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Self-healing is fascinating research due to its distinctiveness in automatically mending the damages. A great deal of work has been done using the self-healing concept in polymers. However, there is limited research on fibre reinforced polymer composites. Adding microcapsules during fabrication of the composites is one of the methods which is capable of carrying out the healing of damage autonomously. This research work takes into account the preparation of fibre reinforced composites with incorporation of two types of microcapsules i.e., healing agent carriers and curing agent carriers in the course of fabrication to mend the damages generated. The work experiments the impact of inclusion of microcapsules on the tensile properties of host composite laminate. Results of tensile tests indicate that a significant amount of tensile strength of the specimens was restored by healing and curing agents present in microcapsules. The healing efficiency was observed as 61.3%. It has also been noted that, the presence of these capsules does not significantly alter the original performance of the laminate as the effect of capsule inclusion on properties of the laminate is negligible. [ABSTRACT FROM AUTHOR]

The adhesively bonded joint creates a strong bond between the adherend and the adhesive and are replacing the riveted joints in numerous fields such as aerospace, automobile and civil sectors. In this study, the consequence of compositions of graphene nanoparticle doped in the epoxy adhesive on the shear behaviour of single lap joints of adhesively bonded glass and carbon fibre as adherends were investigated. Glass and carbon fibre laminates were produced using Rotex EP-306 resin and Rotex EH-758 hardener. Adhesively bonded single lap joints were then made by using a two-part epoxy structural adhesive. Graphene was added in weight percentages of 0.1%, 0.5%, 1% and 2% into the resin and dispersed by using the method of ultrasonication. A shear test was carried to determine the bonding strength. Results indicated that joints with 0.5% wt. of graphene showed better bond strength compared to other configurations for both glass and carbon adherend. It was noted that with further increase in percentage of graphene, the shear strength decreased. Furthermore, the joints made with carbon as adherend showed better strength properties in comparison with joints made of glass adherend. [ABSTRACT FROM AUTHOR]

As the fatigue cracks are initially invisible to the human eye, detecting them can be complicated. Large scale disruption and risk are directly caused by these cracks if not observed early or left unattended. Since the fatigue crack is challenging to locate, routine inspections or the use of ultrasonic instruments are the traditional methods for detection. Therefore, an image processing method enabled with computer vision and deep learning can be used to detect a fatigue crack. Provided there is an image data input, cracks are identified using a convolutional neural network described in this paper. Edge detector and line detection techniques are used to determine the crack's length and crack angle. Finally, the estimated values using the regression process are compared to the analytical values. At first, the values computed using both methods have excellent correlation. A minor variation can be seen at the final stage when the crack is in a transition stage where it is evolving from a stable crack to an unstable crack. [ABSTRACT FROM AUTHOR]

The fast growth of composite materials in the aerospace industry is due to its desired properties over conventional metals. In this paper, a detailed static structural analysis and vibrational analysis was carried out for the aircraft wing frontal spar using hybrid material and it was compared with different conventional materials used in aerospace industry like aluminium, CFRP (Carbon Fiber Reinforced Polymer). The carbon fiber and flax fiber were selected for composition in hybrid composite material since it shows an exceptional specific mechanical properties and good vibration damping properties. The frontal wing spar was designed using modelling software CATIA V5. Static structural analysis and modal analysis was performed using ANSYS software. Exploring the results of structural analysis, it was interpreted that the static structural efficiency of the hybrid composite material was exceptionally high compared to aluminium and it shows nearly equal specific mechanical properties compared to CFRP. This leads to reduction in cost of the structure. From the modal analysis the various natural frequencies for six modes are discussed. The analysis shows natural frequency of wing frontal spar using hybrid composite material exhibits similar deformation compared to CFRP. Hybrid composite material exhibits higher damping factor when compared to chosen materials. This behaviour of hybrid composite material shows that it could be effectively replaced in wing frontal spar instead of conventional materials like CFRP and aluminium. [ABSTRACT FROM AUTHOR]

The purpose of designing a spacecraft Altitude and dynamic control models play an important role in an interplanetary space mission. Particular emphasis is controlling spacecraft Altitude by sail tilting and shifting. In addition, investigate an uncertain balance amongst the centre of pressure and centre of mass on a single axis gimbaled control. Implies a method of Monte Carlo is with standing a significant of solar pressure disturbance torque in deep space mission. A flight test experiment drives in a Low Earth Orbit (LEO), hence, authenticate the source of solar sailing is also suggested. Parameters are incorporating to study and demonstrate the various principals and methods involved in altitude control design and dynamic modeling at LEO. Mitigation of disturbance torques was also examined. [ABSTRACT FROM AUTHOR]

Over the years, application of composite materials has got wider. So there is a necessity for development of new materials to satisfy the environmental requirements. It is viable through the process of hybridization of natural fibers to synthetic fibers. This investigation is carried out to determine the tensile and flexural strength of hybrid composites with various fiber combinations and stacking sequence. Thus it is easy to identify the natural fiber hybrid combination with high mechanical properties under static and varying thermal load conditions. The various fiber materials are meticulously chosen and three conventional and six different hybrid laminates were fabricated with various stacking sequences of selected fibers using hand layup technique. The tensile and flexural properties are determined through mechanical testing and compared with conventional materials. The failure morphologies are captured and investigated with zoom optical cameras. On analyzing the results, it is observed that carbon-flax hybrid composites exhibit nearly equivalent specific strength at a reduced cost compared to the carbon/glass fiber hybrid composites and also the effect of the stacking sequence in mechanical properties is elucidated through this study. Varying thermal load analysis reveals that there is a considerable loss in mechanical properties due to thermal exposure. [ABSTRACT FROM AUTHOR]

A curved composite panel is used in aircraft parts such as wings and engine cowling in order to improve their impact resistance to different types of impact loads. The effect of size reduction in the tensile pre-stress behaviour of low velocity impact on different materials such as glass and glass/carbon hybrid is examined in this paper. The effects of low velocity impact behaviour of two different pre-stressed curved laminates are taken for consideration and examined under impact loading. The objective of this research is to improve the efficiency of curved laminate by changing the hybrid composition such as glass/carbon with varied stacking sequence. The present studies using hybrid composition have shown that the load carrying capacity is higher in convex laminates while the damaged surface area in convex laminates is very less. [ABSTRACT FROM AUTHOR]

This work focuses on the study of variation in behaviour of Glass Fiber Reinforced Epoxy Composite laminate in the presence of healing agent filled microcapsules. Healing capacity was tested for the newly developed laminate with capsules. Two types of microcapsules were made and included in the resin system. One type consists of healing agent and other type consists of curing agent. These capsules were blended in the ratio of 10:3 in the resin system and laminate was fabricated by hand lay-up technique. Initially, the effect of microcapsules on the tensile properties of glass fiber epoxy composites was studied. No conspicuous variation was discerned in the tensile nature. The healing ability of the laminate was checked by producing minor indentation damage on the surface of the laminate with a 0.5 mm ball indenter. It was noticed that 80% of the indentation was recovered within the time span of 48 hours and 93% of healing efficiency was attained. FE analysis was performed with MIDAS NFX software to confirm the results. Both experimental and FE analysis results were observed to be identical. [ABSTRACT FROM AUTHOR]

The intent of this project is to determine the tensile strength of CFRP lap joint with and without introduction of multiwall carbon nano tubes (MWCNT). Specimens with lap joint were prepared by Adhesive bonding. The dimensions of the specimens were kept according to the ASTM standard D-5868. An experimental work along with FEA analysis was undertaken to identify the ultimate tensile strength and modes of failure in two different categories of adhesively bonded specimen, firstly with inclusion of different percentages of MWCNT and secondly without inclusion of MWCNT. MWCNT of 0.1% and 0.3% by weight was added to the adhesive used in creating the joint. The adhesively bonded specimens with inclusion of MWCNT showed better load bearing capacity, the highest being 86% for 0.3% MWCNT. An increment of 27% was observed in the tensile strength with the increase in percentage of MWCNT. Further the FEA analysis was carried out which proved the experimental results are well within the error range of 1%. [ABSTRACT FROM AUTHOR]

The objective of the research is to investigate the fatigue life of intra-ply hybrid Carbon-Aramid laminate with Epoxy resin in on-axis and off-axis directions. Three different off-axis angles of 15°, 30° and 45° were considered for the present work. The intra-ply hybridization is used to combine the superior mechanical properties of Carbon fibre with excellent elongation-to-failure property of Aramid fibre in the same lamina. The fatigue test was performed using load control using a frequency of 5Hz. The fatigue behaviour was studied for Carbon/Epoxy, Aramid/Epoxy, Carbon-Aramid/Epoxy, Carbon-Aramid/Epoxy - 15°, Carbon-Aramid/Epoxy - 30° and Carbon-Aramid/Epoxy - 45° with the stress ratio of R = 0.1. The ultimate tensile strength decreases progressively for Carbon/Epoxy, Carbon-Aramid/Epoxy, Aramid/Epoxy, Carbon-Aramid/Epoxy - 15°, Carbon-Aramid/Epoxy - 30° and Carbon-Aramid/Epoxy - 45°. The effect of off-axis loading indicates that the increase of fibre angle influences the decrease in tensile strength and fatigue life. [ABSTRACT FROM AUTHOR]

In this paper, Acoustic Emission (AE) based damage mode identification of Glass Fibre Reinforced Plastic (GFRP) lap joints is detailed using laboratory scale experiments. Bonded single lap joint specimens are fabricated from GFRP laminates. These specimens are subjected to tensile test with on-line AE monitoring. The study of failure mechanisms is facilitated by the choice of different oriented lap joint specimens in which one or two such mechanisms predominate. Range of peak frequencies in each orientation is investigated using frequency analysis. Fast Fourier Transforms enabled calculating the frequency content of each damage mechanism. Parametric plots are used to discriminate the different stages of occurrence of failure mechanism in lap joints. Results have shown that predominate of failure modes in each orientation is used as a key in the study of discrimination of failure modes from AE data in lap joints. [ABSTRACT FROM AUTHOR]