Sökning: "fracture mechanics"

Visar resultat 31 - 35 av 250 avhandlingar innehållade orden fracture mechanics.

  1. 31. Microstructural aspects of the ductile-to-brittle transition in pressure vessel steels

    Författare :Torbjörn Narström; KTH; []
    Nyckelord :dectile-to-brittele transition; cleavage fracture; ductile fracture; fracture mechanics; constraint; initiation; pressure vessel steel; cleavage fracture stress;

    Sammanfattning : .... LÄS MER

  3. 32. Simulation of dynamic instabilities during high rate deformation of ductile bars and plates

    Författare :Kristina Nilsson; Mekanik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; numerical simulation; non-linear; wave propagation; multiple necking; necking; buckling; fracture; Mechanical engineering; Maskinteknik; finite elements; cohesive elements; dynamic; J2-flow theory; J2-deformation theory; viscoplastic; background inertia;

    Sammanfattning : In this thesis, some of the phenomena occurring in plates and cylindrical bars subjected to dynamic loading are investigated. Numerical simulations using a dynamic finite element code are performed for a number of different sized specimens with various initial surface imperfections. Typically imposed loading velocities are in the range 10m/s.. LÄS MER

  4. 33. On structural integrity with emphasis on rate effects of fracture toughness

    Författare :Mikael Lorentzon; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Sammanfattning : This thesis is concerned with structural integrity from a fracture mechanics point of view. The emphasis in this work is on rate effects of fracture toughness but all investigations deal with phenomena or problems within the frame work of non-linear fracture mechanics. LÄS MER

  5. 34. Microstructure based modelling of ductile fracture in quench-hardenable boron steel

    Författare :Rickard Östlund; Michael Worswick; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics; Centrumbildning - Centrum för högpresterande stål CHS ; Centre - Centre for High Performance Steel CHS ;

    Sammanfattning : Reduction of fuel consumption and emissions by vehicle weight minimization constitute a major driving force for the development of new materials and manufacturing processes in the automotive industry. Simultaneously formed and quenched boron steel components have higher strength to weight ratio than conventional mild steel components. LÄS MER

  7. 35. Modelling and characterisation of fracture properties of advanced high strength steels

    Författare :Rickard Östlund; Greger Bergman; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics; Centrumbildning - Centrum för högpresterande stål CHS ; Centre - Centre for High Performance Steel CHS ;

    Sammanfattning : Growing demands for passenger safety, vehicle performance and fueleconomy is a continuous driving force for the increase in use of advancedhigh strength steels (AHSS) in the automotive industry. Thesesteels area characterised by improved formability and crash worthinesscompared to conventional steel grades. LÄS MER