ABSTRACT
This chapter develops the basics of the theory of influence lines with reference to statically indeterminate or redundant elastic systems. The analytical method of construction of influence lines in statically indeterminate systems by the force method is to identify the dependence of primary unknowns versus the position of the unit load in the primary system and to represent the sought response through components due to redundant forces and the unit load acting separately. In the case of investigation of a required connection in a statically indeterminate system, there are no differences in the kinematic method of influence line construction. The main statement of the kinematic method of influence line construction is known as the Muller-Breslau principle. Graphic-analytical analysis by the force method can be fulfilled but only for very simple space systems.
