Distinct Element Modelling of Unreinforced Masonry Wall Under Seismic Loads with and without Cable Retrofitting

To retrofit and strengthen existing unreinforced masonry (URM) structures to resist the potential earthquake damages has become an important issue in Australia. In order to secure the performance of URM under seismic loading in the future, a research project was carried out aimed at developing a simple and high strength seismic retrofitting technique for masonry structures. A series of experimental testing on URM walls retrofitted with an innovative technique by cable system have been conducted. The results indicated that both the strength and ductility of the tested speci-mens were significantly enhanced with the technique. An analytical model which is based on Dis-tinct Element Method (DEM) has also been developed to simulate the behaviour of URM walls be-fore and after retrofitting. The model is then further developed by applying a seismic wave to the wall to simulate the wall behavior under earthquake loads before and after retrofitting.

环氧树脂模填加剂模压处理后对MOS场效应晶体管引线键合可靠性的影响(英文)

氧化硅填充环氧树脂在作为芯片封装的密封中对微电子器件的可靠性与功能起着一种主要影响。在帮助了解铝引线键合内部类似功率MOS场效应晶体管的一种含铅电子组件的可靠性,在热力学机械特性试验结果表明由于栅离层的焊线接近引线框架,在键合后从-40℃到125℃的功率热循环下,导致了键合样品的一种电气开路。采用有限元模型模拟了这种封装应力,根据经验检验结果本模拟预示那些在引线键合支撑的焊跟处具有较高的平面剪切力。由数字模拟和试验数据获得的结果可作为选定适当模塑添加剂的一种指导路线。