Static Analysis - Science topic

Details of the Analysis.

Static Analysis

Composite Layup

Continuum Shell Elements

FRP Material (Elastic and Hashin Damage)

Hi everyone,

I'm currently working on a static analysis in Abaqus, and I'm facing an issue where I'm not getting any visualization results. I have applied boundary conditions and a pressure load on the surface of the mesh elements using a discrete field. Despite following the proper steps, the results do not show any visualization in the output.

Details:

Steps Taken:

Observations:

Questions:

Any help or insights would be greatly appreciated!

I have a model of a shell plate with several layers of composite materials, designed using CQUAD elements. As part of the static analysis of the model, Nastran provides me with the stress and strain in the middle plane of each layer. Is it possible to obtain the stress and strain in the top and bottom planes of each layer by modifying the .bdf file? I do not wish to use Patran for post-processing.

I have a model of fractured bone which is fixed by particular plate-screw system. I set some frictional contact properties there. Then I tried running the simulation on the model with linear static analysis as my load step of choice. I used Altair Hyperworks with its Optistruct solver.

I can get the result from linear static with simulation time only around 2 hours and the file was only as big as 700 MB. However, when I tried running the same model with the nonlinear static analysis, the simulation kept producing bigger and bigger files, even more than 200 GB. It eventually ate up all my storage, and after that the simulation just stuck there.

I have read some information saying that nonlinear static analysis is recommended whenever we applied friction contact properties. But in my case, can I just use linear static analysis?

I am attempting to create a model of speed core walls (concrete-filled panels) subjected to fire loads in abaqus, using two analyses. The first analysis involves heat transfer to obtain temperatures at the nodes, while the second analysis is a general static analysis where I apply an axial load and then incorporate the temperature. The issue I'm facing is non-convergence due to plate buckling and excessive deformations, especially at the beginning of the process. Any ideas on what I might be doing wrong? I've attached the input file for reference.

Hello everyone,

I encountered a bug in Ansys. I designed one cylindrical shell part. After that, define 3 points and connect them with a line in the design modeler as a beam and define a rectangular cross-section. I put contact between the points and the inner face. Although there is no contact between beams and the surface, It was solved by Anysys. I do not know that it is a bug of the software or analysis setting.

I attached its picture. I would be happy to find a solution.

Hi

im doing a static analysis on lumbar spine , i need to apply a follower load on top surface of my model, can anyone help me with that?

Greetings,

I'm uncertain about how to handle self-weight in time domain analysis of a structure subjected to a dynamic load. I am thinking of three possible approaches:

1) Disregard self-weight entirely.

2) Perform a static analysis considering self-weight as one of the loads, then use the resulting displacements as initial conditions for the dynamic analysis.

3) Treat self-weight as a dynamic load with a constant value, adding it to the dynamic load at each time step during the time history analysis.

I would like to determine the correct approach among these three options. Alternatively, if there's another method, I'd like to know about it.

Thank you.

Hello everyone,

I am currently conducting a stencil printing simulation using ABAQUS. The simulation needs to be performed in 20 different locations on the stencil, requiring a separate simulation for each of these locations. In my case, all components remain fixed, and only the location of the blade changes across these 20 locations. The simulation consists of seven steps. Throughout these 20 simulations, all conditions remain identical from the first step until the fifth step. However, after the fifth step, I change the blade's location in the sixth step and continue the simulation in the seventh step.

Given that the first five steps are the same in all simulations, I would like to explore if there is a way to execute these steps only once and then reuse or restart the results for the remaining 19 simulations. In other words, I aim to find a method that avoids repeating the first five steps in the subsequent simulations. Although I have attempted to utilize the restart option, it did not prove successful due to the blade's location change in the sixth step.

I was performing a cyclic hollow pile to pile cap connection using ABAQUS, I use concrete damage plasticity (CDP) and static general analysis in my model. Some videos on youtube suggesting that since I use CDP which has a softening branch, the static general analysis will not included the CDP parameters I input. You can watch on the link below at minute 10.00 for detailed information. Should I use a static of dynamic analysis?

I modeled two elastic steel plates with cohesive interaction between them and applied a compressive force on the upper plate. I tried to get compressive load-displacement curve but the result is different in Static General and Dynamic Explicit analyses.

In Static analysis the results are not mesh dependent and two plates do not penetrate each other however, in Dynamic Explicit analysis the results are totally mesh dependent and two plates penetrate each other.

I used surface to surface contact for cohesive interaction in Static General analysis and also general contact for cohesive interaction in Dynamic Explicit analysis.

I have results from a load-deflection curve that behaves non-linearly. I need to convert this to a stress-strain curve and/or find the final Modulus of Rupture (MOR).

To do so, converting the deflection into strain is possible as per ASTM D790

εf = 6Dd/L^2, where D is the maximum deflection, d is depth and L is the span length.

I would like to convert the load to stress as well, however, the conventional equation from beam theory is not applicable past the yield point,

σf = 3PL/2bd^2, where P is the load.

I'm aware that it somehow involves the neutral axis and the modified I (moment of inertia) but struggling to make sense of it. The end goal is to find the MOR.

Any help about this is appreciated :)

-The statics analysis is wrong, the experimental design as well as the scientific question cannot been answered by a one-way ANOVA. Also, a couple of control groups are missing.

am working on static analysis on abaqus where friction coeff. is defined to be 0.01 and everything is going on well ....... on replacing the friction coeff. from 0.01 to 0.3 the job is being aborted even by changing the intial and minimum step time to EXTREME values .......

Any one had this problem before ???

I want two obtain Natural Frequency of Cracked blade. I use XFEM crack and do Static Analysis as STEP 1 in ABAQUS whit out any Erro. Now I want to define Frequency Analysis as a Step 2 but when I submitt the job the Software gave me an Error. the Error is Attached.

Who can help me please?

Flexible pavement responses to static loads are different from responses to dynamic loads. While a static analysis has to be performed for the long-term responses of pavement to applied loads, to examine the short-term responses, a dynamic analysis is necessary. Thus, in a dynamic analysis, the dynamic stiffness of material including both elastic stiffness and damping are taken into account. How they affect the fatigue life as compared to static loading of pavement especially when vehicles are moving at different speeds.

I have designed a simple 2D frame in Abaqus using B23 element and after performing a static analysis what I see is that the columns are deflecting but not the beam. I believe it has something to do with the joint. I used MPC Tie constraint to tie beam and column nodes and they have been modeled correctly. Do I need to look at something else for this problem?

Any suggestion/opinion would be appreciated.

Thanks!

I'am trying to do a static analysis for hyperfoam material model. First i started with a simple analysis but i could not achieve a solution. I take hyperfoam coefficents(11) from a paper that you can find at the attached files. I tried to do analysis that is below the "Analysis of the polyurethane sample without a skin layer and without a transition layer" chapter and use constants (11). The analysis that i am trying to do is a simple compression test (fig 4.). Poisson ratios are equal v1=v2=v3 and as a result of this beta terms are b1=b2=b3=0,33.

I think i modeled the test very well by using same elements (c3d8i) in the paper. But I couldn't reach any solution. My model is not able to converge. I am a new user of abaqus so probably I miss something and I am open for your advices.

Figure 9 shows the fea and real test correlation.

You should ignore other chapters at the paper.

My model and the paper are in the attached files.

I want to perform a nonlinear static analysis of the cylindrical shell of revolution subjected to internal pressure formulated using Novolzhilov shell theory and First-order shear deformation theory. I am trying to verify the above problem from paper titled 'Large deformation analysis of functionally graded shells' by Arciniega and Reddy. However, I have solved linear static and dynamic analyses of the cylindrical shell of revolution.

I have used the same formulation and code for verifying a plate-type structure for which I am getting satisfactory results. I am using the standard Newton-Raphson method for linearization.

What can be possible chances where the problem can be resolved?

I am after some benchmarking or evaluating reports, showing that out of a set of static analysis tools one or two are the best in terms of detecting code violations, measuring complexity, etc.

Colleagues, hello!

I set a Field variable in the Material properties to change the Density depending on the Y coordinate. The Material plot shows everything correctly. But after the calculation performed, the results do not differ. For solids and surfaces everything works good, but for beams, the density does not change. Model is loaded with Standard Earth Gravity.

Maybe someone faced such a problem in Ansys 21R2? Thx a lot!

Hello.

I am trying to do a static analysis of a torque box using shell elements and I have the following issue.

I have modeled the Boeing 737 wing (torque box) in Autodesk Inventor using surfaces.

Then I transferred it in Ansys Workbench to start the FEA analysis.

However, I want the inner structure of the wing to be made using composite materials.

So, I opened an ACP module. In that module, I cannot hide some surfaces and here's where the problem is.

If I can't hide them, then I cannot select the ribs and apply an Oriented Selection Set.

I tried, also, making three different ACP modules and then assembling them in static structural (transferring shell data) however that results into an error.

I have attached my project file, without the ACP module.

I am working on a verification of RC shear wall subjected to cyclic loading using ANSYS APDL accurate comparison with experimental paper.

I am applying MCNEMAR test to Compare 2 Machine Learning Algorithms.

Alpha Value Set to 0.01.

If P-Value is greater than Alpha Value,

1st: What is this mean that I am accepting Null Hypothesis?

2nd: Is this mean that my results of both algorithms is wrong?

3rd: What I have to do to overcome this or I can put this test in my documents?

Brief Detail Needed.

Thanks

I have a model of a building in which I have already defined the structural and non structural masses. Structural masses are defined through the density of the material while the non structural masses are defined as point masses. In this step I want to perform the modal analysis. In the subsequent steps I want to define a static analysis and later a dynamic analysis(earthquake). During the static analysis I want to exploit the gravity load for the structural mass while I want to use distributed pressure for the non structural. But if don't remove the point masses I would consider it twice. In the subsequent step I need these masses for the dynamic analysis. To resume, I have to apply the point masses in the first step, remove from the second and put in the third. Is it possible? When I try to do this from one step it's immediately eliminated from all the steps

I am currently solving a static structural problem using ansys. I have given all the inputs but stress is not transmitting across the body. I have attached the files and I am bit new to ansys. Please guide me through the problem.

Assuming we have a piece of timber C16 - 100x100x1000mm and we apply UDL + a point load at middle point on it (parallel to the fibre) as shown below, how much will the timber compress between the force and the concrete surface ?

I have attached a sketch as well. Please see below.

If you could show a detailed calculation would be much appreciated. Thank you!

currently i am working on steel connection using abaqus (quasi static analysis) .i applied the pretension force by thermal load on shank . the problems as followed :

1. is it right to make trial and error till reach ur required pretension force , since the principal calculations didn't give the required temperature .

2. Total energy increased too much during preloading step , and keeped with same high value during loading step , did i miss something .

Thank you

Hey everyone,

I'm modeling a CFS steel shear wall assembly made from back to back columns and a thin steel sheet. I'm using S4R elements and mesh independent fasteners to simulate the screws. General Static step is defined with the Newton Raphson solver. A displacement control loading is applied at the top of the wall to simulate the experiment. My main issue is, I can never get the results of the simulation to match the test results. I'm using a relatively fine mesh (0.5 inch global seed) and the deflected shape and failure modes are in good agreement with experimental results. However, when I compare the force-displacement plots, the model is too stiff and it does not show any material softening at high displacements. The material model used in my model is an elastic-plastic model with isotropic hardening. The stress/strain values were obtained from a coupon test.

After trying many different approaches, a colleague of mine suggested I add geometric imperfections. I performed linear buckling first using a linear perturbation step, I also modified the keyword file to add the displacement variables to the results files using:

*NODE FILE

U

After the buckling analysis, I copied the model in the same directory and performed the displacement controlled static analysis. I included the imperfections by also editing the keyword editor using:

*IMPERFECTION, FILE=Buckle, STEP=1

1,0.8

Where 1 refers to the 1st buckling mode and 0.8 refers to the sheet thickness (scale to the 1.0t of the sheet). The weird part is that the results were exactly the same. I checked the dat file and the imperfections were indeed included in the 2nd analysis however there was 0 effect. I tried using multiple pairs of buckling modes and I got the same results.

I have a feeling I'm doing something wrong, all the literature I checked used a riks step after the linear perturbation step to perform post buckling analysis. What I want is to include geometric imperfections to run a displacement controlled pushover static analysis. Anyone has any experience dealing with such issues? Any comment or suggestion that would shed light would be greatly appreciated.

Hi everybody

I am simulating a static analysis of a prosthetic foot which consists of 10 solids:

- A pyramid adapter

- Three carbon fiber plates

- Two screws that join two plates with the pyramidal adapter

- Two pins that connect two plates to each other

- A polymeric base where everything is assembled

- A heel wedge that serves as a shock absorber

Attached of the ensemble (in Spanish)

The analysis consists of applying a vertical force on the pyramidal adapter of 2240 N, it also has bolt preloads of 10 N and 20 N in the respective screws and pins, and the polymeric base is fixed.

The question would be to choose the types of interactions and constraints in the model.

Hello all,

I am relatively new in area of simulation and I have this basic doubt. I want to know the meaning of time when we are running static simulation. Static means load/BC don't change with time but we give values on time scale.(For abaqus, we define step with total time, initial increment, min/max. incerement) What does it actaully mean? Is it related to - how solver deals with problem and runs the simulation in background?

I am expecting your thoughts/inputs on this topic.

Regards,

Rohit

Hello everyone,

I am trying to do a static structural simulation in Ansys workbench. I have tried applying the bolt pretension condition but the solution does not converge.

Bolt pretension condition:

Part2 with external threads is connected to Part1 with internal threads (tightening torque-25Nm). I have applied the bolt pretension condition to the Part2 outer surface and load 20kN.

Please find the attached image.

Do i need to select the entire Part2 or just the surface in contact with Part1.?

How do i apply the bolt pretension condition..?

Thanks in advance.

Regards,

Vamshi

I would like to carry out a non-linear static analysis but considering my structure's natural modes, and I would like to know how I can set this up in the SAP2000 software

I have tried to consult the user manuals but I have not found anything about the modal pushover analysis.

In the definition of loads for the non-linear static analysis (as show the image below) , there is a section where you are asked to define the modal loads, but I don't really understand what this image is about, and the concept.

I would like you to help me define the modal loads and to understand the concept or basically I would like you to help me perform a pushover modal analysis on SAP2000.

thank you

I am trying to do structural simulation of chassis structure in ABAQUS. Extra solid bodies appears in the simulation results. Chassis is made of hollow pipes and are connected by fillets ( done in solidworks). I observed the geometry, it is hollow inside, and meshing seems fine. But out of nowhere, solid extra bodies appears. Help needed.

I have a dataset of 10 years of a large-scale assessment of Brazil. The data set has students' characteristics and scores for each year. Moreover has several school characteristics.

I'm working at the school level, and I summarised all student characteristics for each school, including scores. The problem was modeled in a binary classification, then my target (average school score) is 1 for school in the upper quartile and 0 otherwise.

Taking advantage of the panel structure at the schools and Brazilian states levels, I am planning to control for the unobservables, that I assumed being present in two ways:

1) Student' ability, motivation, QI... (time-invariant on average in schools and I plan to eliminate)

2) State Policies (I plan to estimate its influence in school gains based on residual effect of each state relative to the reference state - left out dummy)

Then, to eliminate the bias of 1) I took out the school mean within each school for all features, including the target, which was binarized in the end. Now I have a vector of school demeaned features as dependent variables and a binary target which now means: 1 if the variation around the mean is in the upper quartile and 0 otherwise.

Now, I need to infer about 2) in a fixed fashion (for all periods). Therefore I just add a dummy variable for states. So, the time-variant effect relative to the reference state in the period will be estimated, while time-invariant biases will be eliminated.

Finally, I run this final model.

Is it my approach right under assumptions 1) and 2) in addition to those related to the logistic model?

how far am I from causal results?

I want to nonlinear static analysis according to FEMA 440. But in etabs the only option available for the plastic hinge is by using ASCE 41-17 code.

Please let me know how to assign the hinge according to FEMA 440

Static analysis of RC Wall in Abaqus, I have applied 10mm displacement at top nodes. I plotted bottom reaction force in x direction vs lateral displacement of top node. I am getting wavy curve after 30kN load. Why is it like this?

Hi everybody,

does anyone know a good reference for FETI in nonlinear static analysis? There is a lot of literature, but it's usually too advanced and I'd like to find just basic material expalining the rudiments. Apart from the first paper from Farhat et al, which is limited to the linear case, I wasn't able to find much.

Thank you in advance,

JM

hello,

I'm trying to find a well defined protocol to asses spheroid growth during a period. I want to characterize diameter evolution first, then compare with another medium composition .

i'm using the same cell type and 96 wella plates.

i'm planning to :

1- asses spheroid evolution by diameter measurment in defined time points. to ensure that my measurement is relevant , i will probably calculate the mean of N measurement.

which method should i use to estimate my sample size to have a non biased value in this case ?

2- asses wheter the difference in diameter size between each time point is relevant or not.

is T test suitable for this purpose ?

3- asses the effect of medium composition, by repeaing the same measurements.

in this case i'll probably use ANOVA test. Do you agree ?

Thank you

I'm having an issue with running the "new" parametric version of the Kruskal-Wallis. Every time I try to run it using Analyze -> Nonparametric tests -> Independent Samples, I get an obnoxious error message saying "org.xml.sax.SAXParseException: An invalid XML character (Unicode: 0xc) was found in the value of attribute "value" and element is "value". Execution of this command stops."

When I run the Kruskal-Wallis test using the legacy dialogues (K independent samples) it works just fine, but I need the post-hoc results. I have spent literally hours trying to figure out what this error means, but have come up with nothing.

I saw that Warren said "For Kruskal-Wallis, one approach is to run pairwise comparisons (i.e., do a Mann-Whitney for each pair of groups) and adjust the alpha for each using a Bonferroni multiple comparison procedure," but I don't know how to do this. Is there a formula to get the proper alpha to use when doing the Mann-Whitney tests? I tried just running them as is, but I then get several "significant" results between groups that were not significant in the overall Kruskal-Wallis test. I assume this is because of the error multiplication in the Mann-Whitney test, but I may be wrong? Any help anyone can give me would be greatly appreciated!

The image attached is the representation of my application.

This is an assembly of three items (top plate, bottom plate and the 5 load cells).

The bottom plate is fixed and a load of 40 Kg is applied of the top face of the top plate.

The load cells are placed inside the bottom plate and the top plate rests on the top face of the load cells.

I have done the initial analysis in ANSYS workbench.

Need your help to find how much load / force is transferred to each load cells.

Hello,

I am doing a static analysis using ANSYS APDL. I put the load in three load steps. When I try to restart the second load step from the first one, the program give me this error “Unable to write to file Jobname.ldhi. The ANTYPE,,REST command is unsuccessful.” How I can solve this problem. Thanks in advance.

Dear Sir,

I am doing web crippling analysis and it requires more time to converge. I used Dynamic explicit method. Is there any way to reduce the time taken to run instead of changing mesh sizes. Go with the static general may not give accurate results as loads increments are applied using UTM. If there is any way to reduce the run time Please be kind enough to let me know.

Thank you.

question solved and removed, thanks you

I have a doubt regarding a clause of IS 1893:2016 7.7.3 (snap attached ) in which it states that in case of dynamic analysis design base shear from dynamic analysis shall not be less than to the design base shear calculated using equivalent static analysis & if it is greater than in any case than the ratio of both the base shear is calculated and multiplied to the Base reactions and other parameter which is calculated using dynamic method .

Now if we were calculated a ratio from both the base shear and multiplied it the lower one which is a base shear come from dynamic analysis then the base shear is approximately equal to the base shear calculated using Equivalent method

My question is that what is a reason for doing this because we already know that ratio is calculated by numerator divide by the denominator. Code again said to multiply this fraction ratio to value which is in the denominator ( base shear calculated by dynamic method

waiting for a positive response

I am the new users in LS-DYNA. I would like to create the simple cantilever solid beam with static point load at the beam end. How to define the load curve for the static point load? because the static does not depend on time. Do I need the additional step to set up the static analysis in LS-DYNA?

To find equivalent static loading of dynamic events, displacement vector of the dynamic analysis could be used as attached picture.

To use this method in Abaqus, how we could export the displacement vector of Dynamic, Explicit analysis result and import it as equivalent static load in another Static, General analysis?

I have a question about Bilin material in OpenSEES. I am wondering that can we use Bilin material in transient analysis? or this material can only be applied to a static analysis?

Thank you for your help!

I am carrying out a static analysis of an FGM (Functionally Graded Material) in ANSYS APDL. My doubt is where should be the constraints and the loads applied? I mean is it better to apply them on nodes, elements, or areas?

Hi All

I am using Reponse surface optimization module ( and not Direct optimization) to optimize my model ( mono component , shell , large deformation, static load, static structural analysis, around 6 parameters)

what are the weaknesses I should expect from this method, just a DOE analysis took half a day for linear analysis, should I forget about nonlinear static analysis ?

if I optimize a component for its maximum stress or displacement capacity, will it be optimized for all other combinations of movements ?

it's an algorithm implementation model about H. Zou, T. Hastie, and R. Tibshirani. Sparse Principal Component Analysis in matlab.

I don't know how the two parameters work,I'm just setting it up.

Did someone has experience please explain it in detail

thank you!

ps：

Documentation comments

LAMBDA2, STOP

LAMBDA2 specifies the positive ridge (L2) term coefficient. If LAMBDA2

is set to infinity, soft thresholding is used to calculate the

components. This is appropriate when p>>n and results in a

significantly faster algorithm.

STOP is the stopping criterion. If STOP is negative, its absolute

(integer) value corresponds to the desired number of non-zero

variables. If STOP is positive, it corresponds to an upper bound on

the L1-norm of the BETA coefficients. STOP = 0 results in a regular

PCA. Supply either a single STOP value, or a vector of K STOP values,

one for each component.

and model file

Hi experts,

I am developing a pushover analysis of a structure with SAP2000.

It is a reinforced concrete structure that I want to compare with the same structure, but adding a shearwall.

The model without shearwall (bare.sdb) shows an adequate capacity curve as can be seen in the bare_curve.png.

When the shearwall is added (model: 18FN.sdb) to the same model, the demand curve, as well as the capacity curve show errors, as can be seen in infill_curve.png. I imagine that it may be because there are too many null steps and therefore you cannot draw the curve correctly, it also shows the nonlinear static analysis as "unfinished" and all other load cases as "finished".

Can anyone please help?

if I'm planning to check accuracy of multiple bacterial identification kits what is the statical analysis that can give me better and accurate results should I choose

I want a tool to make assertion count and also static code coverage. I've seen call graph analysis based technique from Alves and Visser's paper but if there is any other, your recommendation is appreciated.

FEA Software for mechanical structure analysis

I tried to use LDREAD command to take results from a static analysis into the harmonic analysis, but it fails to read the file. I've been using it as LDREAD,REAC,LAST,,,,'structural','rst',' '. Are there other way to take results from different analysis into another?

Hi. I want to model a structure and write some codes to difine static analysis in my thesis. I will be so hopeful if someone is being able to help me.

To calculate the value of Response Modification factor "R" of any structure, a nonlinear static analysis can be done and for that linear static design is usually carried out. During that stage, a vale of R (based on the standard followed) is given to calculate the base shear for design. Doesn't that predefined value affect the final result?

I am looking to start working with the isogeometric method to analyze mechanical behavior such as beam, plate, shell and other structures of complex shapes.

can you help me by giving me simple examples in this method and with articles and books that have explanations and applications?

what do you suggest to me and thank you in advance?

I am using axisymmetric stress explicit element but results are showing an error stating excessive distortion. Although I have performed similar simulations with static analysis which worked fine.

Hello everyone. I have been working on bistable states of a hemispherical shell cut at a height( like cutting a tennis ball at particular height). I have been able to do static analysis of hyper elastic( neo-hookian) material. But while doing explicit dynamic analysis, the elements distort excessively. Can anyone please provide some guidance?

Basic Information:

Static-General Analysis

Time Period: 1s

Number of Increments: 1000

Initial and Max Increament Size: 0.02

Minimum Increment Size: 1E-008

i want to make a dynamic analysis in ansys apdl is there a way i can transfer loads (previosly used in static analysis) i have into masses? so i can perform a dynamic analysis.

Hello all, I need a help really. I have displacement at a point as in the image where it shows Mag = 0 and Z = 0. Apart from static min and max. That nodal point on top I needed the values. Since everything shows up zero. I don't know what went wrong. Since I can guess the static min and static max from the left contour plot. But I really need the nodal displacement which is set but everything shows zero due to an error. Software - Hypermesh. Please do help me

I ran an abaqus model of nonlinear static analysis and there is no error message. The message file actually said the analysis completed in 54 increments. However when I loaded odb to abaqus for visualization, there are no increments to show for the step. Any reason why?

Hi everyone,

I am performing a static analysis in ANSYS APDL