The Creep Behavior and Mechanical Properties of Polypropylene (pp) in Mechanical Vibration Injection Molding under Low Frequency Vibration Field

2009 ◽  
Vol 29 (8-9) ◽  
Author(s):  
Y. Lu ◽  
Q. Yang ◽  
K. Shen ◽  
W. Yang ◽  
M-bo Y. Z. Yan
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Creep Behavior ◽  
Mechanical Vibration ◽  
Low Frequency ◽  
Vibration Field ◽  
Low Frequency Vibration

Improved mechanical properties and structure of PP/nano-CaCO3 blends prepared by low-frequency vibration injection molding

2008 ◽  
Vol 57 (1) ◽  
pp. 23-27 ◽  
Author(s):  
Gao Xueqin ◽  
Xu Jing ◽  
Chen Zhanchun ◽  
Deng Cong ◽  
Shen Kaizhi
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Low Frequency ◽  
Low Frequency Vibration

Measurements of Low Frequency Vibration in Subsea Piping Using ROV Video Analysis

2020 ◽  
Author(s):  
Andries van Wijhe ◽  
Lennert Buijs ◽  
Leszek Stachyra ◽  
Olivier Macchion
Keyword(s):  
Video Analysis ◽  
Video Processing ◽  
Production Systems ◽  
Mechanical Vibration ◽  
Water Injection ◽  
Low Frequency ◽  
Free Vibrations ◽  
Accelerometer Data ◽  
Lighting Condition ◽  
Low Frequency Vibration

Abstract Vibrations in Subsea Production Systems are well recognized as a concern in the subsea industry. To identify the severity of the vibrations and potential accumulated fatigue damage, subsea vibrations need to be measured with great accuracy. Currently, accurate detection and subsea measurements are often performed by utilizing accelerometers, which have to be connected to the structure by ROV or a diver. ROV video analysis provides an alternative solution. Video analyses are widely utilized across different applications. With the increased quality of a HD camera on ROV, the accessibility of such measurements is an attractive substitute to other techniques. As a part of on-shore mechanical testing on a full assembled XT in St John’s Canada, a flowloop on a water injection XT was subjected to free vibrations. The vibrations were filmed using a commercial HD camera placed on a tripod. This test was done to validate data generated using video processing in which pipe vibration of an operating subsea XT was filmed using an ROV camera. A study that aimed to quantify the video processing accuracy, limitations and provide general guidance was conducted. For the onshore test filmed with a tripod the results of video analyses were compared with the measurements obtained by means of accelerometers. For the video of an operating subsea XT filmed by an ROV, the obtained vibration frequency and direction was compared with the free mechanical vibration obtained by a FEM model. The results obtained by means of the video analysis matched well with the accelerometer data. A high accuracy was reached, as vibration displacements as low as 20% of the pixel were accurately determined in the video analysis. With respect to detection frequencies, the upper cut-off frequency was around 15 Hz determined by the video framerate. The video analysis utilizing ROV videos was found to be applicable for low frequency vibration measurements, opening the opportunity for easier and more cost effective vibration detection and monitoring. The method is also reliable for subsea application in which the camera is placed on an ROV and is thus not affected by ROV movements, subsea lighting condition and moving ocean debris.

scholarly journals Application of Digital Image Correlation to Measurement of Packaging Material Mechanical Properties

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jian-Wei Zhou ◽  
Dong-Hong Liu ◽  
Lan-Yuan Shao ◽  
Zhen-Lin Wang
Keyword(s):  
Mechanical Properties ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Poisson Ratio ◽  
Low Frequency ◽  
Measurement Range ◽  
Image Correlation ◽  
Packaging Materials ◽  
Entire Area ◽  
Low Frequency Vibration

Among various packaging materials, papers and polymer plastics are the most common due to their light weights, low costs, and other advantages. However, their mechanical properties are difficult to measure precisely because of their softness. To overcome the difficulty, a new measure instrument prototype is proposed based on an optical method known as the digital image correlation (DIC). Experiments are designed to apply the DIC to measure mechanical properties of flexible packaging materials, including the stress-strain relationship, the Poisson ratio, the coefficient of heat expansion, the creep deformation, and the top-pressure deformation of corrugated box. In addition, the low frequency vibration of package is simulated, and the vibration frequencies are measured by DIC. Results obtained in the experiments illustrate the advantages of the DIC over traditional methods: noncontact, no reinforced effect, high precision over entire area, wide measurement range, and good measurement stability.

scholarly journals Finite Element Investigation of the Effects of the Low-Frequency Vibration Generated by Vehicle Driving on the Human Lumbar Mechanical Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Ruo-xun Fan ◽  
Jie Liu ◽  
Yong-li Li ◽  
Jun Liu ◽  
Jia-zi Gao
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Lumbar Spine ◽  
Nucleus Pulposus ◽  
Vibrational Frequency ◽  
Low Frequency ◽  
Fluid Loss ◽  
Low Frequency Vibration ◽  
Human Lumbar Spine

Long-term exposure to low-frequency vibration generated by vehicle driving impairs human lumbar spine health. However, few studies have investigated how low-frequency vibration affects human lumbar mechanical properties. This study established a poroelastic finite element model of human lumbar spinal segments L2–L3 to perform time-dependent vibrational simulation analysis and investigated the effects of different vibrational frequencies generated by normal vehicle driving on the lumbar mechanical properties in one hour. Analysis results showed that vibrational load caused more injury to lumbar health than static load, and vibration at the resonant frequency generated the most serious injury. The axial effective stress and the radial displacement in the intervertebral disc, as well as the fluid loss in the nucleus pulposus, increased, whereas the pore pressure in the nucleus pulposus decreased with increased vibrational frequency under the same vibrational time, which may aggravate the injury degree of human lumbar spine. Therefore, long-term driving on a well-paved road also induces negative effects on human lumbar spine health. When driving on a nonpaved road or operating engineering machinery under poor navigating condition, the auto seat transmits relatively high vibrational frequency, which is highly detrimental to the lumbar spine health of a driver.

scholarly journals Ligand-dependent nano-mechanical properties of CdSe nanoplatelets: calibrating nanobalances for ligands affinity monitoring.

Nanoscale ◽  
2021 ◽  
Author(s):  
Quentin Martinet ◽  
Justine Baronnier ◽  
Adrien Girard ◽  
Tristan Albaret ◽  
Lucien Saviot ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Raman Scattering ◽  
Cadmium Selenide ◽  
Vibration Frequency ◽  
Low Frequency ◽  
Frequency Shifts ◽  
Low Frequency Vibration

The influence of ligands on the low frequency vibration of different thicknesses cadmium selenide colloidal nanoplatelets is investigated using resonant low frequency Raman scattering. The strong vibration frequency shifts induced...

scholarly journals Specifics of Reduction-Oxidation Processes Exposed to a Low--Frequency Acoustic Field

2020 ◽  
pp. 80-92
Author(s):  
G.N. Fadeev ◽  
V.S. Boldyrev ◽  
N.A. Bogatov ◽  
A.L. Nikolaev
Keyword(s):  
Acoustic Field ◽  
Oxidation Process ◽  
Low Frequency ◽  
Blue Dye ◽  
Active Components ◽  
Low Frequencies ◽  
Oxidation Processes ◽  
Vibration Field ◽  
Low Frequency Vibration ◽  
Qualitative Estimation

The investigation concerned the effects of low-frequency vibrations on a system consisting of two biochemically active components: methylene blue dye and ascorbic acid. Each component can be reversibly oxidized and reduced. This system allows us to trace the effect that a low-frequency vibration field has on the reciprocal reduction-oxidation process and detect specific features of this type of exposure. We discovered that reduction-oxidation processes in such systems do not accelerate but slow down when exposed to low frequencies, unlike those in the previously studied clathrate and chelate structures. We observe an inhibition effect concerning the sonochemical process in a low-frequency acoustic field. We performed a qualitative estimation of the effect.

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