Integrated computational materials engineering (ICME) is an emerging discipline that can speed up product development by unifying material, design, fabrication, and computational power in a virtual environment. Develo...Integrated computational materials engineering (ICME) is an emerging discipline that can speed up product development by unifying material, design, fabrication, and computational power in a virtual environment. Developing and adapting ICME in industries is a grand challenge technically and culturally. To help develop a strategy for development of this new technology area, an ICME approach was proposed and implemented in optimizing thin welded structure design. The key component in this approach is a database which includes material properties, static strength, impact strength, and failure parameters for a weld. The heat source models, microstructure model, and thermo-mechanical model involved in ICME for welding simulation were discussed. The shell elements representing method for a fusion weld were introduced in details for a butt joint, lap joint, and a Tee joint. Using one or multiple solid elements representing a spot weld in a shell model was also discussed. Database building methods for resistance spot welding and fusion welding have been developed.展开更多
In 2004,Tong found bounds for the approximation quality of a regular continued fraction convergent to a rational number,expressed in bounds for both the previous and next approximation.The authors sharpen his results ...In 2004,Tong found bounds for the approximation quality of a regular continued fraction convergent to a rational number,expressed in bounds for both the previous and next approximation.The authors sharpen his results with a geometric method and give both sharp upper and lower bounds.The asymptotic frequencies that these bounds occur are also calculated.展开更多
文摘Integrated computational materials engineering (ICME) is an emerging discipline that can speed up product development by unifying material, design, fabrication, and computational power in a virtual environment. Developing and adapting ICME in industries is a grand challenge technically and culturally. To help develop a strategy for development of this new technology area, an ICME approach was proposed and implemented in optimizing thin welded structure design. The key component in this approach is a database which includes material properties, static strength, impact strength, and failure parameters for a weld. The heat source models, microstructure model, and thermo-mechanical model involved in ICME for welding simulation were discussed. The shell elements representing method for a fusion weld were introduced in details for a butt joint, lap joint, and a Tee joint. Using one or multiple solid elements representing a spot weld in a shell model was also discussed. Database building methods for resistance spot welding and fusion welding have been developed.
文摘In 2004,Tong found bounds for the approximation quality of a regular continued fraction convergent to a rational number,expressed in bounds for both the previous and next approximation.The authors sharpen his results with a geometric method and give both sharp upper and lower bounds.The asymptotic frequencies that these bounds occur are also calculated.
