This paper presents comparison of numerical models used in an analysis of a road bridge deck. The models were adapted for computing the live load distribution coefficients in composite concrete bridge deck. The load d...This paper presents comparison of numerical models used in an analysis of a road bridge deck. The models were adapted for computing the live load distribution coefficients in composite concrete bridge deck. The load distribution method was chosen for assessment of the usability of different numerical model in slab bridge deck analysis. The goal of the study is to determine a simplest but still accurate numerical model to estimate live load effects on composite slab bridge. In the analysis, the well-established grillage approach was adapted for representation of the bridge deck as a basic model as well as more sophisticated three-dimensional models which was supposed to better represent the real behavior of the deck under concentrated wheel loads. The bridge deck was effectively modeled using beam and shell elements. The grillage method compares well with the finite-element method. This finding is allowed to establish simplification in numerical modeling of slab bridge decks for live load effect computations.展开更多
Heat transfer of an SI engine's piston is calculated by employing three different methods based on resistor-capacitor model with the help of MATLAB code, and then the piston is thermo-mechanically analyzed using c...Heat transfer of an SI engine's piston is calculated by employing three different methods based on resistor-capacitor model with the help of MATLAB code, and then the piston is thermo-mechanically analyzed using commercial ANSYS code. The results of three methods are compared to study their effects on the piston thermal behavior. It is shown that resistor-capacitor model with less number of equations and consequently less solution time, is an appropriate method for solving problems of engine piston heat transfer. In the second part, the thermal stresses due to non-uniform temperature distribution, and mechanical stresses due to mechanical loads are calculated. Finally, the temperature distributions as a thermal load along with mechanical loads are applied to the piston to determine the total stress distribution and critical fracture zones. It is found that the amount of thermal stresses is considerable.展开更多
文摘This paper presents comparison of numerical models used in an analysis of a road bridge deck. The models were adapted for computing the live load distribution coefficients in composite concrete bridge deck. The load distribution method was chosen for assessment of the usability of different numerical model in slab bridge deck analysis. The goal of the study is to determine a simplest but still accurate numerical model to estimate live load effects on composite slab bridge. In the analysis, the well-established grillage approach was adapted for representation of the bridge deck as a basic model as well as more sophisticated three-dimensional models which was supposed to better represent the real behavior of the deck under concentrated wheel loads. The bridge deck was effectively modeled using beam and shell elements. The grillage method compares well with the finite-element method. This finding is allowed to establish simplification in numerical modeling of slab bridge decks for live load effect computations.
文摘Heat transfer of an SI engine's piston is calculated by employing three different methods based on resistor-capacitor model with the help of MATLAB code, and then the piston is thermo-mechanically analyzed using commercial ANSYS code. The results of three methods are compared to study their effects on the piston thermal behavior. It is shown that resistor-capacitor model with less number of equations and consequently less solution time, is an appropriate method for solving problems of engine piston heat transfer. In the second part, the thermal stresses due to non-uniform temperature distribution, and mechanical stresses due to mechanical loads are calculated. Finally, the temperature distributions as a thermal load along with mechanical loads are applied to the piston to determine the total stress distribution and critical fracture zones. It is found that the amount of thermal stresses is considerable.
