Sökning: "rate dependent"

Visar resultat 1 - 5 av 1189 avhandlingar innehållade orden rate dependent.

1. 1. Strain rate dependent material model for polymer composites

   Författare :Vivekendra Singh; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; strain rate; finite element; viscoelasticity; viscoplasticity; continuum damage; unidirectional composites;

   Sammanfattning : We propose a micromechanical model that is able to predict the nonlinear behaviour and failure of unidirectional fibre reinforced polymer composites subjected to dynamic loading conditions. This novel material model is heterogeneous on the micro level and homogeneous on the ply level. LÄS MER

3. 2. Speciation and Metabolic rate : Insights from an avian hybrid zone

   Författare :S. Eryn McFarlane; Anna Qvarnström; Jenny Boughman; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; resting metabolic rate; life history; hybridization; speciation; reproductive isolation; Ficedula flycatcher; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology;

   Sammanfattning : The role of divergent climate adaptation in speciation has received surprisingly little scientific attention. My dissertation research focused on how resting metabolic rate (RMR) relates to the build up of prezygotic and postzygotic isolation in a natural Ficedula flycatcher hybrid zone. LÄS MER

4. 3. Time-dependent relaxation of charge and energy in electronic nanosystems

   Författare :Jens Schulenborg; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; heat current; quantum dot; relaxation rate; rate detection; generalization of hermiticity; nonunitary dynamics; open quantum system; Coulomb charging energy; voltage switch; transient response; electronic nanosystem;

   Sammanfattning : The study of the dynamics of strongly confined, interacting open quantum systems has attracted great interest over the past years, due to potential applications in nanoelectronics, metrology as well as quantum information. Most recent experimental and theoretical research in this field has shifted attention towards electronic heat currents, recognizing their potential for practical purposes as well as for tests of fundamental theories, and also aiming to control the inevitable heat dissipation of any dynamically operated electronic device. LÄS MER

5. 4. 3-D rate dependent micromechanical model for polymer composites

   Författare :Vivekendra Singh; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; continuum damage; viscoelasticity; angle-ply laminates.; carbon epoxy composites; finite element; cohesive surface; viscoplasticity;

   Sammanfattning : Fibre reinforced polymeric composites are in high demand in automotive and aviation industries to improve fuel efficiency. However, the dynamic behaviour of composites is not very well understood. LÄS MER

7. 5. Direction-dependent processes - Theory and application

   Författare :Fredrik Rosenqvist; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; realisation; parameter estimation; direction-dependent dynamic processes; electronic noses; pulp and paper applications; piecewise-linear modelling;

   Sammanfattning : In this thesis, direction-dependent processes are described as processes whose responses differ in shape, strength and speed, depending on whether the input signal or output signal increases or decreases. The way in which these dynamics arise is discussed for three different applications; these applications are a thermomechanical pulp refiner, in which the motor load response to the hydraulic pressure is direction dependent, a paper machine, in which the calliper control in the calender section is direction dependent, and an electronic nose, in which the response to substrate concentration is direction dependent. LÄS MER