bedyhope
Mechanical
- Sep 6, 2013
- 6
Hi guys
I am trying to simulate a tensile test beyond necking to validate the Stress-strain curve through the comparison of numerical and experimental Load-Displacement curves. Due to the symmetry, I model one eight of flat dog bone specimen, the boundary conditions are shown in the figure below. I gave density, young’s modulus, poison ratio, and point-wise true stress-plastic strain curve as the mechanical material properties. Also I have selected nonlinear geometry (NLGEOM)option to account for large deformation, yield function criterion as Von Mises and Hardening rule as isotropic. I have solved the problem , and got the load (from sum of nodal reaction force (RF) at the plane of applied displacement multiplied by 4), at the same time I obtain numerical displacement of a node that distanced 25 mm (half of gage length) from the fixed edge (multiplied by 2).
My problem is that, when I compared Experimental and Numerical load-displacement I found that, the Numerical load-displacement corresponds very well to the Experimental one just little beyond the necking point as shown in the figure below. I tried to adjust the material beyond necking and also i used fine mesh to get better correspondence but the problem still the same.
If anyone wants to see the input file I can up load it.
Please if someone has a solution or hint let me know
I am trying to simulate a tensile test beyond necking to validate the Stress-strain curve through the comparison of numerical and experimental Load-Displacement curves. Due to the symmetry, I model one eight of flat dog bone specimen, the boundary conditions are shown in the figure below. I gave density, young’s modulus, poison ratio, and point-wise true stress-plastic strain curve as the mechanical material properties. Also I have selected nonlinear geometry (NLGEOM)option to account for large deformation, yield function criterion as Von Mises and Hardening rule as isotropic. I have solved the problem , and got the load (from sum of nodal reaction force (RF) at the plane of applied displacement multiplied by 4), at the same time I obtain numerical displacement of a node that distanced 25 mm (half of gage length) from the fixed edge (multiplied by 2).
My problem is that, when I compared Experimental and Numerical load-displacement I found that, the Numerical load-displacement corresponds very well to the Experimental one just little beyond the necking point as shown in the figure below. I tried to adjust the material beyond necking and also i used fine mesh to get better correspondence but the problem still the same.
If anyone wants to see the input file I can up load it.
Please if someone has a solution or hint let me know