10:00 AM - 11:00 AM
Yabiao (Albert) Sun, University of Toronto, Canada
Materials Science and Technology Division Seminar
High Temperature Materials Laboratory (Building 4515), Room 265
Email: Edgar Lara-CurzioPhone:
Dr. Sun will briefly present his research on the following topics, which has been published in recent years at international conferences and in journals. 1) The Simulations of CANDU® Fuel Bundle under Static Mechanical Loads and Refueling Loads Using LS-DYNA Finite Element Models LS-DYNA is used for the analysis of CANDU®fuel assemblies subjected to static mechanical loads and refueling hydraulic loads from coolant flow. When modeling these conditions, the FE models consider the non-linear mechanisms for the following phenomena: including mechanicaldriving forces (such as gravity, hydraulic drag and friction force), contact constraints on assemblies at side-stops, inter cladding element contacts through the mating spacers, fuel cladding to pressure tube contact at bearing pads, endplate to endplate contacts in fuel assembly string, and relative assembly misalignment in fuel string. 2) Stress Analysis of Assembly Weld For ACR-1000 Fuel The operating conditions of the ACR-1000 reactor differ from existing CANDU® reactor experiences such that there is expected to be a decrease in the ductility of the assembly welds in comparison to existing CANDU® designs. Key differences in operating conditions are the higher burnup and the higher coolant temperature of ACR-1000 fuel. This sub-topic presents the results of an assessment of the strength of the assembly weld of the ACR-1000 fuel assemblies. 3) An Analytical Approach and Numerical Simulation to Predict Refueling Impact Force of CANDU® Fuel Predictions using a closed-form model and simulations using detailed LS-DYNA finite element model for the impact force and the resulting stress in fuel assemblies were presented together with experimental measurements. 4) Simulation and Experimental Study on Nano-reinforced Composites Interfaces This study evaluates the influence of nanofillers on the reinforcement of an adhesively bonded layer under mode-I fracture toughness using multiscale modeling. In this approach, coarse-grain molecular dynamics are coupled with continuum mechanics. The molecular dynamics domain and the finite element domain are overlapped in a handshaking subdomain. The implementation of coarse-grain molecular dynamics radically reduces the size of the problem. An explicit algorithm coupling the two methodologies was developed and used to determine the energy release rates of cracks in adhesively bonded composite joints with varying amounts of nano-reinforcement in the adhesive layer. Both the quality of the prediction of the multiscale model and the influence of the nanofillers are evaluated and discussed.