Showing papers by "Nenad Bićanić published in 2004"

Gradient enhanced thermo‐mechanical damage model for concrete at high temperatures including transient thermal creep

Abstract: A thermo-mechanical model for concrete under transient high temperatures is presented. Particular emphasis is placed on the transient thermal creep model, which can be seen as an extension of Thelandersson's formulation, and the gradient-enhanced damage model that has been extended here to include temperature dependency. Degradation of the material stiffness due to exposure to elevated temperatures is included via a simple thermal damage model. The model's performance is illustrated on several benchmark problems under both transient and steady state heating conditions.

Improved phenomenological modelling ofrntransient thermal strains for concreternat high temperatures

Abstract: Several extensions to the Thelandersson phenomenological model for concrete under transientrnhigh temperatures are explored. These include novel expressions for the temperature degradation of thernelastic modulus and the temperature dependency of the coefficient of the free thermal strain. Furthermore,rna coefficient of thermo mechanical strain is proposed as a bi-linear function of temperature. Goodrnqualitative agreement with various test results taken from the literature is demonstrated. Further extensionsrninclude the effects of plastic straining and temperature dependent Poisson? ratio. The models performancernis illustrated on several simple benchmark problems under uniaxial and biaxial stress states.