Introduction

The objective of this document is to present some of the different modelling tools available in OpenSees and to show the effects of variations on these tools on the numerical response of a simple structural system. These results can be used as a guide to the user in the selection of particular models to represent particular cases.

STUDY VARIABLES

The variables under consideration in this document are the following:


1. Concrete uniaxialMaterial Models:
	- Concrete01, Concrete02, Concrete03 (Concrete04 is evaluated only at the material level)
2. Steel uniaxialMaterial Models:
	- Steel01, Steel02, Steel03, ReinforcingSteel, Hysteretic
3. Force-Based element Models:
	- nonlinearBeamColumn and beamWithHinges
4. Plastic-Hinge Length for the beamWithHinges element.
	- variations on models for calculating Plastic-Hinge length
5. Geometric Transformation:
	- Linear Transformation and PDelta Transformation
6. Variation in Dead-Load Axial-Load Ratio
	- 5%, 10% & 20% for bridge column
	- 20%, 30% & 40% for building frame

MODELS

The following types of models were studied:

1. Material-Response Model -- The uniaxialMaterial models were subjected to a series of uniaxial tensile and compressive static loads of different patterns to evidentiate the different behavior of each material type.

2. Statically-Determinate SDOF Flexural Model -- BRIDGE COLUMN -- All of the variables described above were implemented into a numerical model of a cantilever column subjected to axial and lateral loads. The column was designed to be representative of a contemporary bridge column where the effects of shear and torsion can be neglected.

3. Statically-Indeterminate MDOF Flexural Frame -- BUILDING FRAME