Sökning: "crack initiation"

Visar resultat 1 - 5 av 147 avhandlingar innehållade orden crack initiation.

1. 1. Rolling Contact Fatigue of Railway Rails with Emphasis on Crack Initiation

   Författare :Jonas Ringsberg; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; variable amplitude; crack closure; rolling contact fatigue; crack propagation; railway rails; damage accumulation; critical plane approach; crack initiation; plasticity; multiaxial fatigue;

   Sammanfattning : Increased traffic density and the heavier axle loads of modern trains have led to severe problems with rolling contact fatigue (RCF) which cause initiation of surface cracks in railheads. In this thesis, a specific type of surface crack, the head check, is studied numerically with emphasis on fatigue crack initiation. LÄS MER

3. 2. Crack Initiation in Nodular cast Iron

   Författare :Marie Mörtsell; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nodualr cast iron; fatigue; mechanical properties; crack initiation;

   Sammanfattning : .... LÄS MER

4. 3. Initiation and early crack growth in VHCF of stainless steels : Experimental and theoretical analysis

   Författare :Muhammad Waqas Tofique; Jens Bergstöm; Nils Hallbäck; Thierry Pallin-Luc; Karlstads universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Very High Cycle Fatigue; Stainless steel; Ultrasonic fatigue testing; Crack initiation; Crystallographic crack growth; Distributed Dislocation Dipole Technique; Closed cracks; Materialteknik; Materials Engineering;

   Sammanfattning : Mechanical fatigue is a failure phenomenon that occurs due to repeated application of mechanical loads. Very High Cycle Fatigue (VHCF) is considered as the domain of fatigue life greater than 10 million load cycles. LÄS MER

5. 4. On initiation of chemically assisted crack growth and crack propagation paths of branching cracks in polycarbonate

   Författare :Ulf Hejman; Malmö högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; stress corrosion; crack initiation; multiple cracking; polycarbonate; three point bending; stress corrosion cracking; polycarbonate; dissolution; branching; experiment; finite element modelling; stress corrosion; crack initiation; multiple cracking; polycarbonate; three point bending; branching.;

   Sammanfattning : Stress corrosion, SC, in some cases gives rise to stress corrosion cracking, SCC, which differs from purely stress intensity driven cracks in many aspects. They initiate and grow under the influence of an aggressive environment in a stressed substrate. They grow at low load and may branch. LÄS MER

7. 5. Fatigue of Spot Welded Joints: Experiments and Life Predictions

   Författare :Hans-Fredrik Henrysson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; crack closure; crack propagation; crack initiation; finite element method; damage accumulation; variable amplitude; fracture mechanics; fatigue; spot welds;

   Sammanfattning : Methods to assess the fatigue strength of spot welds in built-up structures are used on a daily basis in the automotive industry. Efficient and reliable numerical methods make it possible to achieve designs with low weight, low manufacturing costs and good durability within short development cycles, since the number of prototypes built can be reduced. LÄS MER