Additive manufacturing is such a broad category, ranging from laser sintering to fdm printing which vary wildly in material properties depending on inputs such as infill ratio, print orientation, layer height and more.

Does anyone know what assumptions were made in the material properties within this section? or even better where this data was pulled from? All I can seem to find is that it is "sample data representative of XXX material" which is not very helpful!

Thanks in advance!

]]>I am doing a project on ANSYS using wood, an orthotropic material. I have calculated the poissons ratios etc for implementing into a material, but ANSYS comes up with this error;

What I don't understand is how I can reduce the poissons ratio when it is dependent on the Youngs and Shear modulus. How can I fix it and make my material work? Any help is greatly appreciated! I have also attached my material properties as I am trying to set them up below;

I hope this makes sense!

Emily

]]>I have attached a photo of my work for your reference. please I need your help As soon as possible

Thanks In Advance

]]>But none for cylindrical Structures. I would like to know if it is possible to create a new polar coordinate system in the material library to define the chracteristics or if there is another idea.

Thanks for your support.

]]>Is there a way to define time varying quantities of thermal conductivity for a transient thermal?

I'm trying to solve a transient thermal problem, where in I knew the time variation of conductivities a priori. Basically, i was doing a multiple solve, and a each step i was using the MPDELE, and then try to redefine the material at a given time using MPDATA.

The solver triggered a warning that ' changing the material property during solution is a 'non-standard way'. Is it a correct way to define time varying quantities of a thermal- material property?

May i know if there any other standard way to define it.

Below is the script i tried to come up with

FINISH

/CLEAR,NOSTART

/PREP7

LENGTH=2e-03 ! 2*LENGTH, mm

HEIGHT=LENGTH/100 ! HEIGHT, mm

THICK=HEIGHT

esize=HEIGHT

area=HEIGHT*THICK

kxx_1 = 5.000000000E-03 ! VALUE AT initial time, t=0

cx_1 = 4.039360000E-02 ! VALUE AT initial time, t=0

t1= 358.000 ! inital temperature

mptemp,1,t1

mpdata,KXX,1,1,kxx_1

mpdata,C,1,1,cx_1

ET,1,LINK33

R,1,area ! AREA

k,1,-0.5*LENGTH

k,2, 0.0

k,3, 0.5*LENGTH

l,1,2

l,2,3

lglue,1,2

lesize,all,esize

type,1

real,1

mat,1

lmesh,all

esel,s,type,,1

nsle,r

IC,all,temp,1

allsel,all,all

d,node(-0.5*LENGTH,0,0),temp,0

d,node(0.5*LENGTH,0,0),temp,0

FINISH

/SOLU,

ANTYPE,TRANS

KBC,0

nleng=40

deltime=2

*dim,dxx_1,array,nleng,1

*dim,ccstinter_1,array,nleng,1

*do,tt,1,40

currtime=deltime*tt

curr_temp=(273+85)+2*deltime*(tt)

dxx_1(tt,1)=D0_1*exp((-ED_1)/(R*curr_temp))

ccstinter_1(tt,1)=RH*S0_1*P0_1*exp((ES_1-EVP_1)/(R*curr_temp))

mptemp,1,0

mpdele,kxx,1

mpdata,kxx,1,,dxx_1(tt,1)

mpdele,c,1

mpdata,c,1,,ccstinter_1(tt,1)

allsel,all,all

OUTRES,ALL,ALL

TIME,currtime

NSUBS,1,1,1

solve

*enddo

FINISH

]]>I am modeling non linear concrete and want to use **drucker prager model**. I am very confused how to get these values. Please help me. Compressive strength of concrete is 3940 psi. Thanks in advance.

Thanks,

Regards,

ADEEL

]]>kind Regards,

]]>I have glued the three volumes ie substrate, layer1,layer2 as shown in figure. Then, i am trying to kill the layer2 to simulate the deposition of layer1. At last, i will activate the layer2 and apply the load on the layer2.

Am i thinking in the right direction?

There are 43 loadsteps in each layer so i am using do loop but, i am getting following error,

Where do i place 'ekill' command in my code??

i am attaching the snapshot of the APDL script after meshing.

Kind Regard,

]]>Is there any reason to use the classical hyperelastic constitutive models (neo-hookean, blatz-ko, arruda-boyce, etc) if I have, or can acquire, test data from a set of samples and want to use the Response Function model?

In addition to that, lets say my Instron output provides 13,000 stress/strain data points and I want to upload that as a CSV into the uniaxial tension test data, will the number of data points affect my overall solution time? Is there a limit to the amount of input data?

Last question: If I have a case of multiaxial loading in my model, which data sets (compression, shear, volumetric, biaxial etc) are recommended to fully define the stress strain response?

Thanks for your help! These questions are not related to a specific working analysis, I am just planning how I may use Response Function in the future.

]]>May I ask a question regarding the capabilities of the Ansys Material Designer? I have been working on research about natural fibre epoxy composite material. I want to simulate its material behaviour. I'm planning to use a user-defined RVE to get the mechanical properties like the youngs modulus and shear modulus. I have fabricated a composite lamina. I'm planning to subject it to an x-ray process to get the actual geometry(inner and outer surface, including voids) of the lamina. The x-ray process will generate a 3D model in CAD software. Would it be possible to input this 3D geometry (micro-scale) in the Material designer? I would appreciate it if you could give me some advice regarding this.

Thank you.

]]>I am currently using ANSYS 19.0 to model using additive manufacturing extension but, the powder bed fusion process is not having laser power as one of its build parameters for me to vary it. Is there a way for me to get an extension with laser power and also can I analyse the dimension of the molten track during the simulation process?

]]>I was wondering if anybody has used agilus 30,which is a additive manufacturing (poly jet) rubber like elastic material, in any simulations. How can I use this material in Ansys accurately? I was wondering If anybody could help me out with the material data, as I don't have the option to material test it and the data given by the proprietor isn't enough.

]]>I'm trying to model the Expanded Polystyrene (EPS) Foam used for bicycle helmets. I've been using the ANSYS built in Foam, Expanded Polystyrene material provided by GRANTA Materials Data for Simulation. While this material has worked, I'm concerned that it doesn't seem to exhibit any plastic deformation. I'm hoping to introduce crushability of the foam.

I have tried incorporating EPS stress-strain data from research papers into the built-in model as uniaxial test data, but I'm still not see any plastic deformation. I believe this is because I'm not including plastic failure models and I'm wondering if there are any resources in this area?

I have tried using bilinear kinematic hardening properties, but the material fails (this may be due to incorrect values used). Specifically, I'm wondering what plasticity models should be included in the material in order to see a plastic deformation when the helmet impacts a surface?

Thank you

]]>for my master thesis I simulate a Timber-Concrete-Composite Beam. Therefore, I should consider cracks in the tension zone of the concrete slab. First idea was to use a concrete Drucker-Prager softening material model (see picture 1).

I used a patch-test to verify the material model. Unfortunatly, the stress-strain curves under compression and tension are not as I imagined (see picture 2). I attached self-drawn stress-strain curves to show you how they should look like (see picture 3).

Furthermore, there are Solver-Pivot Warnings during the patch-tests, howerver, the calculation works. But for a simply supported beam the calculation doesn't converge. (I have already defined substeps.)

Can someone help me please? Did I define the Drucker-Prager softening wrong?

Thanks in advance!

Lea

I am trying to model the cracking behaviour of unreinforced concrete or screed. I am using the Menetrey-Willam-Model and according to the underlying crack-band model, I need to define a tension softening behavior via the yield function Omega_t (curve of tensile relative stress over plastic strain kappa) without losing the objectivity of the model. I can either use exponential softening or linear softening. In the case of exponential softening the parameters fracture energy G_ft and residual relative stress Omega_tr have to be defined. In linear softening, the parameters are again the residual relative stress Omega_t and the plastic strain limit kappa_tr.

Now my question concerns the mesh dependency: In the Menetrey-Willam documentation in the Ansys Help there is a parameter "effective element length" to "overcome mesh-depenedent softening behavior". If I use exponential softening, the effective element length influences the model obviously through the yield function (equation 4-47 in the documentation). But in linear softening I have to define the yield function directly through the parameter of the plastic strain limit kappa_tr.

So the effective element length doesn't influence the material model in case of linear softening, does it? So the linear softening behavior is fully mesh-dependent, isn't it?

Or is there another way, in which the effective element length influences the material behavior in the case of linear softening?

Thank you in adavance for your help!

Kind regards

Katharina

]]>I am new to learn Ansys. I am trying to solve benchmark problems step by step. At this moment I am trying this problem. i am trying to solve it based on 3D. I am trying to create an O-grid of hexahedral elements. I can't create it with the presence of the beam. Can Someone guide me to solve the problem?

]]>I'm trying to model a PVC cable sheath with hyperelastic material behaviour and therefore, among other things, I conducted a uniaxial compression test. I read/heard that test data from uniaxial compression and biaxial tension are interchangable with regard to using it for curve fitting in combination with the Mooney-Rivlin model f.e.

If I put in the data as uniaxial compression data the curve fitting won't acknowledge it at all (it seems, that processing uniaxial compression data is not supported for hyperelastic models - at least, that's what I took away from the ansyshelp page).

So my question is: Do I just take the data of the compression test and put it in as biaxial tension? If not, what's the right way to do it?

Cheers,

Sebastian

]]>I have recently installed the latest student version of Ansys student mechanical 2020 R2. I want to conduct a static structural simulation on the PLA material. But, despite being searching for a long time, I don't be able to find it out. Kindly, anyone helps me out in this regard.

Look forward to hearing back from you.

Thanks !

]]>I'm trying to model a time dependent thermal conductivity material by specifying thermal conductivity using TBFIELD command. The model has 3 link elements and I solved transient run for 6 sub-steps.

After looking the output of the stiffness matrix for every substep, I see that they are not changing.

I'm not sure if my input for TBFIELD is correct, although the output echo of the command didn't give any errors.

I have attached the input to reproduce the issue. Could you please take a look into this issue and let me know if time dependent KXX is correctly accounted.

Thanks

Vinod

I would like to depict the following:

I have a material (insulation material) that is subjected to thermal transient loads. Material 1 should be used while the cross-section is heating. At some point, the external thermal stress decreases. Due to the inertia of the insulation material, some areas heat up even further when the external temperature begins to decrease, while the edge areas of the cross section cool down. I would like to start by looking at only one cycle, i.e. Warm up and cool down within one simulation.

I would like to change the material in WB via an APDL command with MPCHG. It should be checked at every time step for each individual element whether it is heating up or cooling down. When it cools down, the material change from "1" to "2" should take place for the respective element. Every element in the body checks this for itself.

What I've done so far in ANSYS WB:

In the “Technical data” in WB, I have only defined two materials and named them “1” and “2”.

Then I go into the model:

In the equation solver (/ Solu) in the structure tree I have inserted

numsb=200 ! number of steps

esel,s,mat,,1 ! I want to select my material „1“.

*get,n_max,node,,num,max ! I want to select all nodes.

*dim,n_temp_old,,n_anz ! Define arrays

*dim,n_temp_new,,n_anz

*dim,dif,,n_anz

*vfill,n_temp_alt,data,0 ! old temperature is = 0 at the beginning

alls

solve ! First calculation

*do,i,1,numsb ! Loop over the calculation steps

esel,s,mat,,??? ! Select material that i want to check, where do I have to define the material. Does the access work on „technical data“?

nsle ! Select nodes of the material

*voper,dif,n_temp_old,sub,n_temp_new ! create temperature difference

cm,temp,node ! none nodes should be selected

*do,i,1,n_max

*if,dif(i),lt,0 ! if difference is negatice

nsel,a,,,i ! then the node is additional selected

*endif

*enddo

esln,,1 ! If all nodes are selected the element changes its material

mpchg,2 ! change to material “2”

cm,n_chg%i%,node ! for every step a new component is created

cm,e_chg%i%,elem

*vfun,n_temp_old,copy,n_temp_new ! new temperature becomes the old temperature for the next calculation step

solve ! calculation of the current step

*enddo

cmwrite,komponenten,cm ! this is supposed to be able to import the resulting components after the calculation as "Named Selection" in Mechanical - but how?

fini

The commands take place exclusively with an equation solver. Otherwise I have no APDL commands or changes to the settings in the preprocessor or postprocessor. When I perform the calculation with the APDL commands, no error messages appear. But it makes no difference whether I suppress the orders or not. I always get the same results. regards Benna

The circles on the geometry surface represent the electrodes and I drawn them by using FaceSplit and I don't know if this is the way to represent the electrodes and how the load is distributed when applying load to it. I also tried to do static simulation by applying pressure in both side of the elastomer and I notice that both pressures are not perpendicular to each other, and the pressure is not distributed evenly, any ideas how I can solve this?

I also added in the zip file a photo of the elastomer and it is fixed by a rigid frame from the top and bottom, in ANSYS I fixed all the four side of the elastomer. I really do not know how to start I have tried to look for any reference that can help but I cant find. I don not know how I can apply cyclic voltages under different frequencies on to my elastomer. By the way, I was using Sine wave to apply the load onto the elastomer during the experimental test .

What I want to achieve from the simulation is: finding the deformation of the elastomer under different voltages and frequencies. And I don't know if it is really possible to preform this kind of simulation with the student version. I am using ANSYS 2020 R2.

Any help will be highly appreciated🙏

]]>Hello friends

I just want to apologize for my English. My problem is the following, I got the data from the Serge Ferrari polymer membrane with a fabric backing:

Warp modulus, Ew = 900 kN/m

Fill modulus, Ef = 930 kN/m

Poisson’s ratio warp-fill, νw-f = 0.68

Poisson’s ratio fill-warp, νf-w = 0.48

При этом я не могу задать эти данные так как их нужно задать в Па (kN/m2). Как можно задать такие значения в Ansys WB или их нужно преобразовать?

]]>If it is possible, what is the material's data? If not, why?

]]>I wanted to run a static structural simulation within the elastic limit of a polycarbonate based material- Makrolon. It is a highly non linear material, within the yield point. Please help in choosing the best material model to work with the same. The aim is to calculate the maximum load that can be applied below yield limit, which is 66 MPa (23 Deg C). All i have is stress strain data, which alone cannot be used in hyperplastic model (as I know). Is it possible to use multilinear model for the same? Thanks.

I am trying to define a Polymer material based on tensile test data. my main issue is the polymer enters the plastic zone after 70% strain.

I am using this polymer in an application that works only in the elastic zone of the material (entering the plastic zone for my application means failure).

I used Yeoh 3rd order (hyperelastic model) to define only the elastic part of the curve ( less than 70% strain) and my simulation ( using static analysis in ansys work bench) works well, is this right? if not I would appreciate it if you suggest the right method for defining the material.

I checked the forum and I understood that Hyperelastic materials should not be used with plastic materials.

I uploaded the tensile test figure for the polymer.

I was trying to model cyclic plasticity using chaboche Kinematic hardening model. I noticed that when you input a chaboche Kinematic hardening model a curve fitting option becomes available. When you include the curve fitting option a uniaxial plastic strain test data input area where it says add experimental data becomes available. Can anyone please explain to me how I can input the uniaxial plastic strain test data and how I can get the chaboche parameters?

Thanks.

The circles on the geometry surface represent the electrodes and I drawn them by using FaceSplit and I don't know if this is the way to represent the electrodes and how the load is distributed when applying load to it. I also tried to do static simulation by applying pressure in both side of the elastomer and I notice that both pressures are not perpendicular to each other, and the pressure is not distributed evenly, any ideas how I can solve this?

I also added in the zip file a photo of the elastomer and it is fixed by a rigid frame from the top and bottom, in ANSYS I fixed all the four side of the elastomer. I really do not know how to start I have tried to look for any reference that can help but I cant find. I don not know how I can apply cyclic voltages under different frequencies on to my elastomer. By the way, I was using Sine wave to apply the load onto the elastomer during the experimental test .

What I want to achieve from the simulation is: finding the deformation of the elastomer under different voltages and frequencies. And I don't know if it is really possible to preform this kind of simulation with the student version. I am using ANSYS 2020 R2.

Any help will be highly appreciated🙏

]]>