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Full-Text Articles in Engineering
Carbon Fibers Recycling From Degraded Prepregs And Mechanical Properties Or Recycled Composite, Monjur Morshed Rabby, Minhazur Rahman, Partha Pratim Das, Vamsee Vadlamudi, Rassel Raihan
Carbon Fibers Recycling From Degraded Prepregs And Mechanical Properties Or Recycled Composite, Monjur Morshed Rabby, Minhazur Rahman, Partha Pratim Das, Vamsee Vadlamudi, Rassel Raihan
Institute of Predictive Performance Methodologies (IPPM-UTARI)
The size of the global composites market is anticipated to grow more than previously. Due to the rapidly rising volume of CFRP production, the waste from this material poses numerous problems and has significantly increased the socio-technological pressure to find sustainable composite recycling solutions. The problem is that recycling the composite part is challenging once its service life has expired. The same problem is true for the raw materials (prepregs) used in composite manufacturing. When the prepreg out-life/shelf-life is over, prepregs are abandoned, resulting in a loss of millions of dollars and an adverse environmental effect. In this study, the …
Artificial Intelligence Assisted Residual Strength And Life Prediction Of Fiber Reinforced Polymer Composites, Partha Pratim Das, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Rassel Raihan
Artificial Intelligence Assisted Residual Strength And Life Prediction Of Fiber Reinforced Polymer Composites, Partha Pratim Das, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Rassel Raihan
Institute of Predictive Performance Methodologies (IPPM-UTARI)
With the increased use of composite materials, researchers have developed many approaches for structural and prognostic health monitoring. Broadband Dielectric Spectroscopy (BbDS)/Impedance Spectroscopy (IS) is a state-of-the-art technology that can be used to identify and monitor the minute changes in damage initiation, accumulation, interactions, and the degree of damage in a composite under static and dynamic loading. This work presents a novel artificial neural network (ANN) framework for fiber-reinforced polymer (FRP) composites under fatigue loading, which incorporates dielectric state variables to predict the life (durability) and residual strength (damage tolerance) from real-time acquired dielectric permittivity of the material. The findings …
Dielectric Analysis To Predict Moisture Absorption In Structural Composites: A Data-Driven Approach, Partha Pratim Das, Monjur Morshed Rabby, Vamsee Vadlamudi, Rassel Raihan
Dielectric Analysis To Predict Moisture Absorption In Structural Composites: A Data-Driven Approach, Partha Pratim Das, Monjur Morshed Rabby, Vamsee Vadlamudi, Rassel Raihan
Institute of Predictive Performance Methodologies (IPPM-UTARI)
Due to continual exposure to moist environment, environmental degradation is a major threat to structural composites throughout their service life. Impedance Spectroscopy (IS)/Broadband Dielectric Spectroscopy (BbDS) is a reliable nondestructive method that has been used in polymer industries for dielectric characterization of material. While moisture absorption causes irreversible changes in the polymer matrix composites, it also alters the electrical properties of the system which is detectable using BbDS. Since the physics that drives the change in electrical characteristics is driven by the modifications imposed by water molecules (whether free or bound), both events can be linked. A dielectric spectrum over …
Moisture Content Prediction In Polymer Composites Using Machine Learning Techniques, Partha Pratim Das, Monjur Morshed Rabby, Vamsee Vadlamudi, Rassel Raihan
Moisture Content Prediction In Polymer Composites Using Machine Learning Techniques, Partha Pratim Das, Monjur Morshed Rabby, Vamsee Vadlamudi, Rassel Raihan
Institute of Predictive Performance Methodologies (IPPM-UTARI)
The principal objective of this study is to employ non-destructive broadband dielectric spectroscopy/impedance spectroscopy and machine learning techniques to estimate the moisture content in FRP composites under hygrothermal aging. Here, classification and regression machine learning models that can accurately predict the current moisture saturation state are developed using the frequency domain dielectric response of the composite, in conjunction with the time domain hygrothermal aging effect. First, to categorize the composites based on the present state of the absorbed moisture supervised classification learning models (i.e., quadratic discriminant analysis (QDA), support vector machine (SVM), and artificial neural network-based multilayer perceptron (MLP) classifier) …
The Effect Of Plasma Treatment On The Cure Behavior Of Out-Of-Life Prepregs And An Investigation Of The Mechanical Properties Of Composite Parts Manufactured From Plasma-Treated Prepregs, Monjur Morshed Rabby, Partha Pratim Das, Minhazur Rahman, Vamsee Vadlamudi, Rassel Raihan
The Effect Of Plasma Treatment On The Cure Behavior Of Out-Of-Life Prepregs And An Investigation Of The Mechanical Properties Of Composite Parts Manufactured From Plasma-Treated Prepregs, Monjur Morshed Rabby, Partha Pratim Das, Minhazur Rahman, Vamsee Vadlamudi, Rassel Raihan
Institute of Predictive Performance Methodologies (IPPM-UTARI)
Many industries, including aircraft, automobiles, and marine, are using prepreg (pre-impregnated fibers and a partially cured polymer matrix) to manufacture composite parts to achieve optimum fiber and resin volume ratio and part repeatability. Since prepregs have a short out oflife (i.e., the maximum storing time allowed at room temperature), they must be stored in refrigerators at low temperatures, which, if not maintained, have an unfavorable influence on the intended quality of the final product. For the present study, glass/epoxy prepregs (expired out-life) were plasmatreated before being used to make the composite part to compensate for the room temperature aging effect. …
Coupled Effects In Dielectric And Thermal Properties Of Polymer Matrix Composite Structures Due To Moisture Absorption, Partha Pratim Das, Monjur Morshed Rabby, Vamsee Vadlamudi, Kenneth Reifsnider, Rassel Raihan
Coupled Effects In Dielectric And Thermal Properties Of Polymer Matrix Composite Structures Due To Moisture Absorption, Partha Pratim Das, Monjur Morshed Rabby, Vamsee Vadlamudi, Kenneth Reifsnider, Rassel Raihan
Institute of Predictive Performance Methodologies (IPPM-UTARI)
Fiber reinforced polymer (FRP) composites are being used in number of fields including aerospace, marine, sports, medical, power sectors, etc. due to their lightweight nature while retaining high mechanical performance in terms of high specific strength, stiffness, and great fatigue properties. However, the applicability of these materials is restricted by their stability up to a certain temperature (i.e. glass transition temperature) and environmental degradation (i.e. moisture, UV light, etc.). Moisture ingression greatly reduces their mechanical properties altering material structure by causing polymer plasticization, chain scission and fiber-polymer interface deterioration. These changes instantaneously affect the thermal properties of the materials which …
Dielectric State Variables As Qualitative Indicators Of Moisture Absorption-Caused Mechanical Property Degradation In Gfrp Composite Structures, Partha Pratim Das, Vamsee Vadlamudi, Rassel Raihan
Dielectric State Variables As Qualitative Indicators Of Moisture Absorption-Caused Mechanical Property Degradation In Gfrp Composite Structures, Partha Pratim Das, Vamsee Vadlamudi, Rassel Raihan
Institute of Predictive Performance Methodologies (IPPM-UTARI)
Fiber reinforced polymer (FRP) composites are being used in numerous fields owing to their intrinsic strength to weight ratio and various design benefits. However, these materials are prone to environmental aging, particularly moisture absorption. In essence, absorbed moisture infiltrates the polymer matrix and induces changes in the polymer network through chain scission, plasticization, and other bonding interactions. This causes irreversible damages to the material and significantly decreases mechanical strength. In this study, Broadband Dielectric Spectroscopy (BbDS) has been used to identify the absorption mechanisms in glass fiber reinforced polymer (GFRP) composites by detecting the related polarization mechanisms. Here, results show …
Stiffness Degradation In Fatigue Life Of Composites Using Dielectric State Variables, Muthu Ram Prabhu Elenchezhian, Partha Pratim Das, Minhazur Rahman, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider
Stiffness Degradation In Fatigue Life Of Composites Using Dielectric State Variables, Muthu Ram Prabhu Elenchezhian, Partha Pratim Das, Minhazur Rahman, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider
Institute of Predictive Performance Methodologies (IPPM-UTARI)
Composite materials are widely used in aerospace and automotive structures for decades and over the years the community has gained a better understanding of the damage and failure modes of composites under fatigue. In this article, a dielectric characterization methodology for in-situ monitoring of composites under fatigue environments is proposed. A novel method of measuring the dielectric state variables in Broadband Dielectric Spectroscopy (BbDS) using Extremely Conductive Silver Epoxy Adhesive (ECSEA) paste is presented. These dielectric state variables serve to identify the precursor of the beginning of the end of life of the composite material under fatigue loading. The reliability …
The Effect Of Room-Temperature Aging On Enthalpy And Dielectric Property Of Carbon-Fiber/Epoxy Composite Prepreg And The Mechanical Property Of Manufactured Composite, Monjur Morshed Rabby, Minhazur Rahman, Partha Pratim Das, Muthu Ram Prabhu Elenchezhian, Relebohile George Qhobosheane, Vamsee Vadlamudi
The Effect Of Room-Temperature Aging On Enthalpy And Dielectric Property Of Carbon-Fiber/Epoxy Composite Prepreg And The Mechanical Property Of Manufactured Composite, Monjur Morshed Rabby, Minhazur Rahman, Partha Pratim Das, Muthu Ram Prabhu Elenchezhian, Relebohile George Qhobosheane, Vamsee Vadlamudi
Institute of Predictive Performance Methodologies (IPPM-UTARI)
Fiber-based reinforced plastics are widely used materials in different industries - e.g., Automotive, Aerospace, Defense- because of their various advantages. The most reliable raw materials for manufacturing fiber-based composites are pre-impregnated reinforcing fiber (prepreg). However, the limitation of using prepreg lies in its instability at room temperature. Prepregs have a specific out-life which sometimes makes the manufacturing process difficult. The objective of this study is to find out a way to investigate the room temperature aging effect on prepreg by analyzing the enthalpy and dielectric properties. In this study, differential scanning calorimetry (DSC) was used to measure the reaction enthalpy …
Assessment Of Material State For Predicting The Durability Of Composites, Vamsee Vadlamudi, Muthu Ram Prabhu Elenchezhian, Partha Pratim Das, Rassel Raihan, Kenneth Reifsnider
Assessment Of Material State For Predicting The Durability Of Composites, Vamsee Vadlamudi, Muthu Ram Prabhu Elenchezhian, Partha Pratim Das, Rassel Raihan, Kenneth Reifsnider
Institute of Predictive Performance Methodologies (IPPM-UTARI)
The long term behavior of composites have been extensively studied for the last four decades. Given the heterogeneity of these materials, the damage accumulation mechanisms lead to superior fatigue performance of composites compared to metals. However, due to the ‘sudden death’ behavior controlled by defect coupling, the precursor to fracture plane development of these materials, the challenge remains on how to assess the real-time material state and predict when it becomes critical? In the recent past, broadband dielectric spectroscopy (BbDS) has been used successfully to assess the material state and predict the material state change (triggered by defect coupling) for …
Detection And Prediction Of Defects In Composite Materials Using Di-Electric Characterization And Neural Networks, Muthu Ram Prabhu Elenchezhian, Aishwarya Nandini, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider
Detection And Prediction Of Defects In Composite Materials Using Di-Electric Characterization And Neural Networks, Muthu Ram Prabhu Elenchezhian, Aishwarya Nandini, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider
Institute of Predictive Performance Methodologies (IPPM-UTARI)
The state of art non-destructive inspection techniques for composite materials detect the presence of defects in the composite material, but they do not identify what type of defect it is, and hence, further visual inspection of the details are needed. This visual classification is a costly and time-consuming process, and it’s difficult to distinguish all of the defects effectively. Broadband Dielectric Spectroscopy (BbDS), has been an established tool for dielectric material characterization in polymer industries for a long time. Dielectric spectra of heterogeneous materials are altered by constituent interfaces, with changes in morphological heterogeneity, electrical and structural interactions between particles, …
Dielectric Property Investigation Of Degraded Pre-Preg And Performance Prediction Of The Final Composite Part, Aishwarya Nandini, Nina Shute, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider
Dielectric Property Investigation Of Degraded Pre-Preg And Performance Prediction Of The Final Composite Part, Aishwarya Nandini, Nina Shute, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider
Institute of Predictive Performance Methodologies (IPPM-UTARI)
In recent years, fiber-reinforced (i.e., Glass, Carbon, Kevlar) epoxy composites are used widely in structural applications ranging from military and civil aircraft production to recreational consumer products. Most of the industries use pre-impregnated varieties of composite (prepregs) to make high-quality composite parts. Despite their various advantages, prepreg materials are unstable at ambient temperature. A realistic estimation of the shelf life of prepreg is therefore essential for maintaining quality while reducing wastage of resources. Prepregs are temperature and moisture sensitive material systems. To achieve prolonged shelf life, manufacturer and seller of the prepreg must store the materials at zero degrees Celsius …
Study Of Defect Coalescence In Heterogeneous Material Systems Using Broad Band Dielectric Spectroscopy., Vamsee Vadlamudi, Muthu Ram Prabhu Elenchezhian, Priyanshu Kumar Banerjee, Rassel Raihan, Kenneth Reifsnider
Study Of Defect Coalescence In Heterogeneous Material Systems Using Broad Band Dielectric Spectroscopy., Vamsee Vadlamudi, Muthu Ram Prabhu Elenchezhian, Priyanshu Kumar Banerjee, Rassel Raihan, Kenneth Reifsnider
Institute of Predictive Performance Methodologies (IPPM-UTARI)
Composite materials are essential for many modern applications, including airplanes and cars, energy conversion and storage devices, medical prosthetics, and civil structures. Detecting the initiation, growth, accumulation, and coalescence of micro-damage in these heterogeneous materials and predicting the onset of component failure using conformal Broadband Dielectric Spectroscopy (BbDS) is a promising area of ongoing research. Recently, the authors have developed the critical path concept and Heterogeneous fracture mechanics concept that depicts the effect of defect nucleation, growth, coalescence, and fracture plane development and correlation of these damage mechanisms to change in dielectric response respectively. Current research applies those concepts to …
Predicting Adhesive Bond Performance Based On Initial Dielectric Properties, Priyanshu Kumar Banerjee, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider
Predicting Adhesive Bond Performance Based On Initial Dielectric Properties, Priyanshu Kumar Banerjee, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider
Institute of Predictive Performance Methodologies (IPPM-UTARI)
This paper will focus on an approach to study the mechanical as well as the dielectric properties of an adhesive bond. The dielectric testing is done by using Broadband Dielectric Spectroscopy (BbDS), wherein the dielectric characteristics of the material are analyzed in a wide frequency spectrum. The data obtained by this technique are used to demonstrate the charge transport, the combined dipolar fluctuation, and the effects of polarization occurring between the boundaries of materials. The continuous modifications of the dielectric spectra are due to the changes in the electrical and structural interactions between the particles, shapes, and orientations of the …
Quality Assessment Of Adhesive Bond Based On Dielectric Properties, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Priyanshu Kumar Banerjee, Chaitanya Dave, Anik Mahmood, Rassel Raihan
Quality Assessment Of Adhesive Bond Based On Dielectric Properties, Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Priyanshu Kumar Banerjee, Chaitanya Dave, Anik Mahmood, Rassel Raihan
Institute of Predictive Performance Methodologies (IPPM-UTARI)
Composite materials are widely used in Aerospace, Marine and Automotive structures to reduce weight and increase performance. Adhesive bonding improves the stress distribution between the composite materials / dissimilar materials and ensures a lighter structure than conventional fastener joints. But still there is not much research on the Non-Destructive strength estimation and life prediction, or the damage prognosis of the adhesive bond. One of the main problems when using adhesive bonding is a "kissing bond" which is a weak adhesion bond alternatively called zero volume disbond. Typically, convectional non-destructive methods cannot detect this kissing bond. Broadband Dielectric Spectroscopy, BbDS, is …
Heterogeneous Fracture Mechanics Representations Of The Effects Of Defects From Manufacturing To End Of Life, Vamsee Vadlamudi, Kenneth Reifsnider, Rassel Raihan, Fazle Rabbi
Heterogeneous Fracture Mechanics Representations Of The Effects Of Defects From Manufacturing To End Of Life, Vamsee Vadlamudi, Kenneth Reifsnider, Rassel Raihan, Fazle Rabbi
Institute of Predictive Performance Methodologies (IPPM-UTARI)
Composite materials are essential for many modern applications, including airplanes and cars, energy conversion and storage devices, medical prosthetics, and civil structures. The strength and life of such materials are determined by a complex sequence of progressive nucleation, accumulation, and coalescence of micro-damage that is always related to the micro-morphology of the constituents and their properties. Although detecting and modeling all of the discrete events in that sequence is quite difficult, and in some cases not feasible, it would be very useful to identify observable parameters that indicate the onset of different stages of damage development so that remaining strength …
Performance And Strength Prediction Of Composite Materials Based On Dielectric Property Investigation, Rassel Raihan, Vamsee Vadlamudi, Fazle Rabbi, Kenneth Reifsnider
Performance And Strength Prediction Of Composite Materials Based On Dielectric Property Investigation, Rassel Raihan, Vamsee Vadlamudi, Fazle Rabbi, Kenneth Reifsnider
Institute of Predictive Performance Methodologies (IPPM-UTARI)
Composite materials have significant advantages over more traditional materials and now these material systems are widely used in many advance application, i.e., aerospace, microelectronics, energy storage. In the last few decades, researchers have been doing extensive research on the prediction of the performance and durability of these complex materials systems. The present paper discusses the relationship between the mechanical properties and their characteristics, especially the strength, life, and durability of composite materials and their dielectric response. Essentially all Composite materials are heterogeneous dielectric material systems, i.e., their response to a time-variable electric field is not linear, and is generally dependent …
Dielectric Assessment Of Composite Damage States, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider
Dielectric Assessment Of Composite Damage States, Vamsee Vadlamudi, Rassel Raihan, Kenneth Reifsnider
Institute of Predictive Performance Methodologies (IPPM-UTARI)
The long-term properties of continuous fiber reinforced composite materials are increasingly important as applications in airplanes, cars, and other safety critical structures are growing rapidly. Performance of composite materials is altered by the initiation, accumulation, and interaction of discrete micro-fracture events. Detecting eventual damage growth and predicting the onset of component failure is a challenging task. While a strong foundation of understanding has been established for damage initiation and accumulation during the life of composite materials and structures, an understanding of the nature and details that define fracture path development at the end of life has not been established. In …