Hi
I am working on the seismic response of a single pile in sand.
The soil model is SANISAND04 proposed by Manzari and Dafalias.
There is one problem when I try to simulate the selfweight application step.
I want to assign a K0 value equal to 1sin(phi), phi is soil friction angle.
Originally we can achieve this by changing the analysis to elastic and assign different bulk modulus and shear modulus to give certain Poisson's ratio.
But for SANISADN, it seems I can't assign the bulk and shear modulus as UCSD model.
Does anyone know how to achieve this?
Many thanks,
Huan
How to setup K0 value in gravity step for SANISAND model

 Posts: 37
 Joined: Wed Jul 24, 2019 11:10 am
Re: How to setup K0 value in gravity step for SANISAND model
Hi,
You cannot assign a bulk modulus to the ManzariDafalis material, but you can set the following parameters so it should be fine for you:
You cannot assign a bulk modulus to the ManzariDafalis material, but you can set the following parameters so it should be fine for you:
 "materialState"
 0 = elastic
 1 = plastic
 "IntegrationScheme"
 5 = Forward Euler
 1 = Modified Euler with error control
 3 = Runge Kutta 4th order
 9 = Forward Euler constraining maximum strain increment
 7 = Modified Euler constraining maximum strain increment
 8 = RungeKutta 4th order constraining maximum strain increment
 4 = Forward Euler constraining maximum energy increment
 0 = Modified Euler constraining maximum energy increment
 6 = RungeKutta 4th order constraining maximum energy increment
 "Jacobian"
 0: Finite Difference Jacobian
 1: Jacobian
 "ShearModulus" or "refShearModulus"
 "poissonRatio"
 "voidRatio"
 Create a new selection set, and select all the solid parts of your model you want to assign the parameter to.
 Create a new Analysis Step "Misc_commands.parameter"
 In SelectionSets add the selection set created in step 1
 In Type choose element
 In Specific object arguments put poissonRatio 1 (where 1 is the material Tag, so use the Tag of the material in your model. Note that this thing of specifing the material Tag is specific to the ManzariDafalias model, otherwise it won't work, while other material models do not require it, so poissonRation alone is enough).
 Repeat the previous steps for every parameter you want to define
 Create a new Asnalysis Step "Misc_commands.updateParameter".
 In parameter add the parameter created in step 2
 In newVal put the new value of the parameter, so that it will be updated
 Repeat the previous steps to update again this parameter to a new value, or to update other parameters
Re: How to setup K0 value in gravity step for SANISAND model
Hi MassimoPetracca,
Great thanks.
Very detailed reply. It's very helpful.
Many thanks,
Huan
Great thanks.
Very detailed reply. It's very helpful.
Many thanks,
Huan