keyword(s):  
Mechanical Properties ◽  
Frequency Analysis ◽  
Visual Processing ◽  
High Performance ◽  
Mechanical Performance ◽  
Structure Property ◽  
Spatially Resolved ◽  
Macro Scale ◽  
Organization Strategy ◽  
Stiffness Scanning

High-performance materials like ballistic fibers have remarkable mechanical properties owing to specific patterns of organization ranging from the molecular scale, to the micro scale and macro scale. Understanding these strategies for material organization is critical to improving the mechanical properties of these high-performance materials. In this work, atomic force microscopy (AFM) was used to detect changes in material composition at an extremely high resolution with transverse-stiffness scanning. New methods for direct quantification of material morphology were developed, and applied as an example to these AFM scans, although these methods can be applied to any spatially-resolved scans. These techniques were used to delineate between subtle morphological differences in commercial ultra-high-molecular-weight polyethylene (UHMWPE) fibers that have different processing conditions and mechanical properties as well as quantify morphology in commercial Kevlar®, a high-performance material with an entirely different organization strategy. Both frequency analysis and visual processing methods were used to systematically quantify the microstructure of the fiber samples in this study. These techniques are the first step in establishing structure-property relationships that can be used to inform synthesis and processing techniques to achieve desired morphologies, and thus superior mechanical performance.

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