Sökning: "Polymera konstruktionsmaterial"

Visar resultat 1 - 5 av 75 avhandlingar innehållade orden Polymera konstruktionsmaterial.

  1. 1. Fracture mechanics analysis of damage initiation and evolution in fiber reinforced composites

    Författare :Andrejs Pupurs; Luleå tekniska universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polymera konstruktionsmaterial; Polymeric Composite Materials;

    Sammanfattning : When a unidirectional (UD) fiber reinforced polymer composite is loaded in fiber direction in quasi-static or in a high stress cyclic tension-tension regime, many fiber breaks may occur in random positions already during the load increase in the first cycle. This is because fiber strain to failure in UD composites is lower than the polymer matrix strain to failure. LÄS MER

  2. 2. Numerical analysis of the single fiber fragmentation test including the effect of interfacial friction

    Författare :Enrique Graciani; Luleå tekniska universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polymeric Composite Materials; Polymera konstruktionsmaterial;

    Sammanfattning : A numerical analysis of the single fiber fragmentation test is presented in this thesis. The aim of the numerical study is elucidating the influence of friction in the growth of the debond cracks along the fiber-matrix interface. Two distinct approaches and numerical techniques have been employed in the analysis. LÄS MER

  3. 3. Mechanical properties of flax fibers and their composites

    Författare :Edgars Sparnins; Luleå tekniska universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flax fibers; natural fiber composites; mechanical properties; Time dependent behavior; Polymeric Composite Materials; Polymera konstruktionsmaterial;

    Sammanfattning : Flax fibers, along with a number of other natural fibers, are being considered as an environmentally friendlier alternative of synthetic fibers in fiber-reinforced polymer composites. A common feature of natural fibers is a much higher variability of mechanical properties. LÄS MER

  4. 4. A novel composite material from recycled constituents

    Författare :Magdalena Szpieg; Luleå tekniska universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polymeric Composite Materials; Polymera konstruktionsmaterial;

    Sammanfattning : The increasing industrial use of carbon fibre in e.g. aircraft and wind turbines calls for strategies for their recovery and possible reuse. In additional, tremendous amount of energy is needed to be able to manufacture pristine carbon fibres. LÄS MER

  5. 5. Mechanisms of inelastic behavior of fiber reinforced polymer composites

    Författare :Konstantinos Giannadakis; Luleå tekniska universitet; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polymera konstruktionsmaterial; Polymeric Composite Materials;

    Sammanfattning : In the present thesis, the sources of linear/non-linear viscoelastic and viscoplastic behaviour in polymer composite materials are under study. The significance of this work is related to the nature of all composite materials. All polymer composites tend to indicate a time-dependent behaviour. This behaviour can be either linear or nonlinear. LÄS MER