Indeterminate structures are encountered often in civil engineering problems, and a number of methods can be used to analyze them. Before computers became prevalent in engineering practice, the moment distribution method was perhaps the most popular technique for analyzing indeterminate beams and frames. At the present time, however, some academic curricula do not adequately cover moment distribution, and focus instead on the more modern flexibility (force) and stiffness (displacement) methods. This review deals with all three methods for the analysis of indeterminate structures; the reader may use whichever method is most appealing. For particular examples, however, one method may have an advantage over another, and this is pointed out. For indeterminate trusses, the flexibility method is the most suitable one for hand-calculations.
Deformations and forces in indeterminate structures can be caused by loads, thermal effects, support movements and/or prestrain effects (i.e., the stretching or bending of a member to make it fit). Since prestrain effects are not commonly encountered in practice, only loads, thermal effects and support movements are considered in this review.
When using the flexibility method of analysis, it is necessary to compute deflections of determinate structures. A number of methods such as the unit load method, moment-area method, conjugate beam method, etc., are available to compute deflections. Only the unit load method is used in this review since it is the most versatile and can be used for beams, frames and trusses.