# HS-1506: Material Calibration with a Curve Difference Integral

In this tutorial, you will learn how to register a Compose, Python, or Templex function in HyperStudy.

The .py and .oml file contain a function that calculates the area between two curves.

The objective of this tutorial is to find the Radioss material parameter values so that the stress-strain curve of the tensile test simulation matches the tensile test experimental curve.

HS-1507: Material Calibration with Area Tool in Data Source provides an alternative method to set up this problem using the Area tool.

HS-4200: Material Calibration Using System Identification provides an alternative method to set up this problem using system identification.

- Create an input template from a Radioss file using the HyperStudy - Editor
- Register a Compose, Python, or Templex function
- Set up a study
- Run a system identification optimization study

## Model Definition

A quarter of a standard tensile test specimen is modeled using symmetry conditions. A traction is applied to a specimen via an imposed velocity at the left-end.

## Create Base Input Template

In this step, you can create the base input template in HyperStudy or use the base input template in the study Directory.

## Register Curve Difference Function

In this step you will register the curve difference function using Compose/OML, Python, or Templex.

The function curve_difference calculates the integral of the absolute value of the difference between two curves over the common domain of the supplied functions. This is a robust function that tends to zero only as the two functions become equal.

## Perform the Study Setup

## Perform Nominal Run

## Create and Evaluate Output Responses

In this step, you will use the curve_difference function to create and evaluate output responses.

In order to fit the RADIOSS stress-strain curve to the experimental data, you must compare the two curves.