Science topic

# Plasticity - Science topic

In physics and materials science, plasticity describes the deformation of a material undergoing non-reversible changes of shape in response to applied forces. For example, a solid piece of metal being bent or pounded into a new shape displays plasticity as permanent changes occur within the material itself. In engineering, the transition from elastic behavior to plastic behavior is called yield.

Questions related to Plasticity

Hi all,

I have a question about the simulation of uniaxial tensile test of sheet metal. When I adopted the GTN Porous fracture model (it was embedded into the ABAQUS software) to simulate the uniaxial tensile test of sheet metal, I found that the simulation results vary with degree of the input material plasticity data. When I input material plasticity data upto 4 (extrapolated by swift law), the simulative displacement obviously exceeded the experimental displacement. And When I input material plasticity data upto 0.123, the simulative displacement Roughly equal to the experimental displacement. I can't think through the reasons behind it, and Can someone explain this?

Thanks in advance for any advice!

Hello community,

I'm trying to simulate cracks with cohesive elements (in Abaqus), but I would like to reproduce reality as much as possible. Therefore, I would first like to have elastic behavior after which plasticity comes which brings plastic strain. Then after some accumulated plastic strain, I would like an opening of cohesive elements like a formation of a crack.

I've started examining this case with perfect plasticity or with a slight hardening, I've also tried with proper hardening but can not get a cohesive zone. All dissipation goes in plastic flow.

Do you have any advice on what to do to get first some plastic flow (like in reality) and the formation of the cohesive zone that finally breaks like a genuine crack?

Material is steel:

E: 200000 Poisson: 0.3

Plasticity starts at 250 (perfect plasticity)

Cohesive zone_ Traction separation law

Elastic properties 6000000, 6000000, 6000000

Damage int: ????

Damage evolution0.0001

With Damage Initiation, I was trying different things 250 like where plasticity starts, or with hardening, and then put initiation on 251 or 255 and different combinations. Nothing works.

Thanks a lot in advance,

Domagoj

I have seen different visual observation techniques written in a few papers (e.g.: Serrated plastic flow by P. Rodriguez) to identify the type of serration (Type A: sudden plastic flow followed by a drop, Type B: oscillations about general level, Type C: yield drops below the general level of stress-strain curve). However, not all serrations are perfectly shaped. So, identifying serration through visual observation only becomes difficult. Is there any mathematical model or any other way by which the serrations can be characterized?

Hi all,

I am trying to model a joint connecting 1D BEAM elements using ABAQUS connector element with the joint behaviour obtained in a separate 3D analysis. For example, I have a joint modelled in 3D SHELL element and after analysing this joint I obtained a moment-rotation relationship of this 3D joint. This moment-rotation relationship is then assigned to an ABAQUS connector element connecting the 1D BEAM elements in the 1D BEAM model.

My question is how do you correctly define the elastic and plastic range of behaviour in ABAQUS connector element?

1. Is the Elastic behaviour option only for the elastic range of my moment-rotation relationship or do I have to define the full elastic-plastic range in this behaviour option? If the latter is correct, I then need to tell ABAQUS in the Plastic behaviour option from what moment onwards in the full elastic-plastic range defined in the Elastic behaviour option where it should behave plastically?

2. I tried to define negative values in the Plastic behaviour option as my joint can have load reversal, however, it keeps giving me error. Is the Plastic behaviour option only allow positive values? If so is that mean ABAQUS assumed the onset of plasticity occurs at the absolute value of the number I specified for both directions? What if the onset of plasticity of my joint is different in 2 loading directions? Do I need 2 separate Plasticity behaviour options (1 for each direction) for it to work?

I know this is a long question, hopefully, there is someone out there who read through this and could provide me with some direction.

Many thanks,

Heng

concrete damage plasticity model in ABAQUS of reactive powder concrete containing steel fibers

For thermal contact conductance estimation, selection of plastic or elastic deformation models is based on plasticity index. At lower pressure at the interface, the deformation of surfaces may be elastic even though the plasticity index is greater than 1. Plasticity index will not account for pressure.

I am running the tensile experiment (polymer material) in Abaqus explicit with the Ramberg model. But the solution exists with an error. It's showing "The keyword is not existed in explicit".

Then how I give the plasticity parameters explicit.

Dear Researcher,

Suppose there is two concentric hollow cylinder and by some metal forming process the inner cylinder is plastically fitted with the outer cylinder in such a way that there is sufficient contact pressure is generated between the two cylinder interface and they are plastically shrink fitted.

Now this assembly place in a high temperature and high pressure environment and due to creep there is decrease in contact pressure.

Can anybody suggest me how to modelled this whole process in COMSOL so that we can find out the decrease in contact pressure with time.

I also have to modelled that if there is a very small hole (gap) at the interface of two cylinder then how the diameter of this hole is changes with time?

If someone using other FEA software or code then please suggest?

Thanks for your valuable suggestions.

Shyam Kishor

Regular polygons of trigonal and hexagonal symmetry are used as yield criteria in theory of plasticity:

References for regular icositetragon (24-gon) as yield criterion are sought for a systematization of yield and strength criteria.

Only temperature dependence is to be considered but I can't find the way to enter the working temperature or is it defined in the predefined field?

Dear Researcher,

Please help me to find CDP parameters of Ultra High Performance Concrete for ABAQUS input. If you have any excel sheet or previous study, kindly send it to me.

Looking forward to hearing from you.

Is it necessary to give Temperature dependency material properties, like
Elasticity and plasticity while modeling in ABAQUS?
When we are using Subroutine- USDFLD GETVRM (TEMP) to get Nodal point temperature in output.

I am an M.Tech structural engineering student working on the project ' Numerical analysis of Kath-kuni architecture ( a common masonry typology ) in Himachal Pradesh region of India subjected to earthquake loading in ABAQUS software' . The question of concern is that I am finding it difficult to input plasticity parameters for timber/ wood material that I have used in my model even after searching in various research papers. I have got only elasticity parameters and wood being an orthotropic material requires plasticity parameters and a plasticity damage model to be defined in order to understand the actual material behavior in ABAQUS software. So, kindly help me in finding the plastic properties and a damage model for timber, it would be very helpful to proceed in my current project.

Thanks and regards

Dear all,

I am looking for a research work that implemented an uncertainty or statistical framework to study the impact of the geometric parameters on the fracture response.

I appreciate any help.

Thank you in advance,

Moj Ab

hello, i am modelling a RC slab in Abaqus, the slab is supposed to fail in punching shear which is a sudden failure. i defined the nonlinear behaviour of concrete using concrete damage plasticity model, but i can't reach the desired results as the failure is not sudden (load-deflection curve shows that the load is decreasing gradually after reaching its max value, an it's supposed to be a rapid degradation not a gradual one). as well as, i know that whenever i there is a localization of cracks somewhere in the model (which is the case in my model), using concrete damage placticity model may make the results mesh-dependant. so what should i do? should i use GFI? or do i need to use concrete smeared crack model to simulate the nonlinear behaviour of concrete instead of using concrete damage placticity model?

thank you in advance.

As stated above. I have a group of trees from two different environments that consists of sets of half-siblings and I'd like to test their plasticity to a climate change variable. Is this a valid approach since they are only expected to share one quarter of their genes? Thank you!

For a RCC frame cyclic load analysis in ABAQUS, Materials designed as linear CDP, while submitting the job it shows the warning _

"The strain increment is so large that the program will not attempt the plasticity calculation at 4956 points"

then after 5 unsuccessful attempts shows the error_

"Time increment required is less than the minimum specified"

The simulation was under "General Static"

Incrementations, Error, loading Amplitude, Amplitude plot is attached bellow as .png file.

Please tell me how to overcome the problem that, I can run the simulation smoothly.

Hello everyone,

I am quite new to Abaqus. I am trying to analyze a 3D model of a laterally loaded pile where the pile is modelled as a rigid body with a reference point at a height e from the top of pile and the soil is modelled with Mohr Coulomb plasticity model. In order to obtain the load-displacement plot of the pile a displacement boundary condition is applied at the reference point. As the value of cohesion is very low (0.1kPa), Abaqus explicit solver is used to solve the problem. The energy diagram for the whole model I am getting seems to be incorrect. Also, I am not being able to find a technique to obtain the load required to plot the load-displacement plot. I tried to get the load by collecting all the reaction forces in the direction of loading (x-dir) in all the support.

Is my methodology correct? Also, can anyone please provide any assistance regarding the nature of he energy plot of the model?

Any suggestion will be appreciated.

I have attached the .inp file for anyone's reference.

While analysis I am getting the following warnings;

*Integration and section point output variables will not be output for deformable elements that are declared as rigid using the *rigid body option*

*Output request peeqvavg is not available for element type c3d8r*

*Output request sequt is not available for the material for element type c3d8r*

*The option *boundary,type=displacement has been used; check status file between steps for warnings on any jumps prescribed across the steps in displacement values of translational dof. For rotational dof make sure that there are no such jumps. All jumps in displacements across steps are ignored*

*Step 1, Increment 38: 1 material point(s) failed to converge in the material constitutive routines.*

I'm trying to simulate the formation of segmented chips while performing turning of Ti6Al4V, I don't know why my mesh is getting distorted eventhough I'm using a fine one!!!

My wp consists of 3 zones, 1) uncut chip thickness zone where segmented chips are supposed to form, 2) Thin sacrificial layer, 3) Machined zone which results when chips have been formed. For 1 & 3 I've only applied material with JC plasticity no JC damage, for 2 I've assigned JC damge with evolution as well.

Please help.

Hello! can someone help me please?

I'm simulating a tensile test with flat specimen in Abaqus explicit using JC plasticity and JC failure criterion. I need the

**strainxstress curve**, a need the total strain not only the plastic strain, but in the "creat xy data --> ODB field output" doesn't appear the E. But I have selected it in the "Field Output Request"During scratch test, the tip applies a force on the thin film surface and tensile stresses are generated behind the tip contact zone. A stress field then subsequently generates inside the film. The film deforms plastically and elastically to respond. Does the substrate deform plastically as well even though the tip doesn't make contact with it directly?

I know that substrate can relieve the stress through plastic deformation during film growth.

But is it similar to the case like scratch or wear test ( apply addition load on the surface)

Does substrate deformation help to relieve the stress generated by scratch tip? If so, plastic deformation or elastic deformation dominates?

Can anyone kindly share your opinion on this please?

Hi all,

I am culturing primary hippocampal cells from P0 mice and would like to measure whether synaptic plasticity is altered after treatment with different compounds, using whole-cell patch clamp.

What are your favourite techniques/protocols for plasticity measurements in dissociated cell culture using whole-cell patch clamp or other techniques?

We have the options of spike-timing dependent plasticity, chemically-induced LTP, etc.

Thanks in advance,

Hannah

I want to simulate the plasticity for the Ti and its alloys with two phases (Alpha and Beta) in Abaqus. Now I have already created the microstructure model but unsure what properties I should assign to its two constituent phases, namely alpha and beta, as I only know the bulk material parameters (e.g., Ti-10Mn)?

Alpha and beta are part of Ti-8Mn; the only difference I see is that one will be HCP while the other the BCC structure, so how do I create such a material?

Elasticity, viscosity damping, horizontal seismic insulation, plasticity, and dynamics are the useful factors that increase the response of the structure to seismic shifts.

how each of these properties of the structure works?

what are the failure limits?

and finally what is the most useful property that the structure must have to react better to the earthquake.?

I am working on developing a micromechanical FE model for predicting kink-band formation in UD composites. To model matrix plasticity, which model, out of Concrete Damaged Plasticity and Drucker-Prager, is preferred? Any insights particularly on the differences between the two models will be really helpful.

Can the cyclic nanoindentation technique be used for analyzing the cyclic elasticity/plasticity/hardening/softening or viscoelastic properties of metallic materials? I could not find any research articles on the same (except for thin films!).

Thanking you in advance.

Siva

Hey everyone,

Which plasticity model is suitable for modeling 316L selective laser melted steel in miso and micro scale modelling? Is isotropic hardening is good for this type of materials? (I want to model the fracture in melt pools )

Thank you.

Hello all

I intend to obtain orientation changes in the rolling process under the theory of crystalline plasticity. What model can I use to simulate rolling under the theory of crystalline plasticity?

Best

Sina

I want to simulate the bulging of a circular thin steel plate due to fluid pressure and finally see the rupturing of it.

What is the best criteria to simulate the material properties in plasticity and damage for this type of problem in Abaqus software.

Material is SS316 or something like that which we have the uniaxial tensile test results. And has a 1mm thickness and 100mm diameter.

Loading is a simple progressive uniform pressure.

Thanks

Including the so-called kinematic hardening in phenomenological material models allows capturing the accumulation of plastic deformation in materials subjected to cyclic loadings. It determines that the size of the "elastic domain" in the deviatoric stress space remains constant and that upon plastic yielding, the domain is simply translated.

In largely deformed materials in tension, the kinematic hardening may result in a translation of the elastic domain to levels where the initial compression yield-limit becomes now a tensile stress value. This implies that upon unloading a plastically-deformed material (returning to zero loads), it may experience plastic deformation as well. My question is, is that physically possible? If yes, how can it be explained?

Hello all,

I am confused about the definition of ratcheting for polymers.

For metals, when the material is subjected to cyclic loading, ratcheting is a phenomenon where plastic deformation accumulates progressively with each cycle.

For polymers, plastic deformation certainly causes ratcheting. I found most papers mentioned plasticity or viscoplasticity for polymers' ratcheting. But can the ratcheting occur within the yield surface? Or can the ratcheting be induced by time-dependence or viscous?

Looking forward to anyone's reply to give me some thoughts.

Thanks.

Hey guys,

I am attempting to model the installation of a helical pile into sand using Abaqus CAE (explicit). I am using a CEL model with a rigid pile and Eulerian sand part.

Every time I run the job, the sand part 'explodes' and has very large deformations. I have attempted to rectify this problem via the following trials:

-assigning cohesion to the sand;

-applying a pressure to the sand;

-beginning the installation with the pile already penetrated into the sand part.

Through an exhaustive trial-and-error process, I found that I have solved the exploding sand problem by changing the 'hard' normal contact interaction to a 'linear' contact interaction. However now, the history outputs show no plasticity/plastic deformation! This is kindof important as I am interested in finding the installation disturbance effects of screw-pile installation.

Is anyone aware of what I can do to accurately/realistically model the installation disturbance effects of a screw-pile being installed into sand? I am happy to provide any more information as needed.

Thanks!

Dear community,

I would like to derive the formula for the calculation of the deflection of the plate at any point (see attached image).

I am looking into Timoshenko's Theory of Plates and Shells and also on xcalcs and I fail to understand how to derive the formulas. Would anyone be kind enough to help me with this?

For example, how can I use strain energy (V) minimization to get the deflection? How can I derive the strain energy equation and how can I solve it?

Any guidance for dummies is extremely appreciated.

Thank you very much for taking the time to read my post.

Best regards,

George K.

Please share any Example, Tutorial or any article related to CDPM. For a 3D Pushover analysis.

Thanking in anticipation!

Frequency determines the number of complete displacements of a body from the initial point of rest within the unit of time 1 sec The amplitude of oscillation is the metric magnitude of a periodic motion of a body that oscillates around its initial equilibrium position. The amplitude of the oscillation and the frequency determine the magnitude of the acceleration. The acceleration of a body falling to the ground is 9.81m / sec = 1g To measure the acceleration of the ground reaching below the base of the structure we use (g) eg constructions can withstand 0.50 g for a short time The magnitude of the earthquake is measured by the acceleration that will eventually reach below the base and not by the magnitude of the Richter scale itself. The acceleration that reaches below the base depends on the magnitude of the earthquake, the focal depth, the distance of the structure from the center of the earthquake and the soil conditions between the earthquake and the structure. Duration is called the event time of the earthquake. Acceleration and duration determine the disaster rate. A structure can withstand high acceleration (1/2 g) for a short time or vice versa low acceleration for a long time. The strength of the construction depends on the magnitude of the acceleration, the duration of the earthquake as well as the seismic damping mechanisms available. Each body has a specific frequency that oscillates and it depends on its height. When the ground frequency coincides to be the same as the construction frequency we have the tuning. During the tuning all the energy of the earthquake is transferred on the construction and if the construction does not have seismic damping mechanisms then the oscillation amplitude gradually increases over time, so the construction receives increasing seismic loads until it is destroyed. In today's seismic design, the inelastic displacement of the structures is considered inevitable and they try to mitigate the damage by using various seismic damping mechanisms. In addition to the above, there are too many unbalanced factors that can cause disaster and in most modern seismic structures. The factors that determine the seismic behavior of structures are numerous, and in part probable. 1) The direction of the earthquake is unknown. 2) the exact content of the seismic excitation frequencies is unknown. 3) duration unknown 4) acceleration unknown Even the maximum possible accelerations given by seismologists, and determine the coefficient of seismic design have a probability of exceeding, greater than 10%. The correlation of quantities such as "inertial stresses - damping forces - elastic forces - dynamic construction characteristics - construction ground interaction - forced ground motion" is non-linear and determines the response of structures to the earthquake. According to modern regulations, the seismic design of buildings is based on the requirements of competent cross-sectional design and plasticity. The inevitable inelastic behavior under strong seismic excitation is directed at selected elements and failure mechanisms. Poor design of the sections around the nodes and the limited plasticity of the elements lead to major failures I mentioned all of the above to understand that when a static study is signed the earthquake can destroy you along with the building its people and its contents. Nothing is certain with an earthquake, and this is because when some of the above factors, such as resonance, long duration and high acceleration, coincide, then the inelastic displacement will not be difficult to pass at a breaking point. Conclusion. Today's seismic design is uninterrupted because it can not control deformation. Seismic damping by different mechanisms may help in the smooth absorption of seismic energy, but there is no guarantee that the structure will stand upright. The quality of constructions and their safety is also a function of the economic situation of the countries, among other factors. Understandably, poor countries cannot be compared to countries with strict modern anti-seismic regulations. Here we see that there is a great need to change the seismic design. We need an anti-seismic design that controls deformations regardless of whether we have coordination, long seismic duration and high acceleration, as well as being accessible in poor countries. I believe that the method I propose (pre-tensioning + anchoring to the ground of all sides of the walls with diaphragm function) will increase the response of the structures and reduce the construction costs, because if the construction is stronger than we need then we remove reinforcing steel and bases and drop the cost.

I am working with DIANA and I'm going to conduct the analyze under reversed loading by using Menegotto Pinto plasticity model for reinforcement bar.

In the absence of experimental data, how can I find the parameters that are included in Menegotto Pinto plasticity model such as: initial tangent slope ratio, initial curvature parameters and all constant parameters (a1, a2, a3,a4).

Is there any explanation about all these parameters or someone may provide some information about?

All data for reinforcing steel that I have is Poisson ratio=0.3, yield stress=472MPa, and modulus of elasticity=214000

Thanks in advance.

I've to model the plastic behavior (Yield Stress vs Plastic Strain) of a polyimide material (Elas_Mod=2500MPa) in Abaqus. The engineering stress vs strain plot is shown as the 3 red curves. I've captured the curve corresponding to 23degC in Matlab, as can be seen in the blue plot. The plot starts from yield point stress = 69MPa. Next I convert this eng. stress and eng. strain to true stress and true strain using:

True_Stress = Eng_Stress*(1 + Eng_Strain)

True_Strain = log(1 + Eng_Strain)

The corresponding plot for True Stress vs True Strain is the green plot. Next I convert the true strain to logarithmic plastic strain using:

Log_Plastic_Strain = True_Strain - (True_Stress/Elas_Mod)

The first value of log plastic strain is changed to zero, representing the yield. The plot of true stress vs log plastic strain is the black plot. Here it can be seen that after a point, the plastic strain decreases with increasing true stress. So when assigning the plastic data in Abaqus, do I use only those points up to which the plastic strain increases and ignore the remaining points? Why does the true stress vs log plastic strain plot have decreasing strain trend which eventually moves towards negative values? Thank you for your time!

Greetings,

I'm studying structure changes in a 2D granular sample subjected to shear stress. I have captured the dynamics along time with a video camera and I have obtained particle positions for every frame of my videos through image processing. And my question is:

What kind of statistical or physical-mathematical tools can I employ in order to measure plasticity & elasticity degrees in the bidimensional granular structure?

Thank you in advance for your answer!

1. What is the

**difference**between hydrostatic and quasi-hydrostatic pressure?2. Are all SPD techniques providing this pressure?

As Zhilayev et al. mentioned, Multi-directional forging (MDF)

**not providing**quasi-hydrostatic condition in www.scientific.net/DDF.385.302Want to reduce the Hardness of TPU. As TPU comes in a granular form incorporating plasticizer is difficult. What methods can be used to incorporate plasticizer in TPU?

Can anybody help me to figure out plasticity values for stainless steel for Dynamic Explicit analysis in Abaqus ?

It doesn't matter about the stainless steel type and please be kind enough to let me know how to get those plasticity values and yield stress values which are coming under material properties...

Dear researchers

As you know, one of the challenges of using nonlinear procedures is to determine the behavior of plastic hinges of members with deformation controlled action that this behavior is assigned to the plastic hinge by a force-deformation curve and its relations using parameters modeling. various researches has shown that the uncertainties in these modeling parameters significantly affect the structural responses.

Also, the acceptance criteria of different performance levels relating to the mentioned force-deformation curve are needed for performance-based design of structures.

There are two questions now:

1- Are force-deformation curves presented in ASCE 41-13 suitable only for nonlinear static analysis (push over)? or also is applicable for nonlinear dynamic analysis?

2- Given that the acceptance criteria presented in ASCE 41-13 are derived based on the mentioned force-deformation relations in this code (a, b and c modeling parameters), what acceptance criteria can be used to evaluate the structure at the IO, LS and CP performance levels if the other force-deformation relations presented in the technical literature (such as Lignos and Hartloper relations for beams and columns of moment frames, respectively) are utilized for concentrated plasticity modeling?

The mentioned curves (Lignos and Hartloper relations) are mostly used in structural modeling to study the structural collapse, in which the collapse is determined by the criteria mentioned in FEMA p-695 and as a result, acceptance criteria in accordance with these behavior curves have not been researched.

i modeled a simple 15cm*15cm concrete block to check the behavior. and applied a compressive load.

problem is input stress-strain is not matching with output stress(S22) - strain(LE22) as in figure.

my doubt is S22, LE22 are correct components to represent or something else is there

Dear colleagues, I am trying to simulate a strip foundation on a cohesionless soil with a friction angle of 30 degrees. However, I obtain convergence problems. I am using a geostatic step.

The error in the simulation states:

Time increment required is less than the minimum specified

Too many attempts made for this increment

I am new modelling soils in Abaqus, therefore, I'm not sure if I'm ignoring some basic concepts or if there is something I missed when inputting the soil parameters.

Thanks in advance

From testing data: yield stress, ultimate stress, total strain, ratio of strain at elastic limit by strain at strain hardening and the ratio of elastic yield modulus to the strain hardening modulus.

**The requirement is basically of finding power law parameters. Or any other model parameter capable of representing plasticity.

I'm trying to simulate a triplet shear test on Abaqus and I've defined both brick units and mortar joints material behavior by means of the Concrete Damaged Plasticity model available in Abaqus' library. I defined the fracture energy in the tensile stiffening data because I was interested in the aspect of softening regularization.

When performing the analyses on two different (homotetique) mesh discretizations, I would expect to obtain the same response in terms of reaction force and imposed displacement, but it isn't so.

Can anybody help me understand why the regularization doesn't work?

Hello,

I have been modelling beam and column using concrete damage plasticity material in Abaqus 2019. After the analysis is done, when I checked in visualization, I got the value of DamageT and DamageC more than 1. the max value is nearly 1.4 or 1.7 above. I have been checked the input parameter and believe that the damage parameter is below than 0.9. Have any one face this problem before? it is a bug or there is any other mistake which I probably have done?

I would greatly appreciate it if anybody could help me with this problem.

I need an explanation from view point of the theories of failure or plasticity theory to explain why the bonding between steel and geopolymer concrete is stronger than with normal concrete.

Hello,

I'm simulating a Representative Volume Element (RVE) to estimate it's homogenised properties under pure compression in X direction.

After some attempts I decided to try just an isotropic material model with one-element simulation, but with the similar boundary conditions, which emulate Periodic Boundary Conditions (PBC) in my loading case: symmetry on X on one side, symmetry on Y on both sides and symmetry on Z on both sides as well. One side is subjected to uniform displacement in X direction. I tested the Extended Drucker-Prager model with perfect plasticity after 120 MPa

What I found out in results is that after yield had begun stresses (mises, pressure, principles and S11) kept on rising up to the end of simulation in the same "straight" manner they had benn rising before yield. It doesn't even seem to look like plastic behaviour.

If I change my boundary conditions to simple support on one side perpendicular to X and retain the displacement on the opposite side, the result picture of stresses begins to look more "plastic-like".

Can anyone explain me the performance of material model in first case (PBC)? Thanks in advance

I'm attaching the plots of the both cases. Units for stress are TerraPascals (i.e. my yield strength is 120e-6TPa), horizontal axis is the applied strain in X direction (recalculated from displacement and X size of the element: strain=displacement/x-size)

Thanks in advance

I know that ANSYS uses J2 flow theory (incremental plasticity approach) to solve the elasto-plastic problem. But I want to compare the results of flow theory of plasticity and deformation plasticity theory. Can I do it using ANSYS or any other commercial software

This is a tribute to the adaptability and plasticity of viruses which facilitates them to make new races.

Hello,

I'm trying to simulate plastic deformation with COMSOL but i don't get any solutions. But if I simulate only linear elstic the simulation converges. What do I have to take into account when I'm using the plasticity module?

Thank you all in advance.

Hello,

I am modeling an impact as a part of my project and due to the large deformations in this phenomenon, I turned the NLGEOM (GEOMETRIC NON-LINEARITY) on, but in a paper, I came across this point:

"Effects of large scale displacements were not included in the study. Soil plasticity at impact was much more significant, and a solution with time-stepping, plasticity, and geometric

non-linearity was not feasible."

Is the mentioned point correct?

I would be so thankful for your help.

I am building a database of fall-cone test penetration depth vs water content. The database has 120 soils approx. Looking for published and unpublished results to increase the number of entries.

I am writing a new plasticity model in Ansys Explicit Dynamics using AUTODYN as solver for Bilinear Isotropic Hardening model but any how unable to add this particular material model code, as I need MATDEF code for above model.

It will be a great help if anyone can help me to write that particular code. So as to define my model and get in continuation with my research.

I want to determine liquid limit and plastic limit for irbid soil, the soil samples are very stiff and have a large size. I want to know if grinding the samples affects of plasticity or not affect.

Thanks in advance

Hello,

As the question suggest, I am curious to know if there are good papers/textbooks on understanding the reloading between yielded and unyielded surfaces.

Say I have a yielded surface due to the elastoplastic contact between two metallic spheres. I unload them and reload them slightly offset from their previous contact positions such that the contact area overlaps previously contacted ( and yielded regions) and virgin non-contacted material.

How would contact during this loading work?

Hi, I would like to use concrete damaged plasticity models for rigid PU foam. i would like to know how to find the parameters for the same

I am trying to simulate the cutting of concrete (without any reinforcement) using a tool with a nose radius of 0.02 mm. I have modeled concrete in 2d using the damaged plasticity model with the values shown in the pictures attached. My tool is a deformable 2d body with an elastic modulus of 200 GPa.

I have modeled the region of concrete that needs to be cut using a mesh size of 0.05 mm. The concrete part is 10 mm in length and 4 mm in height. Tool is 4mm x 4mm. The mesh is set to be linear, explicit and for plane strain conditions with element deletion option set to true.

I have defined cutting speed using the velocity boundary condition and it is 833 mm/s. The stress units are in MPa. Length units in mm. Am also using ALE domain (standard values) for mesh refinement (thinking it might help). Friction coefficient is set to 0.2.

The problem I am having can be seen in the picture named Problem. It is that the concrete is getting pressed in by the tool (feed force) and the region is buckling under compression and eventually leads to excessive distortion error or a zero mass element error.

In my opinion the problem is in the material model itself that it is not getting crushed under compression. Could someone kindly help me out with this? Thanks a lot in advance.

Errors are as follow:

*cap plasticity requires the use of *cap hardening

The material options *cap plasticity, *cast iron plasticity, *clay plasticity, *concrete, *concrete damaged plasticity, *drucker prager, *foam, *crushable foam, *mohr coulomb, *jointed material and *plastic are mutually exclusive

Which diagram for the confined concrete by a steel tube should I use in concrete damaged plasticity model in ABAQUS: uniaxial compressive diagram or confined concrete diagram?

I have made a concrete damage plasticity model of M30 grade concrete. But it is showing higher stress values than specified in concrete property. I am attaching the paper which I took as a reference. Can anyone tell me what may be the reason?

Hi everyone,

I have simple one bay reinforced concerete. I am trying to analysis it with Concrete Damage Plasticity model and I want to get the hysteretic curves to compare with the experimental results. Although I can get good results about max and min capacities of the structure, I can not get the pinching effect and rigidity degredation. Can anyone give me an idea how to get pinching in cyclic loading?

Drucker-Prager Properties used in SAP2000 for concrete only refer to friction angle and dilatation angle while the hysteresis curves also are limited.

Purpose: To calibrate SAP 2000 model with Abaqus model.

P.s: Attached the nonlinear properties of concrete in SAP2000

Hello everyone,

May I know how to model masonry wall using simplified micro modelling in ABAQUS?

Any particular parameters that I should include in my model? (i.e.

*Concrete Damage Plasticity*)I can't seem to find any tutorial on masonry structure online. Would be great if I could get some advice from you. Thank you.

Hello,

According to the power law, Stress=K*strain^n. Could someone please explain why an increase in strain hardening exponent n results in less material necking from this equation?

Please see the attached plot, here I used K=1 to ignore it's effect and I have varied n for n different values.

It seems that for the same stress put into the material, the curve at n=0.1 produces the smallest strain, where as the curve at n=0.5 produces the largest strain, up to strain=1. If the stiffest material is desired, is n=0.1 not more favourable here?

This behaviour changes at strains greater than 1, this has also left me confused.

Any clarification on this will be very much appreciated.

Thank you!