Regression Adaption

tbd

This MATLAB script, designed for mechanical test data analysis, provides a comprehensive set of methods for importing, processing, and analyzing data from mechanical tests such as tensile tests, compression tests, or any other type of materials testing. The script allows users to perform various tasks, including data import, smoothing, peak detection, plateau identification, regression analysis for stiffness calculation, and reference value determination.

Key Features:

1. Data Import:

• The part includes a method to import data from ".tra" files generated by testXpert (Zwick).

2. Preconditioning Removal:

• Users can remove preconditioning data from the imported dataset to focus exclusively on the failure testing data. The method identifies the transition point from preconditioning to failure testing.

3. Data Smoothing:

• Smoothing methods like moving average and lowess can be applied to the failure testing data. Users can adjust the smoothing parameters to obtain a clearer representation of the force-displacement curve.

4. Peak Detection:

• The script can automatically identify local maxima (peaks) in the smoothed data. Users can customize peak detection parameters, such as minimum peak distance, prominence, and height.

5. Plateau Identification:

• Plateaus in the data, often associated with specific material behaviors, can be detected using the derivative of the force-displacement curve. The method identifies regions where the derivative is close to zero.

6. Stiffness Calculation -> REGRESSION ADAPTION:

• Stiffness, a critical material property, can be calculated using linear regression. The class allows users to specify the range for regression analysis, providing flexibility in focusing on specific regions of interest.

7. Reference Value Calculation:

• A reference value for stiffness can be determined based on user-defined criteria. This includes specifying a reference force value and a reference displacement step. The method also identifies reference points on the force-displacement curve.

8. Data Visualization:

• It provides an example of how to display plots for one of the test data sets.

Use Cases:

• Material scientists and engineers conducting mechanical tests on various materials can use this script to streamline their data analysis process.
• Researchers can efficiently process and extract critical material properties, such as stiffness, from test data.
• The class facilitates the identification of important features in mechanical test data, such as peaks and plateaus, which are often associated with material failure modes.

Benefits:

• Provides a structured and organized approach to mechanical test data analysis.
• Offers flexibility through customizable parameters for various analysis tasks.
• Enables efficient and accurate determination of material properties.

Compatibility:

The class is compatible with MATLAB and can be easily integrated into existing workflows for materials testing and characterization.

Disclaimer:

This MATLAB class is provided on the MATLAB File Exchange for educational and research purposes. Users should ensure that the class meets their specific analysis requirements and may need to adapt it accordingly. The code is provided "as-is," and the author assumes no responsibility for its use or any consequences thereof.

MATLAB Version Compatibility:

MATLAB 2020b

Keywords:

mechanical testing, data analysis, material properties

References:

Micheler, C., Lang, J., Bäumlisberger, A., Wachtel, N., Wilhelm, N., Schaack, V., Eisenhart-Rothe, R. and Burgkart, R. (2023) Biomechanical Test Setup for the Investigation of Forehead Suture Techniques. Current Directions in Biomedical Engineering, Vol. 9 (Issue 1), pp. 532-535. https://doi.org/10.1515/cdbme-2023-1133