Preparing the correct CSV structure is important for accurate fatigue calculations.
This guide explains the correct CSV format required for fatigue analysis and how
to prepare a file that can be processed by fatigue damage calculators.
1. What Is a CSV File?
CSV stands for Comma-Separated Values. It is a simple file format used to
store numerical data in rows and columns. CSV files are widely used in engineering
because they are easy to create, easy to process, and compatible with most analysis tools.
In fatigue analysis, CSV files are commonly used to store stress history data
recorded from sensors, experiments, or simulations.
2. Why Stress History Data Is Important
Fatigue damage occurs when a material experiences repeated stress cycles. To analyze
fatigue behavior, engineers must examine how stress varies during operation. This is
called a stress-time history or load history.
Fatigue analysis tools use this stress data to:
- Extract fatigue cycles using rainflow counting
- Determine stress ranges and amplitudes
- Calculate cumulative fatigue damage
- Estimate fatigue life using S–N curves
3. Correct CSV Format for Fatigue Analysis
The fatigue damage calculator requires a single-column CSV file containing
only stress values. Each row represents one stress measurement in the load sequence.
The file must contain numeric values only.
Example: Correct CSV Format
| Stress Value |
|---|
| 10 |
| 25 |
| -15 |
| 30 |
| -20 |
Each value represents a stress point in the loading history. The calculator processes
these values to extract fatigue cycles.
4. Important Formatting Rules
To ensure the CSV file works correctly, follow these formatting rules:
- Use only one column of numeric stress values
- Do not include headers such as “Stress” or “Time”
- Do not include units inside the cells
- Do not include text or symbols
- Each row should contain a single numeric value
Incorrect formatting may prevent the fatigue calculator from reading the data correctly.
5. Creating a CSV File Using Excel
You can easily create a CSV file using spreadsheet software such as Microsoft Excel.
- Enter stress values in a single column
- Do not add column titles
- Click File → Save As
- Select CSV (Comma delimited) format
- Save the file
The resulting CSV file can then be uploaded into fatigue analysis tools.
6. How the CSV Data Is Used in Fatigue Analysis
Once uploaded, the stress history data is processed using several fatigue analysis steps:
- Stress signal processing
- Rainflow cycle counting
- Stress range calculation
- Fatigue damage estimation using Miner’s Rule
These steps convert raw stress data into meaningful fatigue life predictions.
7. Using CSV Data in FatigueLab
You can upload stress history CSV files directly into the FatigueLab fatigue damage calculator
The calculator automatically performs rainflow counting, extracts stress cycles,
and calculates cumulative fatigue damage based on the provided data.
8. Summary
Preparing a correctly formatted CSV file is essential for reliable fatigue analysis.
By using a single column of stress values without headers or text, engineers can ensure
that fatigue analysis tools correctly process the data and produce accurate fatigue
damage calculations.