scholarly journals Damping characteristics of the Ti-rich TiNi melt-spun ribbon measured by using a dynamic mechanical analyzer

2010 ◽  
Vol T139 ◽  
pp. 014012 ◽  
Author(s):  
S H Chang ◽  
T H Chen ◽  
S K Wu ◽  
K N Lin
2005 ◽  
Vol os-14 (4) ◽  
pp. 1558925005os-14
Author(s):  
Diana L. Ortiz ◽  
Robert L. Shambaugh

Polybutylene (PB-1) fibers were spun at spinning speeds of 250–2500 m/min. A tensile tester was used to analyze the stress-strain behavior of these fibers. In addition, birefringence and the effect of aging were examined. A DMA (dynamic mechanical analyzer) was used to measure the storage modulus and loss modulus of the fibers. Nonwoven mats of the fibers were prepared and compression tests were run on these mats. The properties of the polybutylene fibers and mats were compared with the properties of common polypropylene fibers and mats.


2021 ◽  
Vol 5 (3) ◽  
pp. 80
Author(s):  
George Youssef ◽  
Scott Newacheck ◽  
Nha Uyen Huynh ◽  
Carlos Gamez

Fiber-reinforced polymer matrix composites continue to attract scientific and industrial interest since they offer superior strength-, stiffness-, and toughness-to-weight ratios. The research herein characterizes two sets of E-Glass/Epoxy composite skins: stressed and unstressed. The stressed samples were previously installed in an underground power distribution vault and were exposed to fire while the unstressed composite skins were newly fabricated and never-deployed samples. The mechanical, morphological, and elemental composition of the samples were methodically studied using a dynamic mechanical analyzer, a scanning electron microscope (SEM), and an x-ray diffractometer, respectively. Sandwich composite panels consisting of E-glass/Epoxy skin and balsa wood core were originally received, and the balsa wood was removed before any further investigations. Skin-only specimens with dimensions of ~12.5 mm wide, ~70 mm long, and ~6 mm thick were tested in a Dynamic Mechanical Analyzer in a dual-cantilever beam configuration at 5 Hz and 10 Hz from room temperature to 210 °C. Micrographic analysis using the SEM indicated a slight change in morphology due to the fire event but confirmed the effectiveness of the fire-retardant agents in quickly suppressing the fire. Accompanying Fourier transform infrared and energy dispersive X-ray spectroscopy studies corroborated the mechanical and morphological results. Finally, X-ray diffraction showed that the fire event consumed the surface level fire-retardant and the structural attributes of the E-Glass/Epoxy remained mainly intact. The results suggest the panels can continue field deployment, even after short fire incident.


2019 ◽  
Vol 6 (10) ◽  
pp. 105317 ◽  
Author(s):  
R Karthicksundar ◽  
Balaji Rajendran ◽  
P K Dinesh Kumar ◽  
S Devaganesh

Author(s):  
Shutian Yan ◽  
Jie Deng ◽  
Chulheung Bae ◽  
Xinran Xiao

Battery separators are thin, porous membrane of 20∼30 microns thickness. Polymer separators display a significant amount of shrinkage at elevated temperatures. It is difficult to quantitatively characterize the large shrinkage behavior with a free standing separator sample. This paper examines the use of a dynamic mechanical analyzer under tensile mode in measuring the coefficient of thermal expansion (CTE) of three commonly used separators.


2012 ◽  
Vol 557-559 ◽  
pp. 1624-1628 ◽  
Author(s):  
Xian Lan Liu ◽  
Chu Ming Liu ◽  
Wen Yu Zhang ◽  
Jian Hua Luo ◽  
Su Min Zeng

The dynamic mechanical analyzer (DMA) was applied to investigate the damping properties of Mg-6Zn-0.6Zr alloys. The results show that the as-cast Mg-6Zn-0.6Zr alloy exhibits higher strain amplitude independent damping performance than that of as-homogenized. The strain amplitude dependent damping of the as-homogenized has the best damping performance with the strain amplitude from 3×10-5 to 6×10-4, and the as-extruded is the lowest. When the strain amplitude exceeded 6×10-4, the as-extruded has the best damping capacity all the time within the experimental strain amplitude, and all the alloys reach the high damping capacity. Two critical strain amplitude points were detected in the alloy as-extruded and as-homogenized. The damping peak value is 0.0192 with the strain amplitude of 1.5×10-3 presented in the alloy as-extruded.


Author(s):  
Ke-cheng Chen ◽  
Dong Li ◽  
Li-jun Wang ◽  
Necati Özkan ◽  
Xiao Dong Chen ◽  
...  

Dynamic viscoelastic properties of brown rice kernels were investigated using a dynamic mechanical analyzer (DMA). In order to meet the sample requirements for the DMA and prevent moisture loss of rice kernels during the DMA measurements, necessary precautions were taken. To prevent moisture loss of rice kernels during the DMA measurements at temperatures ranging from room temperature to 120 degrees centigrade, rice kernels were wrapped with a thin layer of sealing film. Then the wrapped rice kernels were additionally covered with an aluminum foil. Two ends of the wrapped brown rice kernels were cut with a razor blade; subsequently both ends of the cut rice kernels were filed using fine sandpaper to produce near cylindrical rice kernels with parallel ends. The storage modulus of the rice kernels decreased with increasing temperature and moisture content. The loss modulus and the tan delta (loss factor) of the rice kernels as a function of temperature showed clear peaks, which are associated with the glass transition of rice kernels. Two rice varieties had been investigated, and the results showed that the dynamic viscoelastic properties of these rice samples were not significantly different. The glass transition temperatures for the long-grain rice kernels with the moisture contents of 17.4, 13.8, and 10.9 wt.% were determined as 45, 58, and 66 degrees centigrade, respectively.


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