The Experts below are selected from a list of 12876 Experts worldwide ranked by ideXlab platform

I. Singh - One of the best experts on this subject based on the ideXlab platform.

  • neural network approach for estimating the residual tensile strength after drilling in uni directional glass fiber Reinforced Plastic laminates
    Materials & Design, 2010
    Co-Authors: Roshan Mishra, Jagannath Malik, I. Singh
    Abstract:

    The drilling of fiber Reinforced Plastics (FRP) often results in damage around the drilled hole. The drilling induced damage often serves to impair the long-term performance of the composite products with drilled holes. The present research investigation focuses on developing a predictive model for the residual tensile strength of uni-directional glass fiber Reinforced Plastic (UD-GFRP) laminates with drilled hole which has not been developed worldwide till now. Artificial neural network (ANN) predictive approach has been used. The drill point geometry, the feed rate and the spindle speed have been used as the input variables and the residual tensile strength as the output. The results of the predictive model are in close agreement with the training and the testing data.

  • Drilling of uni-directional glass fiber Reinforced Plastic (UD-GFRP) composite laminates
    The International Journal of Advanced Manufacturing Technology, 2006
    Co-Authors: I. Singh, N. Bhatnagar
    Abstract:

    Drilling of fiber Reinforced Plastic (FRP) composite materials is a field open to a plethora of questions. Drilling-induced damage is a research area that has not been explored exhaustively. The present research endeavor is an effort to correlate drilling-induced damage with drilling parameters. Tool point geometry is considered a major factor that influences drilling-induced damage. Experiments were conducted and drilling-induced damage was quantified using the digital image processing technique. The results also reestablished the cutting speed to feed ratio as an important variable that influences drilling-induced damage. Mathematical models for thrust, torque, and damage are proposed that agree well with the experiments.

  • drilling induced damage in uni directional glass fiber Reinforced Plastic ud gfrp composite laminates
    The International Journal of Advanced Manufacturing Technology, 2006
    Co-Authors: I. Singh, N. Bhatnagar
    Abstract:

    Uni-directional glass fiber Reinforced Plastic (UD-FRP) composite materials are a feasible alternative to structural members that bear loads in only one direction. FRP composite materials have excellent properties in the direction of the fibers. Drilling- induced damage acts as an inhibitor to their application, as the holes act as stress concentration sites for failure under loading. The present study is an attempt to study the influence of drilling-induced damage on the residual tensile strength of uni-directional composite laminates and to propose a mathematical model correlating the residual strength with the drilling parameters. A finite element model (FEM) is also developed to study the drilling-induced damage in composite laminates.

  • damage investigation in drilling of glass fiber Reinforced Plastic composite laminates
    Materials and Manufacturing Processes, 2004
    Co-Authors: Naresh Hatnaga, I. Singh, D Nayak
    Abstract:

    Machining of fiber Reinforced Plastic is a process that is substantially different from metals. The inherent anisotropy in the material system makes the material removal mechanism quite complex. Drilling composite materials is necessary to ascertain the structural integrity of intricate composite products. Drilling of laminated structures results in extensive damage around the drilled hole. This study is an attempt to quantify and propose mathematical models for drilling-induced damage in terms of the cutting speed and the feed speed. Mathematical models have also been proposed for the resulting thrust force and the torque. Four different drill point geometries, namely 4-faceted, 8-faceted, parabolic, and Jodrill, are investigated in this study.

Behzad Mazhari - One of the best experts on this subject based on the ideXlab platform.

  • evaluating long term performance of glass fiber Reinforced Plastic pipes subjected to internal pressure
    Construction and Building Materials, 2016
    Co-Authors: Roham Rafiee, Behzad Mazhari
    Abstract:

    Abstract A computational modeling procedure is developed for simulating long-term creep behavior of Glass Fiber Reinforced Plastic (GFRP) mortar pipes subjected to internal pressure. The modeling procedure includes creep evaluation, stress analysis, failure evaluation and degradation of mechanical properties. Different levels of internal pressure are examined to obtain sufficient data point on failure-pressure versus time-to-failure graph up to 100,000 min. At each specific pressure level, the modeling procedure continues till the functional failure is distinguished implying on weepage phenomenon. Obtained data are extended to 50 years using extrapolation technique for predicting the remaining strength of investigated GFRP pipe after 50 years.

  • simulation of the long term hydrostatic tests on glass fiber Reinforced Plastic pipes
    Composite Structures, 2016
    Co-Authors: Roham Rafiee, Behzad Mazhari
    Abstract:

    Abstract The main objective of this paper is to simulate long-term hydrostatic tests on Glass Fiber Reinforced Plastic (GFRP) pipes. An experimental procedure for obtaining pressure class of GFRP pipes on the basis of long-term behavior is very time consuming and costly that sometimes take about 2 years for collecting required data. Then, obtained results are extrapolated to 50 years. In this work, a theoretical modeling procedure is developed to obtain residual strength of pipes after 50 years taking into account creep phenomenon. Developed progressive modeling consists of creep modeling, stress analysis and failure evaluation. An integrated modeling procedure is developed reporting time-to-failure at any desired internal pressure. As a case study and also validation purpose, the developed modeling procedure is conducted for predicting long-term behavior of a specific GFRP pipe subjected to internal pressure. A comparison between real experimental data and theoretical modeling is presented. A very good agreement between predicted 50-year hydrostatic pressure and experimental data implies on the proficiency of the developed modeling. Since the developed modeling is just in need of short-term experimental data on pure resin, it could be used as an appropriate engineering tool for industrial centers.

A Ramachandra - One of the best experts on this subject based on the ideXlab platform.

  • delamination analysis in drilling process of glass fiber Reinforced Plastic gfrp composite materials
    Journal of Materials Processing Technology, 2007
    Co-Authors: N S Mohan, S M Kulkarni, A Ramachandra
    Abstract:

    Abstract Machining processes are generally used to cut; drill, or contour composite laminates for building products. In fact, drilling is one of the most commonly used manufacturing processes to install fasteners for assembly of laminate composites. The material anisotropy resulting from fiber reinforcement heavily influences the machinability during machining. Machining of fiber Reinforced Plastic (FRP) components is often needed in spite of the fact that most FRP structures can be made to near-net shape and drilling is the most frequently employed secondary machining process for fiber Reinforced materials. Therefore, the precise machining needs to perform to ensure dimensional stability and to obtain a better productivity of the component. The drilling parameters and specimen parameters evaluated were speed, feed rate, drill size and specimen thickness. A series of experiments were conducted using TRIAC VMC CNC machining center to machine the composite laminate specimens at various cutting parameters and material parameters. The measured results of delamination at the entry and exit side of the specimen were measured and analyzed using commercial statistical software MINITAB14. The experimental results indicated that the specimen thickness, feed rate and cutting speed are reckoned to be the most significant factors contributing to the delamination. A signal-to-noise ratio is employed to analyze the influence of various parameters on peel up and push down delamination factor in drilling of glass fibre Reinforced Plastic (GFRP) composite laminates. The main objective of this study is to determine factors and combination of factors that influence the delamination using Taguchi and response surface methodology and to achieve the optimization machining conditions that would result in minimum delamination. From the analysis it is evident that among the all significant parameters, specimen thickness and cutting speed have significant influence on peel up delamination and the specimen thickness and feed have more significant influence on push down delamination. Confirmation experiments were conducted to verify the predicted optimal parameters with the experimental results, good agreement between the predicted and experimental results obtained to be of the order of 99%.

Tsunaji Kitayama - One of the best experts on this subject based on the ideXlab platform.

  • Detection and quantitative evaluation of defects in glass fiber Reinforced Plastic laminates by microwaves
    Composite Structures, 2015
    Co-Authors: Atsushi Hosoi, Yasumoto Sato, Yuhei Yamaguchi, Yang Ju, Tsunaji Kitayama
    Abstract:

    A novel method using microwaves is proposed to detect and evaluate defects in glass fiber Reinforced Plastic (GFRP) laminates. A thin circular Plastic film simulating delamination was inserted in GFRP laminates and was detected using microwave reflectometry. A focusing mirror sensor consisting of a horn antenna and two metal mirrors was used to improve the measurement resolution. In addition, the thickness of the film was calculated using a proposed model based on microwave propagation theory. Measuring the variation in the amplitude of the microwave reflectivity, a 7.5-μm-thick film was successfully detected in a 3-mm-thick GFRP laminate. Moreover, the calculated results of the inserted film thickness had a high degree of accuracy.

Roham Rafiee - One of the best experts on this subject based on the ideXlab platform.

  • evaluating long term performance of glass fiber Reinforced Plastic pipes subjected to internal pressure
    Construction and Building Materials, 2016
    Co-Authors: Roham Rafiee, Behzad Mazhari
    Abstract:

    Abstract A computational modeling procedure is developed for simulating long-term creep behavior of Glass Fiber Reinforced Plastic (GFRP) mortar pipes subjected to internal pressure. The modeling procedure includes creep evaluation, stress analysis, failure evaluation and degradation of mechanical properties. Different levels of internal pressure are examined to obtain sufficient data point on failure-pressure versus time-to-failure graph up to 100,000 min. At each specific pressure level, the modeling procedure continues till the functional failure is distinguished implying on weepage phenomenon. Obtained data are extended to 50 years using extrapolation technique for predicting the remaining strength of investigated GFRP pipe after 50 years.

  • simulation of the long term hydrostatic tests on glass fiber Reinforced Plastic pipes
    Composite Structures, 2016
    Co-Authors: Roham Rafiee, Behzad Mazhari
    Abstract:

    Abstract The main objective of this paper is to simulate long-term hydrostatic tests on Glass Fiber Reinforced Plastic (GFRP) pipes. An experimental procedure for obtaining pressure class of GFRP pipes on the basis of long-term behavior is very time consuming and costly that sometimes take about 2 years for collecting required data. Then, obtained results are extrapolated to 50 years. In this work, a theoretical modeling procedure is developed to obtain residual strength of pipes after 50 years taking into account creep phenomenon. Developed progressive modeling consists of creep modeling, stress analysis and failure evaluation. An integrated modeling procedure is developed reporting time-to-failure at any desired internal pressure. As a case study and also validation purpose, the developed modeling procedure is conducted for predicting long-term behavior of a specific GFRP pipe subjected to internal pressure. A comparison between real experimental data and theoretical modeling is presented. A very good agreement between predicted 50-year hydrostatic pressure and experimental data implies on the proficiency of the developed modeling. Since the developed modeling is just in need of short-term experimental data on pure resin, it could be used as an appropriate engineering tool for industrial centers.