Implementation of new element and material for OpenSees in .NET environment (C# and MATLAB)
Implementation of new element and material for OpenSees in .NET environment (C# and MATLAB)close

This example shows how to implement a new element and material in .NET environment for OpenSees via delegates. also, MATLAB and C# code of 2D Truss element provided for static and dynamic analysis

Three-Dimensional rigid Frame subjected to bi-directional earthquake ground motion
Three-Dimensional rigid Frame subjected to bi-directional earthquake ground motionclose

The model consists of three stories and one bay in each direction. Rigid diaphragm multi-point constraints are used to enforce the rigid in-plane stiffness assumption for the floors. Gravity loads are applied to the structure and the 1978 Tabas acceleration records are the uniform earthquake excitations.

Weight Optimization of 10-bar truss structure with MATLAB
Weight Optimization of 10-bar truss structure with MATLABclose

For loading OpenSees.NET in MATLAB, we use addAssembely command. When .NET assembly successfully loaded in MATLAB, we can create the model. theDomain is the container of all components of the structure. NodeWrapper, TrussWrapper, ElasticMaterialWrapper and SP_ConstaintWrapper commands generate an instance of Node, Truss, ElasticMaterial and SP_Constaint OpenSees objects respectively

A large deformation cantilever beam subjected to end bending moment
A large deformation cantilever beam subjected to end bending momentclose

Nonlinear geometric analysis of A cantilever beam subjected to end bending moment

Nonlinear Cantilever Column: Inelastic Uniaxial Materials in Fiber Section
Nonlinear Cantilever Column: Inelastic Uniaxial Materials in Fiber Sectionclose

In this example, the Uniaxial Section of Example 2b is replaced by a fiber section. Inelastic uniaxial materials are introduced in this example, which are assigned to each fiber, or patch of fibers, in the section.

Nonlinear Cantilever Column: Uniaxial Inelastic Section
Nonlinear Cantilever Column: Uniaxial Inelastic Sectionclose

The nonlinear beam-column element that replaces the elastic element of Example 2a requires the definition of the element cross section, or its behavior. In this example, the Uniaxial Section used to define the nonlinear moment-curvature behavior of the element section is "aggregated" to an elastic response for the axial behavior to define the required characteristics of the column element in the 2D model. In a 3D model, torsional behavior would also have to be aggregated to this section.

A simple model of an elastic cantilever column
A simple model of an elastic cantilever columnclose

Example 1-a & 1-b is a simple model of an elastic cantilever column. The objective of this example is to give an overview of input format.