Sökning: "stiffness measurement"

Visar resultat 11 - 15 av 89 avhandlingar innehållade orden stiffness measurement.

  1. 11. Local variation in bending stiffness in structural timber of Norway spruce : for the purpose of strength grading

    Författare :Min Hu; Marie Johansson; Linnéuniversitetet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; digital image correlation; fibre angle; high resolution; laser scanning; local stiffness; MOE profile; mode shape curvature; strain field; strength grading; structural timber; tracheid effect; Digital image correlation; fibervinkel; laserskanning; lokal styvhet; MOE-profil; töjningsfält; hållfasthetssortering; konstruktionsvirke; trakeideffekt; Forestry and Wood Technology; Skog och träteknik;

    Sammanfattning : Most strength grading machines on the European market use an averagemodulus of elasticity (MOE), estimated on a relatively large distance along awood member, as the indicating property (IP) to bending strength. Theaccuracy of such grading machines in terms of coefficient of determination israther low at R2 ≈ 0.5. LÄS MER

  2. 12. Assessment of existing concrete bridges : bending stiffness as a performance indicator

    Författare :Markus Bergström; Paulo J. de S. Cruz; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Structural Engineering; Konstruktionsteknik;

    Sammanfattning : Optimizing the use of existing civil reinforced concrete (RC) structures could be interpreted in such a way as to say that the capacity should be used and taken care of in an effective manner, both from a technical and economical point of view, keeping the safety in mind. Achieving this requires thorough understanding of the structure and also of the tools used for assessing current and future capacity and needs. LÄS MER

  3. 13. Three-Dimensional Load-Deformation Relationships of Arbitrarily Loaded Coiled Springs

    Författare :Lars Lindkvist; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; extended stiffness model; helical spring; non-linear deformation; stiffness matrix; coiled spring; arbitrary load; large deformation; three-dimensional;

    Sammanfattning : This paper reports the development of a computer based tool that can be used to predict the three-dimensional load-deformation relationships of arbitrarily loaded coiled springs. The non-linear deformation of the spring is calculated by dividing the spring into small elements for which the load-deformation relationships can be considered to be linear. LÄS MER

  4. 14. Mechanics of Cross-Laminated Timber

    Författare :Dietrich Buck; Olle Hagman; Dick Sandberg; Mats Ekevad; Mikael Sjödahl; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CLT assembly; CLT manufacture; Crosslam; DIC analysis; Digital speckle photography; Full-field mechanics; Laminated wood product; Mass timber engineering; Non-contact measurement; Non-destructive; Optical measurement; Panel configuration; Strain localization; X-lam; Alternativ byggmetod; Bildkorrelation; Hållbart byggande; KL- trä; Korslimmat trä; Skjuvtöjning; Massivträ; Träkonstruktion; Träteknik; Wood Science and Engineering;

    Sammanfattning : Increasing awareness of sustainable building materials has led to interest in enhancing the structural performance of engineered wood products. Wood is a sustainable, renewable material, and the increasing use of wood in construction contributes to its sustainability. LÄS MER

  5. 15. Very preterm birth and fetal growth restriction in adolescence - Cardiovascular and renal aspects

    Författare :Jonas Liefke; Lund Klinisk fysiologi; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Preterm and low birth weight; Fetal growth restriction; Magnetic resonance imaging MRI ; Cardiac function; Preterm birth; Adolescence; Kidney function; Kidney anatomy histology; Cardiovascular biomarkers; Arterial stiffness; Ambulatory blood pressure measurement; Biochemical makers;

    Sammanfattning : This thesis applied magnetic resonance imaging (MRI) to investigate to what extent very preterm birth due to early onset fetal growth restriction (FGR) impacts the cardiovascular system and kidneys in adolescence. The thesis further investigated whether FGR exacerbates the organ-specific effects of very preterm birth. LÄS MER