Optimization of process parameters to maximize ultimate tensile strength of friction stir welded dissimilar aluminum alloys using response surface methodology

Aluminium alloys generally present low weldability by traditional fusion welding process. Development of the friction stir welding （FSW） has provided an alternative improved way of producing aluminium joints in a faster and reliable manner. The quality of a weld joint is stalwartly influenced by process parameter used during welding. An approach to develop a mathematical model was studied for predicting and optimizing the process parameters of dissimilar aluminum alloy （AA6351 T6-AA5083 Hlll）joints by incorporating the FSW process parameters such as tool pin profile, tool rotational speed welding speed and axial force. The effects of the FSW process parameters on the ultimate tensile strength （UTS） of friction welded dissimilar joints were discussed. Optimization was carried out to maximize the UTS using response surface methodology （RSM） and the identified optimum FSW welding parameters were reported.

通用强度折减点安全系数的定义及在边坡稳定分析中的应用

针对传统强度折减点安全系数取值的局限性以及对多参数准则无法普遍适用的缺陷,引入应力点极半径以及临界极半径的概念,给出了通用强度折减点安全系数的定义及其计算方法。以某堤防工程为例,计算传统的刚体极限平衡法和有限元弹塑性极限分析法下的土坡整体安全系数进行比较,考察该方法在土坡稳定分析中的适用性。