Week - 10 Hyperelastic Material Models

Week - 10 Hyperelastic Material Models

Aim:-

To calculate the Mooney Rivlin and Ogden material constants and compare both using stress-strain data from a Dogbone specimen tensile test with 100 percent strain. The given data is the engineering stress strain in MPa/(mm/mm). The comparison should be shown from the d3hsp file and using simulation.

Procedure:-

1. convert all Units in

Density;- 1100 kg/m3 or 0.00109 g/mm3

Poisson Ratio: -0.4999

100% strain=change in length/ original lenth=145mm

To solve this hyperplastic material, we use below mentioned material cards

*MAT_077_h *MAT_HYPERELASTIC_RUBBER

*MAT_077_o *MAT_OGDEN_RUBBER

If we will use MAT_077_h which represents Mooney Rivlin's constitutive model and Ogden's rubber model from 2 to 3 and find the material constant for each order. We can import a Load curve (experimental data value) and set SGL, SW, and ST parameters as 2 if the load curve is stress vs strain data.

The load curve is stress vs strain data.

*MAT_077_h *MAT_HYPERELASTIC_RUBBER

For ‘” N’” value change

EQ.1 is Mooney Rivlin's constitutive

EQ2 &EQ3 are Ogden material constants

Remaining steps same for week 9 steps.

Run the file.

The values of extension (=stretch ratio) and true stress were also copied from the d3hsp files to Excel and were converted to engineering stress and engineering strain using the following equations:

Engineering strain = Stretch - 1

Engineering stress = True stress/stretch

N=1

Fit to Mooney-Rivlin material ID= 1

(See message file for fit data formatted for plotting.)

Mooney constant c1 = 0.1768E+00

Mooney constant c2 = 0.1474E+00

load curve # 3

N=2

*MAT_HYPERELASTIC_RUBBER & OGDEN_RUBBER PID=1

Fit to General Hyperelastic material ID= 1

Hyperelastic Constant C10= 0.2595E+00

Hyperelastic Constant C01= 0.4594E-01

Hyperelastic Constant C11= -0.2092E-01

Hyperelastic Constant C20= 0.2914E-02

Hyperelastic Constant C02= 0.1016E-02

load curve # 3

N=3

*MAT_HYPERELASTIC_RUBBER & OGDEN_RUBBER PID=1

Fit to General Hyperelastic material ID= 1

Hyperelastic Constant C10= 0.2611E+00

Hyperelastic Constant C01= 0.4420E-01

Hyperelastic Constant C11= -0.6074E-02

Hyperelastic Constant C20= -0.2667E-02

Hyperelastic Constant C02= -0.9968E-02

Hyperelastic Constant C30= 0.1565E-03