An ultrasonic c-scan system for the NDE of advanced composites

A state-of-the-art computer controlled ultrasonic through transmission jet probe c-scan system for the Non- Destructive Evaluation (NDE) of advanced composites has been set up in the Composite Structures Laboratory (NAL), under the advanced composite technology programme funded by the Aeronautical Development Agency (ADA). The system configuration and specification details were arrived at, after considerable studies, with a view to establish a cost effective c-scan system that would meet most of the NDE requirements of advanced composites, notably that of the CFRP rudder - of the Light Combat Aircraft (LCA). The salient features of the NAL c-scan system are presented in this report. In addition, various aspects of the pre-shipment inspection and acceptance tests carried out at the manufacturer's works as well as during the commissioning at NAL are discussed here

Non-Destructive Evaluation—A Pivotal Technology for Qualification of Composite Aircraft Structures

Tremendous advances in composite materials and a deeper understanding of their behavior have been responsible for the increased use of composites in the development of advanced, new generation civil and military aircraft. Composites play an important role in any aircraft development programme and are strong contenders to their metal counterparts due to their significant contributions towards improving strength, stiffness, fatigue properties & weight reduction. As materials, structural design & processing have evolved, strong emphasis is placed on effective & reliable damage detection, durability and damage tolerance. As a consequence, Non-destructive Evaluation (NDE) has also undergone significant advances towards meeting the growing demands of quality assurance. Advanced Composites Division (ACD) of National Aerospace Laboratories (NAL), has been involved in the development of composite structures for both civil and military aircraft for over a decade and a half. Innovative composite processing methods like co-curing/co-bonding have been successfully employed to realize airworthy structures. The role of NDE in the development of these structures has been critical and not limited to damage detection alone. On several occasions, NDE has provided valuable inputs towards improving design and process parameters. In-spite of the complexity of the structures, stringent quality requirements and tight delivery schedules, NDE has been successful in certifying these composite structures for airworthiness. This paper discusses the implementation of key NDE techniques like ultrasonics, radiography, acoustic emission and thermography for reliable flaw detection, characterization and quality assurance of composite aircraft structures

NALLA-2 : Strain measurements

Strains were monitored for NALLA2 Structural components at critical locations : 60 locations for wing, 50 for fuselage, 6 each for horizontal tail, vertical tail, landing gear and nose gear and 20 locations for wing fuselage joint. While the wing fuselage joint was tested upto the ultimate load, the rest of the components were loaded upto the limit load only. The measured strains have proved the linear behaviour upto the limit Load, with zero yield, validating the structural integrity, of the components

Smart Wall Painting System

The objective of this paper is to outline a smart wall painting system for little and medium scale operations. These days robots are broadly utilized as a part of relatively every application like medicinal application, amusement, military, production lines vehicle businesses, and so on. However, the utilization of robot is as yet not generally utilized as a part of constructional work. Robots are fundamentally design to build speed and maximize accuracy of construction field work. The basic point of the paper is to design, develop and actualize Remote Operated Wall Painting Machine which helps for accomplishing painting hardware requiring little to no effort because of which the sketch work can be effectively done proficiently and in particular at extremely ostensible cost. The painting machine keeps away from coordinate contact of chemicals which can be harmful to the human painters, for example, eye, skin and respiratory system issues.. Besides that the idea of painting method that requires rehashed work time and hand rising make it physical torment, and exertion devouring. Moreover, it would offer the chance to decrease or take out human introduction to troublesome and dangerous worked system conditions, which would take care of a large portion of the issues associated with security when numerous activities happen in the meantime. This machine is is easy to operate and no need of labour required to operate effectively. At the point when development specialists and robots are appropriately coordinated in building tasks,the entire development process can be better overseen and savings in human work and timing are acquired as an outcome. wall painting is a redundant, debilitating and risky process which makes it a perfect case for automation. Painting had been mechanized in car industry however not yet for the development business. There is a strong requirement for a portable robot that can move to paint walls of buildings. In this paper, the conceptual plan of a an autonomous wall painting robot is portrayed comprising of an arm that sweeps the dividers vertically and is fitted on a versatile robot base to give the lateral feed movement to cover the painting area. The design objective is to fulfill the criteria of straight forwardness, low weight, ease and quick painting time. Ultrasonic sensors are fitted on the arm and the portable base to alter as far as possible and move in the room territory. A control system is intended to direct the arm movement and plan the versatile base movement

Use of multidimensional item response theory methods for dementia prevalence prediction: an example using the Health and Retirement Survey and the Aging, Demographics, and Memory Study

Background: Data sparsity is a major limitation to estimating national and global dementia burden. Surveys with full diagnostic evaluations of dementia prevalence are prohibitively resource-intensive in many settings. However, validation samples from nationally representative surveys allow for the development of algorithms for the prediction of dementia prevalence nationally. Methods: Using cognitive testing data and data on functional limitations from Wave A (2001–2003) of the ADAMS study (n = 744) and the 2000 wave of the HRS study (n = 6358) we estimated a two-dimensional item response theory model to calculate cognition and function scores for all individuals over 70. Based on diagnostic information from the formal clinical adjudication in ADAMS, we fit a logistic regression model for the classification of dementia status using cognition and function scores and applied this algorithm to the full HRS sample to calculate dementia prevalence by age and sex. Results: Our algorithm had a cross-validated predictive accuracy of 88% (86–90), and an area under the curve of 0.97 (0.97–0.98) in ADAMS. Prevalence was higher in females than males and increased over age, with a prevalence of 4% (3–4) in individuals 70–79, 11% (9–12) in individuals 80–89 years old, and 28% (22–35) in those 90 and older. Conclusions: Our model had similar or better accuracy as compared to previously reviewed algorithms for the prediction of dementia prevalence in HRS, while utilizing more flexible methods. These methods could be more easily generalized and utilized to estimate dementia prevalence in other national surveys

Design & Development of Bridge Deck Plate Using Composite Materials and sandwich Construction : Concluding Report

This report brings out the gist of the work carried out under the project entitled "Design & Development of Bridge Deck Plate Using Composite Materials & Sandwich Construction" sponsored by R & D Estt. (Engrs.), DRDO, Pun

Acoustic Emission Monitoring of Ammonia Transfer Main Weld Joints

Field tests have-been carried out on gas lines under the service conditions when the plant was in operation. The testing procedure involved monitoring of acoustic emissions at six specified locations on the transfer main. The technique involved in the testing and the observations made during the tests are presented in this report

Tests on Redux Bonded Sandwich Specimens

Tests have been performed, in accordance with ASTM specifications, on sandwich specimens bonded with Redux adhesives with a view to evaluate the performance of the adhesives. In this report, details of the tests conducted and the conclusions drawn from this study are given

Non Destructive Evaluation of MiG-21 Compsoite Rudder Part II - APT Section Adhesive bond qulality Evaluation

This report contains the results of adhesive bond quality evaluation in the aft section of MiG-21 composite rudder using Fokker Bond Tester. Complete test recordings in respect of four different rudders are included in this report