Artificial neural network based delamination prediction in composite plates using vibration signals

Dynamic loading on composite components may induce damages such as cracks, delaminations, etc. and development of an early damage detection technique for delaminations is one of the most important aspects in ensuring the integrity and safety of composite components. The presence of damages such as delaminations on the composites reduces its stiffness and further changes the dynamic behaviour of the structures. As the loss in stiffness leads to changes in the natural frequencies, mode shapes, and other aspects of the structure, vibration analysis may be the ideal technique to employ in this case. In this research work, the supervised feed-forward multilayer back-propagation Artificial Neural Network (ANN) is used to determine the position and area of delaminations in GFRP plates using changes in natural frequencies as inputs. The natural frequencies were obtained by finite element analysis and results are validated by experimentation. The findings show that the suggested technique can satisfactorily estimate the location and extent of delaminations in composite plates

Natural Frequency based delamination estimation in GFRP beams using RSM and ANN

The importance of delamination detection can be understood from aircraft components like Vertical Stabilizer, which is subjected to heavy vibration during the flight movement and it may lead to delamination and finally even flight crash can happen because of that. Any solid structure's vibration behaviour discloses specific dynamic characteristics and property parameters of that structure. This research investigates the detection of delamination in composites using a method based on vibration signals.  The composite material's flexural stiffness and strength are reduced as a result of delaminations, and vibration properties such as natural frequency responses are altered. In inverse problems involving vibration response, the response signals such as natural frequencies are utilized to find the location and magnitude of delaminations. For different delaminated beams with varying position and size, inverse approaches such as Response Surface Methodology (RSM) and Artificial Neural Network (ANN) are utilized to address the inverse problem, which aids in the prediction of delamination size and location

Brain-Controlled Telepresence Robot By Motor-Disabled People

ABSTRACT: In this paper we present the first results of users with disabilities in mentally controlling a telepresence robot, a rather complex task as the robot is continuously moving and the user must control it for a long period of time (over 6 minutes) to go along the whole path. These two users drove the telepresence robot from their clinic more than 100 km away. Remarkably, although the patients had never visited the location where the telepresence robot was operating, they achieve similar performances to a group of four healthy users who were familiar with the environment. In particular, the experimental results reported in this paper demonstrate the benefits of shared control for brain-controlled telepresence robots. It allows all subjects (including novel BMI subjects as our users with disabilities) to complete a complex task in similar time and with similar number of commands to those required by manual control

Ethnobotanical Survey of Folklore Plants for the Treatment of Jaundice and Snakebites in Vellore Districts of Tamilnadu, India

An ethnobotanical survey was undertaken to collect information from local people about the use of medicinal plants in Vellore district. Local people use certain folklore medicinal plants for the treatment of Jaundice and Snakebite. The Knowledge about the medicinal plants has been transmitted orally from generation. The investigations revealed that there are about 22 species of plants to treat Jaundice and Snakebite. Jaundice and Snakebite are the common problems among the local people. The study indicates that the local inhabitants rely on medicinal plants for treatment

Investigation of population structure and molecular genetic diversity under coastal agro-ecosystem in rice (Oryza sativa L.)

Molecular markers are useful tools for evaluating genetic diversity and determining cultivar identity. Thirty nine simple sequence repeat (SSR) markers were selected in order to evaluate the genetic diversity in 88 genotypes. A total of 115 alleles were detected in 39 SSR polymorphic markers. The number of alleles per marker ranged from 1 to 5, with an average of 3 alleles per locus. An average polymorphism information content value of 0.5615 was recorded. It ranged from zero (RM431, RM379 and RM262) to 0.6476 (RM324), indicating significant genetic diversity among and within the rice accessions of the present study. The average observed heterozygosity was 0.1136, while the average expected genetic diversity was 0.6105. A dendrogram constructed using the Unweighted Pair Group Method with Arithmetic means (UPGMA), grouped the 88 rice genotypes into three well differentiated major clusters. The structured program without prior information provided support for the existence of three genetically distinct clusters (K=3)

Conventional and Additively Manufactured Stainless Steels: A Review

© The Indian Institute of Metals - IIM 2021. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1007/s12666-021-02305-7For the last three decades, enormous manufacturing processes have been widely employed in the field of transportation (aviation, automobile and marine) as well as various industrial sectors. Among the invented techniques, conventional manufacturing plays a versatile and cost effective role, but additive manufacturing (AM) possesses a more significant advantage of handling complicated parts or complex geometrical structures. The conventional processes were used from ancient times until the development of other advanced techniques. In recent development of technology, AM technology has shown a tremendous change in the manufacturing field. The process of development in AM began with polymers, then to composites and advanced to nanocomposites, continuously. AM provides a waste-free production management system with enhanced processes. Therefore, this detailed and compendious review describes the different stainless steels fabricated through conventional and AM techniques. It is evident that AM proves better than other several conventional techniques, by three dimensional (3D) printing of quality and complex stainless steels components that are impossible to manufacture through other methods. Notwithstanding, there still need of much efforts to improve AM technique by reducing the manufacturing cost, supporting mass production and printing large stainless steel components. With an increase in invention of various efficient state-of-the-art engineering software, robots in manufacturing, artificial intelligence and smart manufacturing, the aforementioned drawbacks of AM technique/3D printing of various stainless steel structures will be soon eradicated.Peer reviewe

Effect of chemical treatments on physical properties of kenaf bast fibres

In the present study, kenaf bast fibre surfaces have been modified using different chemicals with varying concentration. The effects of these chemical treatments on moisture content, water absorption, fibre diameter and bundle strength are investigated. The benefit of chemical treatments in the removal of impurities from the fibre surfaces has been established by scanning electron microscopy. It is found that the fibres treated with sodium hydroxide and acetic acid show major effect on fibre diameter. Compared to untreated kenaf fibre, strong alkali (NaOH) treatment show maximum water absorption (78.76%) and moisture content (8.15%). In fibre bundle tensile strength, sodium hydroxide and sodium carbonate treated fibres show more than 80% improvement in the tensile strength of fibre. Kenaf fibre treated with 10% Na2CO3 show highest tensile strength of 410 MPa

Artificial neural network based delamination prediction in composite plates using vibration signals

Dynamic loading on composite components may induce damages such as cracks, delaminations, etc. and development of an early damage detection technique for delamination prediction is one of the most important aspects in ensuring the integrity and safety of such components. The presence of damages such as delaminations on the composites reduces its stiffness and changes the dynamic behaviour of the structures. As the loss in stiffness leads to changes in the natural frequencies, mode shapes, and other aspects of the structure, vibration analysis may be the ideal technique for delamination prediction. In this research work, the supervised feed-forward multilayer back-propagation Artificial Neural Network is used to determine the position and area of delaminations in glass fiber-reinforced polymer (GFRP) plates using changes in natural frequencies as inputs. The natural frequencies were obtained by finite element analysis and results are validated experimentally. The findings show that the suggested technique can satisfactorily estimate the location and extent of delaminations in composite plates

Performance Comparison of Static CMOS and Domino Logic Style in VLSI Design: A Review

Of late, there is a steep rise in the usage of handheld gadgets and high speed applications. VLSI designers often choose static CMOS logic style for low power applications. This logic style provides low power dissipation and is free from signal noise integrity issues. However, designs based on this logic style often are slow and cannot be used in high performance circuits. On the other hand designs based on Domino logic style yield high performance and occupy less area. Yet, they have more power dissipation compared to their static CMOS counterparts. As a practice, designers during circuit synthesis, mix more than one logic style judiciously to obtain the advantages of each logic style. Carefully designing a mixed static Domino CMOS circuit can tap the advantages of both static and Domino logic styles overcoming their own short comings