From a point of view to utilize fracture mechanics of concrete for the solution of engineering problems, prob- lems in crack modeling, computational algorithm, and damping implementation are discussed in conjunction with safety assessment of concrete dam against large earthquake.…
From a point of view to utilize fracture mechanics of concrete for the solution of engineering problems, prob- lems in crack modeling, computational algorithm, and damping implementation are discussed in conjunction with safety assessment of concrete dam against large earthquake. It is shown that the formulation for the crack- embedded element has an analogy with that of computational plasticity. This analogy enables us to utilize the return-mapping algorithm well established in computational plasticity for the dynamic analysis of crack growth in concrete. The ways of implementing damping to avoid diffused cracking are presented and simple exam- ples of numerical analysis are shown to demonstrate the effect of damping and the performance of .appropriate damping implementation for cracked elements. INTRODUCTION concept that no crack is allowed under earthquake ex- A long time has passed since fracture mechanics is ap- citation. However, it is possible that cracks are formed plied to concrete and concrete structures and a great and propagated up to a certain point in the dam body number of studies on modeling and numerical meth- during earthquake. The role of computational fracture ods for crack growth in concrete have been carried mechanics of concrete is to predict the dynamic crack out. It is at a stage to utilize the accumulated knowl- growth in concrete dam under large earthquake exci- edge to solve real engineering problems. In this pa- tation.