Thermoluminescence, elastic and dielectric investigations of calcium fluoro borophosphate glass composite materials doped by small concentrations of TiO2

Author(s):  
Ravi Kumar Guntu ◽  
N. Jahangeer ◽  
Ch. Srinivasa Rao
2013 ◽  
Vol 133 (7) ◽  
pp. 280-284
Author(s):  
Hideaki Takano ◽  
Chisaki Takubo ◽  
Kengo Asai ◽  
Yuichi Sawai ◽  
Tadashi Fujieda ◽  
...  

2017 ◽  
Vol 14 (2) ◽  
pp. 91
Author(s):  
Atik Bintoro

The twin-boom structure is a component of LSU-5 unmanned aireal vehicle (UAV) construction wich was produced by Aeronautic Technology Center of LAPAN. This structure serves as a stabilizer UAV movements. In operations, the structure will recieve flight load which could result as the structure deflection. Through analytical methods involving the mission, dimensions and configuration of the structure of the twin-boom LSU 05 UAV, has done research to determine the extent of the ability of the structure in the fligth load, so the resulting deflection. From this research it was known that at flighting during 130 minutes, starting from take off the beginning of the flight until  cruising with maximum velocity in 130 km/h, the maximum deflection that occurred in the structure only reaches 5.593 x 10-6 m, with a safety factor of 1.3, it’s means that the structure was relatively save. While at the landing on a relatively save was velocity below 14 km/h. If landing at the velocity exceeding 20 km/h can be believed that the twin-boom structure suffered severe damage, because the stress occurs already exceeded from 650 MPa as the yield strenght of e-glass composite materials. Abstrak:Struktur twin boom merupakan salah satu komponen konstruksi pesawat terbang nir awak LSU-05 hasil karya Pusat Teknologi Penerbangan - LAPAN. Struktur ini berfungsi sebagai penyetabil gerakan pesawat. Dalam operasionalnya, struktur menerima beban terbang yang dapat mengakibatkan timbulnya lendutan. Melalui metode analitis yang melibatkan misi, dimensi dan konfigurasi struktur twin boom pesawat LSU-05, telah dilakukan penelitian untuk mengetahui sejauh mana kemampuan struktur dalam menerima beban terbang, sehingga mengakibatkan lendutan tersebut. Dari penelitian ini diketahui bahwa pada saat penerbangan, selama 130 menit mulai dari tinggal landas di awal penerbangan sampai dengan terbang jelajah pada kecepatan maksimal 130 km/jam, lendutan maksimal yang terjadi pada struktur hanya mencapai 5,593 x 10-6 m, dengan faktor keamanan sebesar 1,3 berarti struktur relatif aman. Sedangkan untuk pendaratan, kecepatan yang relatif aman dapat dilakukan di bawah 14 km/jam. Jika mendarat pada kecepatan melebihi 20 km/jam, struktur twin boom tersebut mengalami kerusakan parah, karena tegangan yang terjadi sudah melebihi 650 MPa sebagai tegangan ijin bahan struktur yakni komposit e-glass.


2009 ◽  
Vol 63 (4) ◽  
pp. 575-586 ◽  
Author(s):  
Zhihua Zhou ◽  
Qingfeng Yi ◽  
Xiaoping Liu ◽  
Lihua Liu ◽  
Qingquan Liu

Author(s):  
Chris Alexander ◽  
Carl Brooks

Composite materials are widely recognized as a resource for repairing damaged pipelines. The fibers in conventional composite repair systems typically incorporate E-glass and carbon materials. To provide greater levels of reinforcement a system was developed that incorporates steel half shells and an E-glass composite repair system. In comparison with other competing composite technologies, the hybrid system has a significant capacity to reduce strain in corroded pipeline to a level that has not been seen previously. Specifically, the hybrid system was used to reinforce a pipe sample having 75% corrosion subjected to cyclic pressure at 36% SMYS. This sample cycled 767,816 times before a leak failure developed. Furthermore, recent testing has demonstrated that the hybrid system actually places the pipeline in compression during installation. This paper will provide results on a series of specifically-designed tests to evaluate the performance of the hybrid system and the implications in relation to the service of actual pipelines.


2016 ◽  
Vol 16 (4) ◽  
pp. 3899-3903 ◽  
Author(s):  
Hongchen Zhang ◽  
Junping Meng ◽  
Jinsheng Liang ◽  
Jie Liu ◽  
Zhaoyang Zeng

Tourmaline/glass composite materials were prepared by sintering at 600 °C using micron-size tourmaline mineral and glass powders as raw materials. The glass has lower melting point than the transition temperature of tourmaline. The Fourier transform infrared spectroscopy showed that the far infrared emissivity of composite was significantly higher than that of either tourmaline or glass powders. A highest far infrared emissivity of 0.925 was obtained when the dosage of tourmaline was 10 wt%. The effects of the amount of tourmaline on the far infrared emission properties of composite was also systematically studied by field emission scanning electron microscope and X-ray diffraction. The tourmaline phase was observed in the composite, showing a particle size of about 70 nm. This meant that the tourmaline particles showed nanocrystallization. They distributed homogenous in the glass matrix when the dosage of tourmaline was not more than 20 wt%. Two reasons were attributed to the improved far infrared emission properties of composite: the particle size of tourmaline-doped was nanocrystallized and the oxidation of Fe2+ (0.076 nm in radius) to Fe3+ (0.064 nm in radius) took place inside the tourmaline-doped. This resulted in the shrinkage of unit cell of the tourmaline in the composite.


1992 ◽  
Vol 49 (6) ◽  
pp. 277-279
Author(s):  
B. S. Batalin ◽  
H. A. Pravina

Author(s):  
Wensong Yang ◽  
Assimina A. Pelegri

Considering the wide applications of composite materials, it is necessary understand the dynamic effects of damage mechanisms, including matrix cracking and interfacial debonding, on the stiffness performance of these materials. Strain rates may have a significant effect on the dynamic behavior of composite materials subjected to dynamic loadings. In this study, a numerical approach with the finite element code ABAQUS is used to develop a failure criterion to express the effect of static and dynamic damage mechanisms on the composite’s stiffness under uniaxial tensile loading. A random epoxy/glass composite material is investigated under three strain rates: quasi-static, intermediate, and high, here 10−4, 1, and 200 s−1, respectively. The results illustrate that the interfacial debonding increases as the strain rate increases in random epoxy/glass composite materials. At the same time, the normalized stiffness components exhibit different trends with strain rate increase due to their connection to matrix cracking or interfacial debonding.


2006 ◽  
Vol 45 ◽  
pp. 1986-1995 ◽  
Author(s):  
William Edward Lee ◽  
J. Juoi ◽  
M.I. Ojovan ◽  
O.K. Karlina

The basic principles of incorporating high level radioactive waste into glasses, ceramics and glass composite materials (GCMs) are described. Current UK technology uses glass wasteforms for the products of reprocessing while some waste streams may be incorporated in ceramics and difficult or legacy wastes will require the development of other wasteforms many of which will be GCMs. Processingproperty- structure relations in novel wasteforms are described including the use of self-sustaining reactions to produce a composite ceramic wasteform based on TiC and Al2O3 from irradiated graphite and development of a GCM wasteform for immobilising spent zeolite sand filters.


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