Polypropylene-based composites are widely used in the industrial field, especially in automotive applications, due to their excellent mechanical properties and low cost. This research is directed towards obtaining the optimal values of mechanical properties of long glass fiber-reinforced polypropylene composite (LGFPP) and polymer-layered silicate nanocomposites (PP-OMMT) for different objectives. Though the primary objective was to minimize the cost of the composite, simulations were also performed to obtain specific desired properties of the composite (irrespective of the composite cost). The latter simulation results are useful in designing products where quality of the composite cannot be compromised (while the cost of the composite is secondary). In this study, the properties that were optimized include tensile Young's modulus, flexural Young's modulus, notched I-zod impact, and permeation. Regression models were obtained and used to predict these properties as functions of corresponding compositions of the composites. Further, optimization procedures were simulated using these models along with other constraints and objective functions. All simulations are programmed using MATLAB version 7.10.0 (R2010a).

Polypropylene-based composites are widely used in the industrial field, especially in automotive applications, due to their excellent mechanical properties and low cost. This research is directed towards obtaining the optimal values of mechanical properties of long glass fiber-reinforced polypropylene composite (LGFPP) and polymer-layered silicate nanocomposites (PP-OMMT) for different objectives. Though the primary objective was to minimize the cost of the composite, simulations were also performed to obtain specific desired properties of the composite (irrespective of the composite cost). The latter simulation results are useful in designing products where quality of the composite cannot be compromised (while the cost of the composite is secondary). In this study, the properties that were optimized include tensile Young's modulus, flexural Young's modulus, notched I-zod impact, and permeation. Regression models were obtained and used to predict these properties as functions of corresponding compositions of the composites. Further, optimization procedures were simulated using these models along with other constraints and objective functions. All simulations are programmed using MATLAB version 7.10.0 (R2010a).

Thesis (M.S.)--California Polytechnic State University, 2009. / Mode of access: Internet. Title from PDF title page; viewed on July 17, 2009. Major professor: Dr. Faysal Kolkailah. "Presented to the faculty of California Polytechnic State University, San Luis Obispo." "In partial fulfillment of the requirements for the degree of Master of Science in Aerospace Engineering." "June 2009." Includes bibliographical references (p. 284-287).

In this study, glass and Kevlar® fibers reinforced epoxy composites were manufactured and characterized using different techniques. The effect of thermal exposure on the flexural properties of the composites was investigated to ascertain its suitability for the intended application in cowling panels of light engine aircraft. Thermogravimetric analysis (TGA) was carried out on both reinforced and unreinforced epoxy resin to evaluate their thermal stability at elevated temperatures. Dynamic mechanical thermal analysis was carried out to evaluate the effects of thermal exposure, applied strain and frequency on the dynamic mechanical response of the composites. The effects of the applied resin hardener and thermal exposure on the flexural strength, flexural modulus and dynamic impact response of the composites were also investigated. The flexural properties were determined using 3-point bending test, while the impact test was carried out using Split Hopkinson Pressure Bar (SHPB). TGA analysis of the reinforced and unreinforced epoxy showed no significant weight loss until the test samples were heated above 250°C in an inert atmosphere. Dynamic Mechanical Thermal Analysis (DMTA) on the composites indicated the glass transition temperature to lie between 80 and 100°C. The results of the flexural and impact tests showed that the mechanical integrity of both glass and Kevlar® fiber reinforced epoxy composites remained unimpaired by radiative or convective heat exposure for up to 3 h until the exposure temperature exceeded 200°C. This is much higher than the service temperature of cowling panels of light engine recreational aircrafts. When the manufactured fiber reinforced epoxy composites were exposed to temperature above 200°C matrix degradation occurred, which became very significant when the exposure temperature was higher than 250°C. Extensive delamination and matrix cracking occurred when the composites were exposed to the temperature range 250°C - 300°C for 1 h. Fiber-matrix debonding was not observed in the composite except after failure under impact loading. This is evidence of the fact that the epoxy matrix was adequately wetted by both the glass and Kevlar® fibers resulting in the strong fiber/matrix interfacial bonding. While the Kevlar® reinforced epoxy displayed a better damage tolerance under flexural and impact loading, glass fiber reinforced epoxy showed higher strength but lower damage tolerance. Glass fiber reinforced epoxy also showed more resistance to damage under exposure to thermal flux than Kevlar® reinforced epoxy. Under impact loading, the Kevlar® reinforced composite failed by delamination with no fiber rupture, whereas the glass fiber reinforced epoxy failed by matrix cracking, debonding, fiber rupture and fiber pullout. The results from this research have established the effect of radiative and convective thermal exposure on the mechanical behavior of the fabricated Kevlar® fiber and glass reinforced epoxy composites. The maximum temperature reached on the inner surface of the cowling panels of a typical light engine recreational aircraft due to heat radiations from the engine block has been estimated to be about 65°C. This is lower than the glass transition temperature of the epoxy matrix as obtained from DMTA. The low temperature rise is due to inflow cooling air into the cowling chamber in flight. The results of the current investigations suggest the suitability of composite materials for the intended application. The intensity of thermal exposure, to which the materials will be exposed in such application, may not cause any significant damage to the mechanical integrity of the composite. However, since the difference between the possible exposure temperature and the glass transition temperature is only a little over 20°C, a layer of thermal insulator on the inner surface of the cowling made of fiber reinforced epoxy will be desirable to further sustain the mechanical integrity of the composites when selected for use as choice materials for cowling panels of light engine aircraft.

This work has a design character, deals with the design of machine for grinding fiberglass belts. Contains machine design proces, the individual assemblies and the way the machine works. A part of the solution is creating 3D model of machine.

In an effort to present more ‘green’ material for massive manufacturing that are both competitive in their properties and can be more environmental friendly, natural fibers are being considered for possible applications in the automotive industry. This paper shows an exploratory study of the effects of pressure and layup on a hybrid composite of randomly oriented woven kenaf fibers and fiberglass/polyester sheet molding compound (SMC). In addition to initial testing performed on their water absorption and other important properties, these hybrid composites were tested to determine the bending modulus of elasticity (MOE) and the bending modulus of rupture (MOR) as well as the tensile modulus of elasticity (MOE), ultimate tensile strength. Pictures are taken from a Spectral Electron Microscope to determine if the fiber mats were properly penetrated by the resin and if the structural integrity of the fibers was maintained during manufacture.

THE CRITICAL FLASHOVER (CFO) VOLTAGE OF AN INSULATION STRUCTURE IS COMMONLY USED TO DESCRIBE THE INSULATION STRUCTURE¡¯S LIGHTNING IMPULSE STRENGTH. THE FIBERGLASS DISTRIBUTION POLE WAS RECENTLY INTRODUCED TO POWER DISTRIBUTION SYSTEMS. HOWEVER, VERY LITTLE WORK HAS BEEN DONE ON EITHER THE LIGHTNING IMPULSE CHARACTERISTICS OF DISTRIBUTION LINE STRUCTURES WITH FIBERGLASS POLES OR THE ELECTRICAL DEGRADATION OF FIBERGLASS. THE WORK IN THIS THESIS REPRESENTS THE RESULTS OF A LABORATORY STUDY ON LIGHTNING IMPULSE CHARACTERISTICS OF DISTRIBUTION LINE STRUCTURES WITH FIBERGLASS POLES AND THE ELECTRICAL DEGRADATION OF FIBERGLASS. THE CRITICAL FLASHOVER (CFO) VOLTAGES OF THE FIBERGLASS DISTRIBUTION POLE AS AN INSULATION STRUCTURE ALONE AND ITS COMBINATION WITH VARIOUS INSULATORS WERE EVALUATED. THE ADDED CFO VOLTAGES FROM FIBERGLASS DISTRIBUTION POLES TO BASIC INSULATION COMPONENTS WERE CALCULATED BASED ON THE TEST RESULTS. THE ACCELERATED AGING TESTS AND CORRESPONDING ELECTRICAL EVALUATION TESTS WERE ALSO CONDUCTED TO INVESTIGATE THE ELECTRICAL DEGRADATION OF FIBERGLASS.

The purpose of this study was to determine the effects, if any, of including varying amounts of fiberglass in Unidirectional Carbon Fiber Laminates. The focus was on strength, weight, and damage. A solution to the entrapment of air in thick unidirectional carbon fiber laminates under vacuum pressure was expected from this study. This study presents background, introduction, data, and results pertaining to the subject. Care was made to fully explain all procedures and terminology for complete comprehension of the subject matter. This study used Design of Experiments to formulate an adequate test population, and it used multiple specimens per Case to formulate an accurate representation of the results. This study used empirical results calculated from Compression After Impact data gathered on a Instron model 5585H at NRRI with a CAI frame, and a load cell capable of 56,250lbs, using Bluehill software for data collection, as well as results determined from nondestructive inspection using a PE + Pulse Echo ultrasonic machine, specifically a Flawinspecta from Diagnostic Sonar LTD with 128 element 67mm array and Flawinspecta version 1.3.6 software. A focus of this research was to create a method to manufacture thick unidirectional carbon fiber laminates solely under vacuum pressure. Currently the only way to manufacture suitable thick unidirectional laminates is through use of an autoclave; otherwise an abundance of entrapped air structurally weakens the part and will result in an inadequate specimen. This entrapped air not only weakens the piece by interrupting the stress handling characteristics of the fiber-matrix structure, but makes it near impossible to use ultrasound as a nondestructive inspection option to check for inconsistencies in the material. The second focus of the research was to understand the effects, if any of including fiberglass within a carbon composite panel. Both dry fiberglass veil and pre-preg fiberglass fabric were included in various samples to view any effects on strength, and damage tolerance. The samples were compared on thickness or bulk, weight, residual strength, and damage mitigation. Disclaimer: Certain information such as: Sources, Technical Data, Specific Names, etc. must be withheld due to Classification, and Business Interests.

This research explores the use of carbon/epoxy and fiberglass/epoxy fiber-reinforced polymer (FRP) composite rebar manufactured on a three-dimensional braiding machine for use as reinforcement in concrete beams under four-point bending loads. Multiple tows of prepreg composite fibers were pulled to form a unidirectional core. The core was consolidated with spirally wound Kevlar fibers which were designed to also act as ribs to increase pullout strength. The rebar was cured at 121â—¦C (250â—¦F) in an inline oven while keeping tension on the fibers. Five configurations of reinforcing bars were used in this study as reinforcement in concrete beam specimens: carbon/epoxy rebar and fiberglass/epoxy rebar were manufactured on the three-dimensional braiding machine and cured in an inline oven while still under tension immediately after production; carbon/epoxy rebar was manufactured by IsoTruss industries on the three-dimensional braiding machine and was rolled and stored before curing; fiberglass/epoxy rebar was purchased from American Fiberglass; conventional No. 4 steel rebar was also purchased. All bars were embedded in 152 cm (60 in) long, 11 cm (4.5 in) wide, and 15 cm (6.0 in) tall concrete beams. Beams were tested under four-point bending loads after which three 30 cm (12 in) specimens were taken from the ends of each configuration to be tested under axial compression loads in order to investigate the effects of the concrete voids on the concrete strength. Concrete beams reinforced with BYU glass/epoxy rebar manufactured on the three-dimensional braiding machine exhibited 5% greater compression bending stress and 11% greater tension bending stress than concrete beams reinforced with industry manufactured glass/epoxy rebar. Concrete beams reinforced with BYU carbon/epoxy rebar manufactured on the three-dimensional braiding machine exhibited 18% lower compression bending stress and 64% lower tension bending stress than concrete beams reinforced with industry manufactured carbon/epoxy rebar. BYU glass/epoxy rebar has a 3% greater stiffness and 1% greater displacement than industry manufactured glass/epoxy rebar and BYU carbon/epoxy rebar has a 40% greater bending stiffness and 19% lower displacement than industry carbon/epoxy rebar. BYU carbon/epoxy rebar has 49% lower compression bending stress, 1% lower tension bending stress, 28% lower displacement, and a 68% greater bending stiffness than BYU glass/epoxy rebar. BYU glass/epoxy rebar has 38% greater compression bending stress, 30% lower tension bending stress, 26% greater center displacement, and a 105% lower bending stiffness than conventional steel. BYU carbon/epoxy rebar has 8% lower compression bending stress, 31% lower tension bending stress, and 22% lower bending stiffness than steel. The deflections of steel reinforced concrete and BYU carbon/epoxy reinforced concrete are comparable with steel rebar displaying a 1% greater center displacement than BYU carbon/epoxy rebar.

Although fiberglass reinforced polyester manholes and wetwalls have been proven by the American Society for Testing Materials (ASTM) and are currently being used in some parts of the world, there still exists a lack of investigation for testing manhole covers made with different inorganic fillers under static and dynamic behavior. The filler would not only improve the mechanical properties of fiber-reinforced polymer matrix composite not otherwise achieved by the resin ingredients alone but also lower the overall manufacturing costs by decreasing the amount of fiber content without adversely affecting the composite’s mechanical properties. The main objective involved the development of fiberglass laminated manhole covers with different inorganic fillers and to study the static and dynamic behavior of the material by performing experimental and numerical analysis. The materials used for the composite laminated test specimens consisted of E-glass woven roving fabric, epoxy, and filler. Two types of inorganic fillers were used for this study, calcium carbonate and high-density adhesive fillers. The static/dynamic test results showed that the laminates made with fiberglass and filler experienced lower performance in tensile strength but higher improvement in flexural strength. The modal analysis results showed that laminates with less filler experienced higher modes within the specified frequency range. This was expected since the material property of filler increased the stiffness and damping behavior in the composite material.