Sökning: "stiffness modulus"

Visar resultat 21 - 25 av 127 avhandlingar innehållade orden stiffness modulus.

1. 21. Dynamic properties of two pedestrian timber bridges : Experimental and numerical analysis at several stages of construction

   Författare :Jens Bergenudd; Jean-Marc Battini; Roberto Crocetti; Patricia Hamm; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic analysis; Modal analysis; Pedestrian bridge; Timber; Railings; Asphalt; Slip modulus; Finite element modelling; Dynamisk analys; Modal analys; Gång- och cykelbro; Trä; Räcken; Asfalt; Förskjutningsmodul; Finita element modellering.; Bro- och stålbyggnad; Structural Engineering and Bridges;

   Sammanfattning : Pedestrian bridges can beneficially be made from timber in order for our society to reach a sustainable future. This positive development is partly made possible due to advances in engineered wood products (e.g. glued laminated timber) and the possibilities for pre-fabrication of structural parts. LÄS MER

3. 22. Mechanical Analysis of Melamine-Formaldehyde Composites

   Författare :Per-Ola Hagstrand; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; melamine-formaldehyde; damage; composites; alumina trihydrate; stiffness modelling; cyclic loading; rheokinetics; flax fibres; in-situ SEM;

   Sammanfattning : Planar random fibre composite materials based on melamine-formaldehyde (MF), one of the hardest and stiffest isotropic polymers that is known, have been developed recently on an industrial scale. In this thesis the mechanical behaviour of these materials is systematically investigated for the first time. LÄS MER

4. 23. Sample preparation effect on measured rheological properties of bitumen using Dynamic Shear Rheometer

   Författare :Maya Sheidaei; Trafik och väg; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Bitumen rheology; dynamic shear rheometer; complex modulus;

   Sammanfattning : Through improved bitumen characterization, which will increase the road'sdurability, stability, and performance, pavement engineering can apply thesustainability notion that should be followed in all disciplines nowadays. The newtechniques distinguish between the rheological properties of bituminous binders as a function of loading time and temperature to depict real-world behavior rather than only considering empirical properties. LÄS MER

5. 24. Molecular Interactions in Thin Films of Biopolymers, Colloids and Synthetic Polyelectrolytes

   Författare :Johansson Erik; Lars Wågberg; Andreas Fery; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polyelectrolyte multilayers; Layer-by-Layer assembly; Adhesion; Adsorption; Young s modulus; Mechanical buckling; AFM; JKR; SPAR; QCM-D; SIEBIMM; PAH; PAA; Starch; NFC; Nanocellulose;

   Sammanfattning : The development of the layer-by-layer (LbL) technique has turned out to be an efficient way to physically modify the surface properties of different materials, for example to improve the adhesive interactions between fibers in paper. The main objective of the work described in this thesis was to obtain fundamental data concerning the adhesive properties of wood biopolymers and LbL films, including the mechanical properties of the thin films, in order to shed light on the molecular mechanisms responsible for the adhesion between these materials. LÄS MER

7. 25. Characterising the Deformation Behaviour of Unbound Granular Materials in Pavement Structures

   Författare :Mohammad Shafiqur Rahman; Sigurdur Erlingsson; Charles Schwartz; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; unbound granular materials; resilient modulus; permanent deformation; moisture; model; multistage; repeated-load triaxial test; Transportvetenskap; Transport Science; Civil and Architectural Engineering; Byggvetenskap;

   Sammanfattning : Unbound granular materials (UGMs) used in the base and sub-base layers of flexible pavements play a significant role in the overall performance of the structure. Proper understanding and characterization of the deformation behaviour of UGMs in pavement structures are, therefore, vital for the design and maintenance of flexible pavements. LÄS MER