Search for dissertations about: "Crack development"

Showing result 21 - 25 of 131 swedish dissertations containing the words Crack development.

2. 21. The effect of inelastic deformation on crack loading

   Author : Dimosthenis Floros; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Numerical simulation; Mixed mode; Configurational mechanics; Gradient plasticity;

   Abstract : Rolling contact fatigue (RCF) cracks in rails are among the most detrimental railway track defects, in relation to reliability and cost. The cracks grow in a mixed mode II & III, which in combination with the rotating stress field in the neighborhood of the crack-tip, large plastic deformations on the rail surface, crack face friction due to the compressive stresses from the wheel load and anisotropic crack growth resistance, add to the complexity related to the study of RCF cracks. READ MORE

4. 22. Micro-crack initiation and propagation in fiber reinforced composites

   Author : Andrejs Pupurs; Stephen L. Ogin; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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

5. 23. Dynamic Modelling and Vibration Analysis for Gear Tooth Crack Detection

   Author : Omar D. Mohammed; Robert Randall; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Drift och underhållsteknik; Operation and Maintenance Engineering;

   Abstract : The aim of applying vibration-based condition monitoring in gear systems is to detect the initiation and development of degradation before the occurrence of failure. Eventually, degradation will result in a malfunction of the gearing system, which will affect the availability of the whole system. READ MORE

6. 24. Chloride Induced Corrosion of Steel Bars in Fibre Reinforced Concrete

   Author : Carlos Gil Berrocal; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electrical resistivity; chloride ingress; fibre reinforced concrete; crack width; reinforced concrete durability; chloride-induced corrosion;

   Abstract : Chloride-induced corrosion of reinforcement is the most widespread degradation mechanism affecting the durability of reinforced concrete structures. Macro-cracks provide a preferential path for moisture, oxygen and Cl ions to reach the embedded reinforcement, playing a major role in their total transport. READ MORE

7. 25. Cracking in Reinforced Concrete Structures Due to Imposed Deformations

   Author : Agnes Nagy; Avdelningen för Konstruktionsteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; minimum reinforcement; cracking; softening; shrinkage; cooling; imposed deformations; conversion formula; static E-modulus; damping coefficient; resonance frequency; dynamic E-modulus; constitutive model; thermal stress; hydration process; reinforced concrete structure; early age; crack control; Building construction; Byggnadsteknik;

   Abstract : This thesis is concerned with modeling of the cracking process in reinforced concrete due to imposed deformations. Cracking is investigated both at early ages, during hydration, and at mature age when the final properties of the concrete are reached. READ MORE