engleski

Volumetric Constraint in Microplane Model for Concrete

Arc-length method is a well-known tool for post-peak analysis of structures with a lot of implementation examples available in literature. However, most of the examples deal with either geometric or hardening-material nonlinearities. Authors have tried to implement the method in microplane model (for concrete) which is a softening material model. Originally microplane model is based on initial stiffness procedure and displacement control to perform post-peak analysis. Introduction of the usual arc-length procedure has resulted in serious instabilities in the post-peak regime. In order to stabilize the procedure a variable had to be chosen to serve as a guidance variable in determination of arc-length parameters. This has significantly improved the performance of computer code and allowed some simplifications, too. Consistent linearization of constraint equation further stabilized the procedure. Some numerical examples illustrate the behavior of the model.

microplane model; volumetric control; arc-length method

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