3.1. Model Commands

These are the commands added to the interpreter to create the finite element model. A finite element model consists of Nodes, Elements, Constraints, and Loads. In OpenSees the Constraints are divided into two types: single-point constraints (SP_Constraints) for specifying the boundary condition for a specific degree-of-freedom at a node and multiple-point constraints (MP_Constraints) for specifying the relationship between the responses between the degrees-of-freedom at two separate nodes. The loads in OpenSees are assigned to LoadPatterns. Also associated with load patterns are TimeSeries objects ans sometime SP_Constraints when the user wants to specify time-varying SP_Constraints.


Fig. 3.1.1 OpenSees Model

In OpenSees there are commands to add each of these types of objects to a domain: