Structural design is the methodical investigation of the stability,strength and rightly of structures, The basic objectives in structural analysis and design is to produce a structure capable of reslsting all applled loads without failure during its intended life-------Analyzes and Designs: The basic tasks of structural engineering relate numerical quantities of physical forces to physical configurations of force-resisting elements. Analysis is the process of determining forces in each element in a structure (such as a beam) when the configuration of elements is already defined. Design is the process of configuring elements to resist forces whose values are already known. Analysis and Design are complementary procedures in the overall process of designing new structures. After performing a preliminary design, the designer estimates the final configuration of elements of a structure, but only until an analysis is performed can the forces in those elements be known. After performing an analysis, the element forces are known, and the elements can be designed (their configuration can be chosen) more precisely. The process iterates between analysis and design until convergence is achieved.