Use of Reinforcement in a Nonlinear, Incremental Structural Analysis.

Abstract : This report discusses the modeling of reinforcement in a finite element method known as nonlinear, incremental structural analysis (NISA). Several simple problems are used to show how reinforcement may be included in a finite element analysis. The problems include an axially loaded beam, a simply supported beam in bending, and a fully supported slab. Closed form solutions for each of the problems are demonstrated. After the theory for each of the simple problems has been presented, example problems are provided to show how the equations are used. The hand calculations are compared to results obtained from finite element analyses. Agreement between hand calculations and numerical results proved to be very good. The report concludes with an example of a NISA performed on a full-scale massive concrete structure. It is concluded that reinforcement is valuable to include in a model if cracking may be expected, but it does not provide significant benefits unless cracking actually occurs. (MM)