EVALUATION OF THRUST FORCE IN DRILLING OF BD-CFRP COMPOSITE USING TAGUCHI ANALYSIS, RESPONSE SURFACE METHODOLOGY AND NEURAL NETWORK

Drilling is the most frequently used machining operation in carbon fiber reinforced polymer (CFRP) composite materials. The quality of the drilled holes is significantly affected by the thrust force generated during drilling of CFRP composite materials. In the present work, an attempt has been made to study the effects of process parameters such as feed rate, spindle speed, drill diameter and point angle on thrust force in drilling of bi-directional carbon fiber reinforced polymer (BD-CFRP) composite laminate using Taguchi design of experiments (DOE), the response surface methodology (RSM) and the genetic algorithm optimized radial basis function neural network (GA-RBFNN). The analysis of variance (ANOVA) is also performed for investigating the influence of process parameters on machining process using high speed steel (HSS) drills. The results reveal that the drill diameter is the most significant design factor influencing the thrust force followed by the spindle speed. It is evident from the investigation that the experimental results of the thrust force in drilling of BD-CFRP composite laminate are in good agreement with the predicted results as per RSM and GA-RBFNN

Carotid Stenting in a Nonagenarian Patient

Carotid artery stenosis is a disabling disease in all age groups. Elderly people are more prone to recurrent strokes due to advancing age and multiple co-morbidities. Treatment options for symptomatic carotid stenosis in the very elderly are the same as in younger patients although with a higher operative risk. We describe a successful case of carotid artery stenting in a nonagenarian with symptomatic carotid artery stenosis, a subgroup for whom treatment options are rarely discussed in guidelines

An integrated experimental and analytical approach on mechanical characterization of advanced powder metallurgy aluminium metal matrix composites reinforced with different particulates

Over the last few decades, ‘Discontinuously Reinforced Particulate Composites (DRPCs)’ are a popular class of composite materials with considerable challenge in processing, characterization and machinability because of their increased strength-weight ratio, stiffness, specific strength and oxidization when compared to various metals and their alloys. This paper discusses experimental and numerical investigation on mechanical characteristics of aluminum metal matrix reinforced with various reinforcement particulates such as silicon carbide, aluminium oxide, and zirconium oxide, compaction pressure (kN) and hold time (s) based on Design of Experiments (DOE) and Finite Element Analysis. Initially this paper discusses the process optimization of Aluminum Matrix reinforced with different particulates experimentally to identify the favourable processing conditions by varying reinforcement materials, compaction pressure (kN) and hold time (s) based on TDOE (Taguchi’s Design of Experiments). Further, this paper concentrates to determine ‘maximum principal stress, equivalent elastic strain and equivalent (von-mises) stress’ based on Finite Element Analysis (ANSYS Workbench-2023R1). The results of the experimentation showed that the highest hardness values were achieved with ZrO _2 reinforcement material. Increasing the compaction pressure from 8 to 12 kN resulted in a slight decrease in surface roughness and porosity. Higher compaction pressures have assumed to facilitate better particle distribution and improved interfacial bonding, leading to smoother surfaces and lower void content. The simulation results showed that the maximum principal stress achieved were (2235.8 MPa) SiC, (3444.4 MPa) Al _2 O _3 , and (3582.5 MPa) ZrO _2 . The equivalent elastic strain achieved was (0.2488) SiC, (0.2421) Al _2 O _3 and (0.262) ZrO _2 . The equivalent (Von Mises) stress achieved was (28751 MPa) for SiC, (24880 MPa) for ZrO _2 and (26972 MPa) for Al _2 O _3 . This experimentation and simulation demonstrated that the PM process can be used to fabricate DRAMMC with different reinforcement particulates. The understanding gained experimentally and analytically from this research can be applied for future processing of Aluminum Matrix Reinforced with different particulates

Taguchi based fuzzy logic model for optimisation and prediction of surface roughness during AWJM of DRCUFP composites

From last two decades, plant fiber reinforced polymer/polyester composites have been effectively used in structural and automotive applications. Researchers and manufacturers are looking forward for an effective utilization of these composites. However, despite the outstanding properties in terms of load bearing capacity and environmental sustainability of plant fibers the uptake of these composites are limited due to its poor machinability characteristics. Hence in this paper, Taguchi based fuzzy logic model for the optimization and prediction of process output variable such as surface roughness during Abrasive Water Jet Machining (AWJM) of new class of plant fiber reinforced polyester composites i.e., Discontinuously Reinforced Caryota Urens Fiber Polyester (DRCUFP) composites has been explored. Initially machining experiments has been carried out using L27 orthogonal array obtained from Taguchi Design of Experiments (TDOE). Finally, Taguchi based fuzzy logic model has been developed for optimisation and prediction of surface roughness. From the extensive experimentation using TDOE it was observed that the optimum cutting conditions for obtaining minimum surface roughness value, water pressure (A): 300 bar, traverse speed (B): 50 mm, stand of distance: 1 mm, abrasive flow rate: 12 g/s, depth of cut (C): 5 mm and Abrasive Size:200 microns. Further from FLM, it is observed that minimum water pressure (A): 100 bar, traverse speed (B): 50 mm, stand of distance: 1 mm, abrasive flow rate: 8 g/s, depth of cut (C): 5 mm and abrasive size:100 microns gave higher surface roughness values (3.47 microns) than that at maximum water pressure (A): 300 bar, traverse speed (B): 150 mm, stand of distance: 4 mm, abrasive flow rate: 12 g/s, depth of cut (C): 15 mm and abrasive size:200 microns the surface roughness values (3.25 microns)

Characterization of Physical and Mechanical Properties of Rice Straw Particles and Furcraea foetida Fiber Reinforced Hybrid Composite

The biodegradable characteristics and abundant availability of the fiber sources have gained the attention of various industries to produce natural fiber-based composites. As a sustainable alternative to the non-biodegradable fiber-based products, the natural composites provide a viable solution to reduce the environmental pollution caused by synthetic materials. This study developed rice straw particle (RSp) and Furcraea foetida (FF) fiber reinforced hybrid composite and investigated its physical and mechanical properties. The addition of 15 wt.% of RSp reduced the density of the test samples by 41.87% and its water absorption (WA) increased with the increase in fiber concentration. The composite with 5 wt.% and 15 wt.% of RSp showed maximum tensile strength (σt: 29.45 MPa) and modulus (σtm: 3.67 GPa), respectively. At 15 wt.% of RSp, the maximum flexural strength (σf: 43.12 MPa) and modulus (σfm: 2.09 GPa) was achieved and at 10 wt.% of RSp showed the highest impact strength (σi: 101.01 J/m). The σt (40.21%) and σf (7.76%) of the RSp reinforced composite were improved by the hybridization of FF (20 wt.%) fiber reinforcement

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Not AvailableAn experiment was carried out to study the correlation and path analysis in six accessions of Saraca asoca at ICAR-Indian Institute of Horticultural Research, Bangalore during 2016-17. Correlation study revealed that the various parameters such as plant height, leaf length, leaf width, leaf area, pod length, pod width, number of pods per plant, number of seeds per pod, seed length and seed width had high significant positive correlation with seed yield per plant. As per the results obtained from path analysis, the plant height, leaf length, leaf width, pod length and number of pods per plant had high positive direct effects on yield per plant. Leaf area, pod width, number of seeds per pod, seed length and seed width had negative direct effects on yield. Thus based on correlation and path analysis, the traits viz., leaf length, leaf width, pod length and number of pods per plant may be considered as selection indices for selecting high yielding accession(s) of S. asocaNot Availabl

DOE coupled MLP-ANN for optimization of thrust force and torque during drilling of CCFRP composite laminates

AbstractAdvancements in technology and the compulsion to use environment-friendly materials have been challenging tasks for researchers for the past two decades. Researchers have been focusing on the utilization of plant fibers to produce good quality fiber-reinforced polymer/polyester composites for automobile, structural, and building applications. Researchers have been looking for high-quality and cost-effective drilling processes. The primary goal of this study is to identify optimal drilling conditions for CCFRP composite laminates, affecting thrust force and torque. This is achieved by manipulating drilling process variables using Taguchi’s Design of Experiments (TDOE), Analysis of variance (ANOVA), Response Surface Methodology (RSM), Desirability Function Analysis (DFA) and Artificial Neural Network (ANN). From the results, it was observed that the spindle speed of 2000 rpm, feed of 15 mm/min, point angle of 90°, fiber length of 6 mm, fiber volume of 30%, and fiber diameter of 7 microns gave the optimum results for obtaining minimum thrust force and torque. Further RSM revealed that an increase in fiber vol % and a decrease in spindle speed resulted in an increase in thrust force and torque. From DFA optimization results, the minimum thrust force of 24.0042 N and minimum torque of 0.8001 N-m was obtained. Finally, the experimental values of thrust force and torque were compared with the corresponding values predicted by the MLP-ANN model. The average error percentage for thrust force and torque was 1.75% and 6.56% respectively

Influence of Chemical Treatments on the Physical and Mechanical Properties of Furcraea Foetida Fiber for Polymer Reinforcement Applications

The usage of natural fibers is regarded as the most viable solution for controlling the consumption of synthetic materials. However, the low moisture resistance, stiffness and poor adhesion capabilities restrict their use in several advanced composite applications. Hence, different surface treatments are employed to improve the physical characteristics of natural materials. In this study, the effect of chemical treatments (sodium hydroxide, acetic acid, potassium permanganate and bromodecane) on the surface characteristics and the adhesion capabilities of Furcraea foetida (FF) fiber with epoxy material is evaluated. From the study, it is seen that the chemical treatment (CT) eliminates the O-H functional groups and enhances the hydrophobic characteristics in FF fiber. Furthermore, the CT removes the amorphous organic attachments and improves the crystallinity in the fiber. However, no substantial increase in the thermal stability of FF fiber was observed post chemical treatment. The microscopic analysis of chemically treated FF (CTFF) fiber shows the elimination of organic attachments and developed neat uniform surface structure. The NaOH-treated FF fiber exhibited maximum tensile strength (σt: 241.75 MPa). Whereas the acetic acid-treated FF fiber showed maximum tensile modulus (σm: 6.9 GPa) and interfacial shear strength (IFSS: 0.06 MPa) compared to CTFF and untreated FF fiber (UTFF)

Processing and Mechanical Characterisation of Titanium Metal Matrix Composites: A Literature Review

Today, Discontinuously Reinforced Particulate Titanium Matrix Composites (DRPTMCs) have been the most popular and challenging in consideration with development and heat treatment due to their significant weight-saving capacity, high specific strength, stiffness and oxidising nature compared with other metals and alloys. Owing to their excellent capabilities, DRPTMCs are widely used in aerospace, automobiles, biomedical and other industries. However, regardless of the reinforcements, such as continuous fibres or discontinuous particulates, the unique properties of DRPTMCs have dealt with these composites for widespread research and progress around the domain. Even though DRPTMCs are one of the most studied materials, expedient information about their properties, processing, characterisation and heat treatment is still scattered in the literature. Hence, this paper focuses on a literature review that covers important research work that has led to advances in DRPTMCs material systems. Further, this paper also deals with broad details about the particulates, manufacturing processes and heat treatment processes