The quality of surface mount technology (SMT) product solder joint was key factor for SMT products. In this paper, for chip components, a fuzzy fault diagnosis principle of SMT products was analyzed. And the total framework of fault diagnosis system was built based on solder joint shape theory. Geometrical shape parameters which reflected chip components solder joint quality were analyzed and d...

Strength reduction in structures like an aircraft could be resulted as cyclic loads over a period of time and is an important factor for structural life prediction. Service loads are emphasized at the regions of stress concentration, mostly at the connection of components. The initial flaw prompting the service life was expected by using the Equivalent Initial Flaw Size (EIFS) which has been re...

Ultra low cycle fatigue (ULCF) is a phenomenon that can be summarily defined as the deterioration of material properties under high amplitude cyclic loading, under which failure is reached typically within ten to twenty cycles. This phenomenon is observed in extreme loading scenarios such as earthquakes or exceptional winds where large cyclic strains are expected. Particularly sensitive are str...

A method for optimally synthesizing multicomponent structural assemblies of an aluminum space frame (ASF) vehicle body is presented, which simultaneously considers structural stiffness, manufacturing and assembly costs and dimensional integrity under a unified framework based on joint libraries. The optimization problem is posed as a simultaneous determination of the location and feasible types...

the structural slenderness ration (height/ with) is one of the title that can be discussed in quake design of building. but unfortunately, in  iranian code isn’t mention this mater.in this article, bending and bracying structures system are chosen with slenderness ratio 2 upto 6. (11, 17, 23, 29, 35 stage).all of structure are analysed and designed in linear method, then analysed in unlinear me...