Large inelastic deformation analysis of steel pressure vessels at high temperature

Dissertation

Research output: ThesisDissertationMonograph

Abstract

This publication describes the calculation methodology developed for a large inelastic deformation analysis of pressure vessels at high temperature. Continuum mechanical formulation related to a large deformation analysis is presented. Application of the constitutive equations is simplified when the evolution of stress and deformation state of an infinitesimal material element is considered in the directions of principal strains determined by the deformation during a finite time increment. A quantitative modelling of time dependent inelastic deformation is applied for reactor pressure vessel steels. Experimental data of uniaxial tensile, relaxation and creep tests performed at different laboratories for reactor pressure vessel steels are investigated and processed. An inelastic deformation rate model of strain hardening type is adopted. The model simulates well the axial tensile, relaxation and creep tests from room temperature to high temperature with only a few fitting parameters. The measurement data refined for the inelastic deformation rate model show useful information about inelastic deformation phenomena of reactor pressure vessel steels over a wide temperature range. The methodology and calculation process are validated by comparing the calculated results with measurements from experiments on small scale pressure vessels. A reasonably good agreement, when taking several uncertainties into account, is obtained between the measured and calculated results concerning deformation rate and failure location.
Original languageEnglish
QualificationDoctor Degree
Awarding Institution
  • Helsinki University of Technology
Place of PublicationEspoo
Publisher
Print ISBNs951-38-5856-1
Publication statusPublished - 2001
MoE publication typeG4 Doctoral dissertation (monograph)

Fingerprint

Steel structures
Temperature
Pressure vessels
Creep
Steel pressure vessels
Constitutive equations
Strain hardening
Experiments

Keywords

  • nuclear power plants
  • pressure vessels
  • steel constructions
  • inelastic material deformation
  • creep
  • high temperature
  • reactor accidents
  • analysis
  • finite element method
  • modelling

Cite this

@phdthesis{a04b1b7b82e74febbb76496043179312,
title = "Large inelastic deformation analysis of steel pressure vessels at high temperature: Dissertation",
abstract = "This publication describes the calculation methodology developed for a large inelastic deformation analysis of pressure vessels at high temperature. Continuum mechanical formulation related to a large deformation analysis is presented. Application of the constitutive equations is simplified when the evolution of stress and deformation state of an infinitesimal material element is considered in the directions of principal strains determined by the deformation during a finite time increment. A quantitative modelling of time dependent inelastic deformation is applied for reactor pressure vessel steels. Experimental data of uniaxial tensile, relaxation and creep tests performed at different laboratories for reactor pressure vessel steels are investigated and processed. An inelastic deformation rate model of strain hardening type is adopted. The model simulates well the axial tensile, relaxation and creep tests from room temperature to high temperature with only a few fitting parameters. The measurement data refined for the inelastic deformation rate model show useful information about inelastic deformation phenomena of reactor pressure vessel steels over a wide temperature range. The methodology and calculation process are validated by comparing the calculated results with measurements from experiments on small scale pressure vessels. A reasonably good agreement, when taking several uncertainties into account, is obtained between the measured and calculated results concerning deformation rate and failure location.",
keywords = "nuclear power plants, pressure vessels, steel constructions, inelastic material deformation, creep, high temperature, reactor accidents, analysis, finite element method, modelling",
author = "Kari Ikonen",
year = "2001",
language = "English",
isbn = "951-38-5856-1",
series = "VTT Publications",
publisher = "VTT Technical Research Centre of Finland",
number = "437",
address = "Finland",
school = "Helsinki University of Technology",

}

Large inelastic deformation analysis of steel pressure vessels at high temperature : Dissertation. / Ikonen, Kari.

Espoo : VTT Technical Research Centre of Finland, 2001. 151 p.

Research output: ThesisDissertationMonograph

TY - THES

T1 - Large inelastic deformation analysis of steel pressure vessels at high temperature

T2 - Dissertation

AU - Ikonen, Kari

PY - 2001

Y1 - 2001

N2 - This publication describes the calculation methodology developed for a large inelastic deformation analysis of pressure vessels at high temperature. Continuum mechanical formulation related to a large deformation analysis is presented. Application of the constitutive equations is simplified when the evolution of stress and deformation state of an infinitesimal material element is considered in the directions of principal strains determined by the deformation during a finite time increment. A quantitative modelling of time dependent inelastic deformation is applied for reactor pressure vessel steels. Experimental data of uniaxial tensile, relaxation and creep tests performed at different laboratories for reactor pressure vessel steels are investigated and processed. An inelastic deformation rate model of strain hardening type is adopted. The model simulates well the axial tensile, relaxation and creep tests from room temperature to high temperature with only a few fitting parameters. The measurement data refined for the inelastic deformation rate model show useful information about inelastic deformation phenomena of reactor pressure vessel steels over a wide temperature range. The methodology and calculation process are validated by comparing the calculated results with measurements from experiments on small scale pressure vessels. A reasonably good agreement, when taking several uncertainties into account, is obtained between the measured and calculated results concerning deformation rate and failure location.

AB - This publication describes the calculation methodology developed for a large inelastic deformation analysis of pressure vessels at high temperature. Continuum mechanical formulation related to a large deformation analysis is presented. Application of the constitutive equations is simplified when the evolution of stress and deformation state of an infinitesimal material element is considered in the directions of principal strains determined by the deformation during a finite time increment. A quantitative modelling of time dependent inelastic deformation is applied for reactor pressure vessel steels. Experimental data of uniaxial tensile, relaxation and creep tests performed at different laboratories for reactor pressure vessel steels are investigated and processed. An inelastic deformation rate model of strain hardening type is adopted. The model simulates well the axial tensile, relaxation and creep tests from room temperature to high temperature with only a few fitting parameters. The measurement data refined for the inelastic deformation rate model show useful information about inelastic deformation phenomena of reactor pressure vessel steels over a wide temperature range. The methodology and calculation process are validated by comparing the calculated results with measurements from experiments on small scale pressure vessels. A reasonably good agreement, when taking several uncertainties into account, is obtained between the measured and calculated results concerning deformation rate and failure location.

KW - nuclear power plants

KW - pressure vessels

KW - steel constructions

KW - inelastic material deformation

KW - creep

KW - high temperature

KW - reactor accidents

KW - analysis

KW - finite element method

KW - modelling

M3 - Dissertation

SN - 951-38-5856-1

T3 - VTT Publications

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -