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Composite beam type structures fail in the presence of cracks. While in use the crack depth gradually increases, the structural stiffness decreases and as a result the beam becomes weaker than its earlier conditions. At the end, the beam may collapse because of an initial or developed small crack. Hence, identification of the crack and its severity is a challenge for researchers. In the present work, vibration signatures were used to detect the crack position as well as crack depth in a cracked FRP composite beam. Seven types of epoxy-glass fibres bidirectional (woven) composite beams made of 13 layers oriented along 0°, 7.5°, 15°, 22.5°, 30°, 37.5°and 45°with clamp-free end condition were studied. Fibre orientation effects on the FRP composite beam with varying crack location and crack depth were evaluated using analytical, finite element methods and Sugeno-fuzzy approach. The results were obtained and verified by experiments. The outcomes of all the methods were in good agreement. It was concluded that the natural frequency and mode shape in free vibration were largely affected by orientation of fibre and crack location and its depth.

This article aims to analyze the tool vibration, surface roughness, and chip morphology in hard turning of hot work AISI H13 steel under multi-walled carbon nanotubes mixed nanofluid with minimum quantity lubrication. Recently developed new-generation nanocomposite AlTiSiN coating deposited on carbide insert via scalable pulsed power plasma (S3P) strategy is used as cutting tool material. The experiments associated with 30 number of trials are performed by considering various machining parameters that includes cutting speed, nose radius, depth of cut, and feed. In perspective of predictive modeling and multi-response optimization, response surface methodology has been engaged as a means to minimize the tool vibration and surface roughness. At last, with the measured tool life and based on the Gilbert’s machining economic model, a distinctive cost analysis has been implemented to demonstrate the cost-effectiveness of coated carbide tool in hard turning. Statistical analysis confirms that nose radius with 36.65% has the highest contribution for surface roughness and cutting speed with 53.88% has the highest contribution for tool vibration. Increased flank wear and tool vibration are responsible for degradation of machined surface finish. Machining under nanofluid-MQL, chip morphology revealed the production of segmented type serrated saw-toothed chips. At higher cutting speed resulted: (a) obvious shape of saw tooth chip, (b) increase of distance among saw tooth, (c) reduction in chip segmentation frequency, (d) decrease of chip thickness. At optimum combination of process variables ( v = 55 m/min, d = 0.2 mm, r = 1.2 mm, f = 0.07 mm/rev), the life of AlTiSiN coated carbide tool is found to be 42 min under nanofluid-MQL and estimated the total machining cost expenditure per finished part of Rs. 153.52. New-generation AlTiSiN coated carbide tools can be competently and productively utilized for machining of hot work tool steel under ecologically cognizant minimum quantity cooling-lubrication, is the most accepted in industrial applications.

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In this work, a fifth-order shear deformation theory is computed using the layer-wise model to determine non-dimensional fundamental frequencies. The theoretical, experimental, and finite element analysis (FEA) results are compared for a standard isotropic material. Hand layup technique is used to prepare glass fiber reinforced polymer composites (GFRPC) with selective layers filled with graphene and flyash. This technique helps to reduce the fabrication cost as the whole structure is not to be strengthened by the fillers. Six classes of the laminated-composite-plate (LCP) such as outer layer graphenated LCP (O-LCP), core layer graphenated LCP(C-LCP), functionally graded LCP (FG-LCP), LCPs only rich in graphene (G-LCP), LCPs only rich in flyash (F-LCP) along with a neat epoxy-glass LCP (N-LCP) are fabricated. A low-cost frequency measurement module is set-up to measure the fundamental frequency (FF) of the fabricated LCPs. FFs, amplitudes, non-dimensional stress parameters, and central deflection of the LCPs under harmonic load, the buckling strength, and displacements of the LCPs are calculated. It is found that harmonically excited C-LCP and O-LCP have better stability accompanied by lower deflections, followed by G-LCP as compared to other kinds of LCPs. Also, the addition of graphene increases the buckling strength of LCPs, which portrays that the local layer filling is a useful technique to enhance the strength of the LCPs.