Search for dissertations about: "Thermal cracking risk"

Showing result 1 - 5 of 18 swedish dissertations containing the words Thermal cracking risk.

  1. 1. Thermal Crack Risk Estimation and Material Properties of Young Concrete

    Author : Anders Hösthagen; Jan-Erik Jonasson; Mårten Larson; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Thermal cracking risk; young concrete; Equivalent Restraint Method; strength development; heat of hydration; creep; shrinkage; thermal dilation; modeling; field observations; Structural Engineering; Konstruktionsteknik;

    Abstract : This thesis presents how to establish a theoretical model to predict risk of thermal cracking in young concrete when cast on ground or an arbitrary construction. The crack risk in young concrete is determined in two steps: 1) calculation of temperature distribution within newly cast concrete and adjacent structure; 2) calculation of stresses caused by thermal and moisture (due to self-desiccation, if drying shrinkage not included) changes in the analyzed structure. READ MORE

  2. 2. Thermal cracking of young concrete : partial coefficients, restraint effects and influence of casting joints

    Author : Martin Nilsson; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Structural Engineering; Konstruktionsteknik;

    Abstract : Cracks can occur due to temperature induced movements during the hardening phase of concrete. Thermal cracks are not decisive for the load-bearing capacity but cause costs for repair and may reduce the life of the structure. The risk of cracking can be judged through safety values, (partial coefficients) given in building codes. READ MORE

  3. 3. Weld Cracking of Precipitation Hardening Ni-based Superalloys - Investigation of repair welding characteristics and susceptibility towards strain age cracking

    Author : Fabian Hanning; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gleeble; Haynes 282; Waspaloy; welding; ATI 718Plus®; weldability; post-weld heat treatment; weld cracking; strain age cracking; hot cracking; Nickel-based superalloys;

    Abstract : High temperature resistance and strength requirements make nickel-based superalloys the material of choice for the hot section of aero engines. Fabrication in terms of combining wrought and cast parts in the manufacturing of hot structural components enables component optimisation via the use of wrought high-strength parts, where geometrical constraints allow, and cast parts to produce complex geometries. READ MORE

  4. 4. Cracking in concrete : crack prevention with air-cooling and crack distribution with steel fibre reinforcement

    Author : Patrik Groth; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Structural Engineering; Konstruktionsteknik;

    Abstract : This Licentiate Thesis consists of four parts. The first two parts, paper A and B, deal with air-cooling by means of embedded pipes in order to reduce thermal cracking in concrete structures. These two papers are submitted for publication to RILEM Journal; ‘Materials and Structures'. READ MORE

  5. 5. Thermal impact on rolling contact fatigue of railway wheels

    Author : Sara Caprioli; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Railway wheels; Thermomechanical finite element analysis; Frictional rolling contact; Thermal fracture; Tread braking; Rolling contact fatigue;

    Abstract : Rolling contact fatigue (RCF) is a very common and costly damage mechanism for rails and wheels. This thesis investigates the influence of combined thermal and mechanical loading on RCF of railway wheels on the basis of numerical predictions. READ MORE