Sökning: "strain rate effects"

Visar resultat 1 - 5 av 138 avhandlingar innehållade orden strain rate effects.

1. 1. Monotonic and Cyclic Plastic Deformation of High-Strength Aluminium Alloys

   Författare :Magnus Hörnqvist Colliander; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strain rate effects; Heat treatment; Dynamic strain ageing; Precipitation hardening; Low cycle fatigue; AA7030; Plastic deformation; Temperature effects; EN AW-7030; Al-Zn-Mg; Strain hardening; Mechanical properties; Dynamic precipitation.;

   Sammanfattning : Dynamic strain ageing (DSA) and dynamic precipitation (DP) are two, closely interrelated, phenomena arising from the dynamic interaction between mobile solute atoms and dislocations. The occurrence of DSA and DP is confined to specific ranges of strain rate and temperature, and aluminium alloys are generally prone to experience DSA and DP already at ambient temperatures and conventional strainrates. LÄS MER

3. 2. Aspects on ventilation induced stress and strain on regional and global inflammation in experimental acute respiratory distress syndrome

   Författare :Jaime Retamal Montes; Anders Larsson; Göran Hedenstierna; Alejandro Bruhn; Björn Jonson; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; ARDS; VILI; respiratory rate; strain; PET;

   Sammanfattning : Mechanical ventilation (MV) is a life-saving therapy in acute respiratory distress syndrome (ARDS), a condition that affects 3000 patients/year in Sweden with a mortality rate of about 40%. However, MV may induce or worsen lung injury causing “ventilator-induced lung injury (VILI)”. LÄS MER

4. 3. The Plastic Flow Behaviour of Aluminium Alloys Exhibiting Dynamic Strain Ageing

   Författare :Magnus Hörnqvist Colliander; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Al-Zn-Mg; Dynamic strain ageing; Strain rate sensitivity; Portevin-Le Chatelier effect; Temperature sensitivity; Thermal activation;

   Sammanfattning : The phenomenon known as dynamic strain ageing, abbreviated DSA, has been known since the beginning of last century. It was first discovered as serrations in the load-elongation curve obtained upon deforming specimens of certain alloys in tension. This phenomenon became known as the Portevin-Le Chatelier (PLC) effect. LÄS MER

5. 4. An Experimental Study of Reynolds Stress Closures in Shear Free and Weakly Sheared Turbulence

   Författare :Dag Aronson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; turbulence modelling; dissipation measurements; Reynolds stress closures; isotropic turbulence; anisotropic dissipation rate tensor; hot-wire anemometry; wall proximity effects; pressure strain rate correlations;

   Sammanfattning : The objective of this thesis work is to obtain data enabling evaluation of closure hypotheses used in the Reynolds stress transport (RST) equations. Special attention has been devoted to studies of flow fields with shear free and weakly sheared turbulence. LÄS MER

7. 5. Concrete Structures Subjected to Fragment Impacts

   Författare :Joosef Leppänen; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; perforation; penetration; strain rate; scabbing; dynamic loading; fragment and projectile impacts; numerical simulations; spalling; concrete; blast wave;

   Sammanfattning : As concrete is commonly used for protective structures, how a blast wave and fragment impacts from an explosion affect the concrete is an important issue. Concrete subjected to explosive loading responds very differently from statically loaded structures. LÄS MER