Sökning: "Shear band"

Visar resultat 11 - 15 av 27 avhandlingar innehållade orden Shear band.

1. 11. Modeling and experimental characterization of pearlitic rail steels subjected to large biaxial strains

   Författare :Knut Andreas Meyer; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hyperelasto-plasticity; axial-torsion; kinematic hardening; biaxial loading; Pearlitic steel;

   Sammanfattning : Large shear strains develop in the near-surface region under the running band of railway rails. Rolling Contact Fatigue (RCF) cracks often initiate in this region, causing major problems for the railway industry. However, characterization of the constitutive and fatigue behavior of this region is difficult due to the large gradient of properties. LÄS MER

3. 12. Mechanical Properties of Transition Metal Alloys from First-Principles Theory

   Författare :Xiaoqing Li; Levente Vitos; Manuel Richter; KTH; []
   Nyckelord :;

   Sammanfattning : The aim of the thesis is to investigate the alloying effect on the mechanical properties of random alloys using the all-electron exact muffin-tin orbitals methodin combination with the coherent-potential approximation. The second-order elastic constants describe the mechanical properties of materials in the small deformation region, where the stress-strain relations arelinear. LÄS MER

4. 13. Compressive failure of unidirectional NCF composites

   Författare :Dennis Wilhelmsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Aerospace; Fibre misalignment; Compressive failure; NCF composite;

   Sammanfattning : With more people flying every year, new technologies are needed to reduce our impact on the environment. One option is to reduce the energy used in flight by introducing lighter materials such as carbon fibre reinforced polymers (CFRP). LÄS MER

5. 14. Simulation of heat generation in elasto-plastic materials

   Författare :Paul Håkansson; Hållfasthetslära; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The demand for improved models for simulation of mechanical problem is today very great, especially since today's computer capacity makes it possible to simulate large and complicated problems. In some applications, temperature effects and the heat generated from inelastic deformation can not be neglected in order to achieve a good accuracy of the simulation. LÄS MER

7. 15. Analyses of Seismic Wave Conversion in the Crust and Upper Mantle beneath the Baltic Shield

   Författare :Sverker Olsson; Roland Roberts; Hans Thybo; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geophysics; converted waves; Moho; upper mantle; Baltic Shield; tomography; anisotropy; receiver function; Geofysik;

   Sammanfattning : Teleseismic data recorded by broad-band seismic stations in the Swedish National Seismic Network (SNSN) have been used in a suite of studies of seismic wave conversion in order to assess the structure of the crust and upper mantle beneath the Baltic Shield. Signals of seismic waves converted between P and S at seismic discontinuities within the Earth carry information on the velocity contrast at the converting interface, on the depth of conversion and on P and S velocities above this depth. LÄS MER