National Aerospace Laboratories

About: National Aerospace Laboratories is a facility organization based out in Bengaluru, India. It is known for research contribution in the topics: Coating & Corrosion. The organization has 1838 authors who have published 2349 publications receiving 36888 citations.

Thermal Aging of Twaron Fibers

Abstract: The residual effects of thermal aging on Twaron fibers have been studied using X-ray diffraction, weight analysis, scanning electron microscopy and tensile testing. X-ray data from isothermally age...

Effect of ply-drop on fatigue life of a carbon fiber composite under a fighter aircraft spectrum load sequence

Abstract: Carbon fiber composite laminate containing symmetric internal ply-drop simulating thickness variation was fabricated and tested to determine fatigue life under a standard mini-FALSTAFF spectrum load sequence. The fatigue life of ply-drop composite was significantly lower than that of plain composite due mainly to initiation and growth of delamination near the ply-drop location. The spectrum fatigue life was also predicted by empirical method. For this purpose, static and constant amplitude fatigue data was generated to construct constant life diagrams (CLDs). The spectrum fatigue life predicted using CLDs was in good agreement with experimental results for both plain and ply-drop composites.

Compression behavior of NbC under nonhydrostatic conditions to 57 GPa

Abstract: The analysis of the diffraction data under nonhydrostatic stress condition created in a diamond anvil cell suggests that the compressive strength of NbC crystallites is at least 24 ± 4 GPa at a confining pressure of 57 ± 0.5 GPa. When using Al as a pressure transmitting medium in the diamond anvil cell pressure conditions become nearly hydrostatic. The bulk modulus derived from the compression data under quasi-hydrostatic pressure condition gives K 0 = 274 ± 3 GPa when fixing K 0 ′ = 4 . This value agrees well with the value obtained from the first-principles numerical calculations.

Fusion of Radar and IRST Sensor Measurements for 3D Target Tracking using Extended Kalman Filter

Abstract: Tracking algorithms for IRST and radar are implemented and their performance is checked with simulated data. Detailed mathematical expressions given could be useful for implementation. Performance evaluation metrics have been presented to check the tracking algorithm performance. Two fusion schemes have been presented and their performances evaluated with simulated data. It is concluded that both fusion schemes performed alike with the second fusion scheme giving slightly better results. From the results, it is also concluded that fusion of IRST and radar would improve the tracking performance and reduce the positional uncertainty compared to individual trackers. Defence Science Journal, 2009, 59(2), pp.175-182 , DOI:http://dx.doi.org/10.14429/dsj.59.1506