Sökning: "Stiffness degradation"

Visar resultat 1 - 5 av 73 avhandlingar innehållade orden Stiffness degradation.

1. 1. On the small strain stiffness of some Scandinavian clays and impact on deep excavation

   Författare :Tara Wood; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; soft clay; small strain stiffness; degradation; seismic testing; sample quality;

   Sammanfattning : This thesis presents the results of a comprehensive study on the small strain stiffness of several Swedish clays and its tentative effect on the design of retaining structures. A combination of field measurement techniques, seismic dilatometer and surface seismics, are complemented with bender element testing of the retrieved samples. LÄS MER

3. 2. A Damage-Based Interface Model: Application to the Degradation and Failure of a Polycrystalline Microstructure

   Författare :Patrik Cannmo; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; damage; polycrystalline microstructure; degradation; slip and dilatation; interfaces; FE-calculations; viscoplasticity; plasticity; failure;

   Sammanfattning : A constitutive model for material interfaces is presented. The model is based on damage coupled to plastic (or viscoplastic) slip and dilatation, and it is able to describe the successive degradation and failure of an interface. LÄS MER

4. 3. Damage accumulation and stiffness degradation in composite laminates

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

   Sammanfattning : In the presented thesis analytical modeling of elastic properties degradation and modeling of damage evolution in composite laminates is performed. Transverse cracking initiation on a fiber/matrix level is briefly studied by testing model composites and cross-ply laminates. LÄS MER

5. 4. On cyclic accumulation models for degradation of railway foundations

   Författare :Hossein Tahershamsi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Natural soft clay; Global Sensitivity Analysis; Sobol method; Experimental design; Rate-dependent models; Cyclic accumulation models; Cyclic degradation; Uncertainty analysis;

   Sammanfattning : The degradation of railway foundations due to the repeated loading of traffic induces maintenance and safety obligations for the track operator. One major contributor to track degradation is the accelerated settlement rates in soft soils below the track that lead to alignment issues, especially at stiffness transitions. LÄS MER

7. 5. Material recycling of post-consumer flexible polyethylene packaging waste

   Författare :Ezgi Ceren Boz Noyan; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; degradation; polyethylene; melt-compounding; washing; post-consumer flexible packaging waste; mechanical properties; plastics recycling;

   Sammanfattning : The mechanical and thermal properties of recycled post-consumer flexible polyethylene packaging waste was studied, using material collected and sorted on a large-scale from two sources. Unwashed, laboratory-scale washed, industrial-scale washed, and industrial-scale washed and melt-compounded (industrially recycled) materials were used. LÄS MER