Sökning: "Split Hopkinson pressure bar"

Visar resultat 1 - 5 av 14 avhandlingar innehållade orden Split Hopkinson pressure bar.

1. 1. A Method for Dispersive Split Hopkinson Pressure Bar Analysis Applied to High Strain Rate Testing of Spruce Wood

   Författare :Svante Widehammar; Karl-Gustav Sundin; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; split Hopkinson; wave propagation; dispersion; Hamilton s principle; strain rate; calibration; spruce; wood; Materialvetenskap; Materials science; Teknisk materialvetenskap; teknisk fysik med inriktning mot hållfasthetslära; Technical Physics;

   Sammanfattning : En metod för dispersiv analys av försök med delad hopkinsonstång tillämpad på provning av granved vid hög töjningshastighetSyftet var att etablera en metod för att studera sambandet mellan spänning och töjning för granved vid hög töjningshastighet. Detta åstadkoms genom att anpassa och något vidareutveckla tekniken med delad hopkinsonstång ("Split Hopkinson Pressure Bar", SHPB). LÄS MER

3. 2. Influence of transient loading on lubricant density and frictional properties

   Författare :Bert-Olof Åhrström; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements;

   Sammanfattning : This licentiate thesis deals with the influence of transient loading, at high pressures, on the pressure-dilatation relation and frictional properties of lubricants. A Split-Hopkinson pressure bar and a Ball and Bar apparatus have been used for the experiments. LÄS MER

4. 3. High strain-rate experiments using high-speed photography

   Författare :Jörgen Kajberg; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

   Sammanfattning : In many technical processes, material is deformed under conditions that contain high strain rates. Examples of such processes are collisions, impact, penetration, metal forming and crack propagation. Constitutive models including viscoplasticity have been proposed for these kinds of situations. LÄS MER

5. 4. Methods for mechanical testing based on analysis of elastic waves in rods

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

   Sammanfattning : This thesis summarizes six papers on development and applications of a method to evaluate the normal force and particle velocity at any cross-section of a nonuniform rod from measurements of strain at two different cross-sections. In Paper A the method is developed. It is an extension of that developed by Lundberg and Henchoz for uniform rods. LÄS MER

7. 5. Identification of Viscoelastic Materials by Use of Wave Propagation Methods

   Författare :Saed Mousavi; Bengt Lundberg; Urmas Valdek; Janne Färm; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; Identification; Viscoelastic; Complex modulus; Complex Poisson s ratio; wave; Impact; Teknisk fysik; Engineering physics; Teknisk fysik;

   Sammanfattning : Complex moduli and Poisson’s ratio have been estimated using extensional and torsional wave experiments. The data were used for assessment of linearity and isotropy of two polymers, polymethyl methacrylate (PMMA) and polypropylene (PP). The responses of both materials were found to be close to linear and isotropic. LÄS MER