Use this dialog to import Stress-Strain (Tension) data for thermoplastic materials. This is used for the structural analysis of the finished part.
To access this dialog, right-click
in the Study Tasks pane, then select
Details or
Edit from the drop-down menu.
The Ramberg-Osgood equation predicts the material behaviour in the non-linear regions of the stress-strain curve. Data from the
Stress-Strain (Tension) table is used to calculate the coefficients used in the
Ramberg-Osgood equation. Each unique set of temperature, relative humidity and strain rate will generate a line in this table provided there is enough data available. The following is required:
- Minimum of fifteen data points for a given angle
- Results are available for at least two angles. Currently only 0º, 45°, and 90° are supported.
- These results must be for the tensile properties of the material.
Note: The Ramberg-Osgood equation in no way alters the
Moldflow analysis. It is used to provide additional material information when exporting results for structural analysis.
Dialog Elements
| Dialog element | Explanation |
|---|---|
| Stress-Strain (Tension) | Each line of the table represents a set of assigned values for Stress, Strain, Angle of testing relative to the flow direction, Temperature, Relative Humidity, and Strain rate for the material in tension. If the dialog was opened using the Edit option, values can be entered manually into the table. |
| Import Data | This button is available if the dialog was opened using the Edit option. Click the button and the Import Non-Linear Material Data dialog opens to enable you to import the non-linear data file (*.csv format). |
| Plot data | Generate a graph of the raw material data. If the Ramberg-Osgood coefficients have been calculated from this data, the graph generated from the Ramberg-Osgood equation will also be plotted. |
| Edit test information | Details about the material test procedures are viewed in a new dialog. |
| Ramberg-Osgood (Tension) - Isotropic | These coefficients are calculated from the raw data in the Stress-Strain (Tension) table, when you click Calculate Mechanical Models. |
| Calculate Mechanical Models | Click this button and data from the Stress-Strain (Tension) table is used to calculate the Ramberg-Osgood coefficients. Each unique set of temperature, relative humidity and strain rate will generate a line in the table, provided there is enough data available. |
| Edit test information | Opens a dialog box that outlines the source date and method of testing to determine the Ramberg-Osgood parameters |
Ramberg-Osgood (Tension) - Isotropic table
| Data | Explanation |
|---|---|
| Sigma Zero | The stress level at which plastic strain becomes dominant. |
| n | Ramberg-Osgood curve shape parameter |
| Alpha | Directionality influence constant. A measure of the proportion of fibers in a given direction. |
| Beta | Directionality influence constant. A measure of the proportion of fibers in a given direction. |
| Eig | The maximum allowable effective stress. This value is based on the rupture stress levels of the material at 0º, 45º and 90º of the fiber orientation. |
| Matrix Modulus | The uniaxial stiffness (force per unit area) of the plastic matrix constituent material. |
| Matrix Poisson's Ratio | The ratio of lateral contraction to uniaxial elongation of the matrix constituent material. |
| Fiber Modulus | The uniaxial stiffness (force per unit area) of the fiber constituent material. |
| Fiber Poisson's Ratio | The ratio of lateral contraction to uniaxial elongation of the fiber constituent material. |
| Maximum Von Misses matrix stress at failure | The highest point obtained on a stress-strain curve. |
| Temperature | The temperature at which the material was tested. |
| Relative humidity | The relative humidity at which the material was tested. |
| Strain rate | The strain rate at which the material was tested. |