Hi Dr. Jorgen,

I've couple of quick questions:

1) I am planning to use ABAQUS 2D shell formulation (S4R) to estimate 3D state of stress. I've read several articles to estimate the transverse shear stresses once the in-plane stresses are known by integrating the 3D equilibrium equations. This is, of course, easily done, if we have closed form solutions for in-plane stresses:

sigma_xz,z = - (sigma_xx,x + sigma_xy,y)

sigma_yz,z = - (sigma_xy,x + sigma_yy,y)

How do I estimate transverse shear stresses using ABAUAS VUMAT, when I only know the in-plane stresses at one integration point in the element (in case of S4R) in VUMAT?

2) In my analysis, I will use progressive failure analysis, where transverse stiffness cannot be kept constant in the analysis (I read in ABAQUS manual, we cannot change the transverse stiffness. Is there any possibility to vary transverse stiffness in case of shell elements?

Thank you for your help,

Nagesh

I've couple of quick questions:

1) I am planning to use ABAQUS 2D shell formulation (S4R) to estimate 3D state of stress. I've read several articles to estimate the transverse shear stresses once the in-plane stresses are known by integrating the 3D equilibrium equations. This is, of course, easily done, if we have closed form solutions for in-plane stresses:

sigma_xz,z = - (sigma_xx,x + sigma_xy,y)

sigma_yz,z = - (sigma_xy,x + sigma_yy,y)

How do I estimate transverse shear stresses using ABAUAS VUMAT, when I only know the in-plane stresses at one integration point in the element (in case of S4R) in VUMAT?

2) In my analysis, I will use progressive failure analysis, where transverse stiffness cannot be kept constant in the analysis (I read in ABAQUS manual, we cannot change the transverse stiffness. Is there any possibility to vary transverse stiffness in case of shell elements?

Thank you for your help,

Nagesh

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