Search for dissertations about: "Polymera konstruktionsmaterial"

Showing result 1 - 5 of 75 swedish dissertations containing the words Polymera konstruktionsmaterial.

  1. 1. Micro-crack initiation and propagation in fiber reinforced composites

    Author : Andrejs Pupurs; Luleå tekniska universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polymer composites; microdamage; fracture mechanics; FEM modeling; Materials science - Construction materials; Teknisk materialvetenskap - Konstruktionsmaterial; Polymera konstruktionsmaterial; Polymeric Composite Materials;

    Abstract : Predicting micro-damage initiation and evolution is one of the key challenges for safe design of fiber reinforced polymer composites. Micro-scale damage such as, for example, single fiber break may be unnoticeable and negligible during the initial service life of composite, however, with many loading and unloading cycles this initially micro-scale damage may propagate forming macroscopic scale cracks that can significantly reduce the service lifetime or even lead to unforeseen catastrophic failure of the composite structure. READ MORE

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

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

    Abstract : 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. READ MORE

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

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

    Abstract : 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. READ MORE

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

    Author : Edgars Sparnins; Luleå tekniska universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flax fibers; natural fiber composites; mechanical properties; Time dependent behavior; Materials science - Other material science; Teknisk materialvetenskap - Övrig teknisk materialvetenskap; Polymeric Composite Materials; Polymera konstruktionsmaterial;

    Abstract : 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. READ MORE

  5. 5. A novel composite material from recycled constituents

    Author : Magdalena Szpieg; Luleå tekniska universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering mechanics - Mechanical manufacturing; Teknisk mekanik - Mekanisk tillverkningsteknik; Polymera konstruktionsmaterial; Polymeric Composite Materials;

    Abstract : 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. READ MORE