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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 66 (1962), S. 769-778 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 201 (1965), S. 27-38 
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Zusammenfassung Bei Ermüdung von Fasern gestattet die Näherung für Extremwerte nicht immer eine adäquate Interpretation der Streuung in den beobachteten Lebenszeiten. Mit der Annahme, daß ein beträchtlicher Teil der Streuung mit geschwindigkeitsbedingten Zufallsprozessen, die in der Initiierung des Sprödigkeitsbruches eine Rolle spielen, verknüpft sind, kann die Lebenszeitverteilung aus dem Ausdruck für die Geschwindigkeit des Sprödbruches in orientierten Polymeren abgeleitet werden. Verschiebungen und Änderungen dieser Verteilungen, wie sie aus Änderungen in den Ermüdungsbedingungen folgen, lassen sich in Übereinstimmung mit dem Experiment darstellen, vorausgesetzt, daß die durch mechanische Wirkung induzierten Strukturänderungen in Betracht gezogen werden.
    Notes: Summary In fatigue of fibers, extreme value approaches do not always offer an adequate interpretation of the scatter encountered in observed lifetimes. Assuming that a considerable part of the scatter is associated with rate-controlling random processes involved in the initiation of brittle fracture, then the lifetime distribution can be derived from the expression for the rate of brittle fracture in oriented polymers. Shifts and changes in these distributions, resulting from changes in fatiguing conditions, are shown to be in agreement with experiment provided that the structural changes induced by mechanical action are taken into consideration.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 11 (1967), S. 925-947 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The applicability of Miner's law of cumulative damage to predict lifetimes in experiments involving complex load histories is examined. Lifetimes estimated by Σ ti/(tb)i = 1 are compared with those calculated by the expression for the time to rupture derived by Prevorsek and Lyons assuming that the time to rupture can be approximated by the time to form an unstable crack. For experiments in which the loading conditions became increasingly severe with time, lifetimes predicted by Miner's law are longer than those calculated from the rate of crack propagation, the opposite being found for experiments in which the loading conditions become decreasingly severe with time. Experimental data on hand are in agreement with these findings. Effects of changes in the structural parameters ρ, E, and ΔF* and of variations in the experimental conditions on the accuracy of the lifetime estimates are discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 22 (1978), S. 3511-3524 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The most important requirement for a hot melt adhesive to perform well in gap-filling applications is the ability to yield or flow under shrinkage tension which develops in the adhesives during cooling, while maintaining a satisfactory bond to the substrate. In addition, such an adhesive must have a high room temperature viscosity and high green strength to effect an acceptable bond before curing. We found that the required combination of properties for the gap-filling applications can be achieved with interpenetrating networks of selected thermoset-thermoplastic polymers. The best results were obtained with systems consisting of an amorphous polyester and an epoxy blend. The properties of these adhesives depend on numerous variables. This study concerns the three composition variables which appeared particularly important in the performance of these adhesives: (1) epoxy-polyester ratio, (2) molecular weight of the epoxy system, and (3) the quality of dispersion.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 26 (1988), S. 326-327 
    ISSN: 0887-6258
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 4 (1966), S. 63-88 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A theory of tensile strength, based on the observation of cracks in specimens strained to breaking, is formulated. The treatment involves the assumption that a crack grows to a critical size by a nucleation process. When this critical size is exceeded the crack becomes unstable and propagates spontaneously to produce rupture. By comparing the predicted and measured strength, one can estimate the magnitude of the stress concentration factor in fibers. An interpretative analysis of experimental data obtained at various strain rates indicates that the resulting changes in tensile strength are due primarily to the changes in modulus.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 25 (1985), S. 804-806 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Dicyanate Semi-Interpenetrating Polymer Networks (semi IPNs) are made by dissolving a thermoplastic in crosslinking dicyanates and then curing the resulting mixture. The semi IPNs produced are strong, with tensile strengths of 10,000 to 12,000 psi, and flexible, with elongations to break of 10 to 17 percent. Dicyanate semi IPNs also have good thermal stability and the softening temperatures of the IPNs are significantly, higher than those of the corresponding thermoplastics.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 34 (1994), S. 141-152 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The ultra-high strength/modulus, extended chain polyethylene fiber (Spectra® fiber) composite has shown great potential as a lightweight armor material with its extraordinary capability of absorbing the kinetic energy of projectiles. But the relatively low melting point of this fiber (∼ 145°C) has caused concerns regarding the effect of temperature rise during the impact/penetration process on the performance as armor material. In this article, an analysis of temperature rise in projectile and the fiber composite during the impact/penetration process is described. Combining the simulation of impact deformation by finite element analysis and the simulation of temperature rise by a finite difference approximation of the related dynamic equations, the temperature rise caused by the projectile/composite interaction was estimated. Results show that there is a significant temperature rise at the projectile/composite interface due to the friction but that the short length of time involved in the process and the low thermal conductivity of Spectra fiber composite keep the temperature rise in a very small region (in the order of 0.001 cm) around the interface during the impact/penetration process. Consequently, the volume that is affected by the temperature rise is very small, in the order of total 0.001 cm3 around the projectile, and this is too small to generate any detectable effect on the armor performance. After the projectile is stopped, however, substantial heating of fiber composite can occur under specific conditions as the result of heat flow from the hot projectile embedded in the composite. This heating of fibers, however, is a postmortem effect and hence inconsequential to the ballistic performance of the composite armor.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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