Science topic
Structural Analysis - Science topic
Structural analysis is the determination of the effects of loads on physical structures and their components. Structures subject to this type of analysis include all that must withstand loads, such as buildings, bridges, vehicles, machinery, furniture, attire, soil strata, prostheses and biological tissue.
Questions related to Structural Analysis
In his name is the judge
Hi
for using matlab facilities especially matlab controller like fuzzy have to sending and receiving data between matlab and opensees, in fact i want send two data as fuzzy controller form opensees to matlab after each time history step in opensees and then matlab send back one output to opensees.
to achieve this i have to connect matlab and opensees with openfresco it means i do hybrid simulation.
first is this possible to do this?
second is there any one do work like this, do hybrid simulation generally or specifically do hybrid simulation between matlab and opensees. if yes i am very thankful to share work with me or for some aim.
have to say i prefer not to use openseespy and i almost read all example and guide in openfresco site and even on each site but i cant do this right.
Any help is greatly appreciated.
Take refuge in the right.
The psychological, inner mental activity, is a process. Usually it is hard approaching dynamic phenomenons by means of structural analysis, where intuitively things are seen in some static way. On the other hand, psychological activity is a very complex issue, and complexity can be frequently managed by systemic structural methods.
I am currently testing a basic design for my research topic with a hollow cylinder.
The displacement was set as 0 on one end as a fix support and -5 in Y direction on another end.
The reaction solution i had is different from in Ansys Mechanical and i believe that the result generated from APDL was wrong.
The last screenshot is the result from APDL using .cbd file from Workbench mechanical
The result is still incorrect comparing to the result from Workbench Mechanical.
What is my mistakes here or any suggestion ?
To whom it may concern...
Case shown in pictures below need to stop in front of it...
Starting with the way of supporting slab before casting.. the question appear...
Based on your engineering opinion, and supporting method that you might used... is what shown in pictures attached ,.. enough.. ?
Then... whom responsibility is that... if slab fail during casting process, as there will be additional loading of pumped concrete and labors also ...? where that will be the most important question....
To whom it may concern...
Case shown in pictures below need to stop in front of it...
What the mean of overload... What will be the meaning of calculated loading before design... and.... What really mean the structural design based on submitted data..
All, in general,.. knows that.. design start with converting functional use of the building to loading on structural element... then start design element by element ...
So, what might be the supposed loading to one story house... based on all adopted code... ? this is the first question..
Then what you think, .. or what the supervisor engineer might think the value of such loading on that slab shown in pictures attached... ? this is the second question...
Then at last... whom responsibility is that... if failure occur...? where that will be the most important question....
Limited education with low experiences causes such cases, ... or... we need to ask the supervised engineer if he care...
In his name is the judge
Hi
I want design cotroller in to control active force of damper.
On this purpose, i analyzed structure with damper, wich is tlcdg, and get data whic use for generate controller. data are accleration and velocity of damper as input and dampers force as output ( i mean force wich made by own damper under earthquake excitation, not active force).
here is anfis properties :
number of inputs are 2
number of outputs is 1
generate fis method is grid partition
number of membership function are 4 for each input
input membership function type is guass2mf
output membership function type is linear
opt method is "hybrid".
(have to say i tried different epochs membership function , .....)
Unfortunately anfis toolbox in matlab refuse to train and build Suitable fuzzy controller wich means error is too much in training, so this answer is not acceptable.
i have some idea for make it true but i'm not sure.
here is my ideas :
* first i think train controller with more or less data ( training data are about 2000 wich is under 100s earthquake excitation but when i reduce earthquake excitation to 10 or 15 seconds the error is acceptable however i think this solution is not good.)
* second maybe i must try one damper for training.
* the last idea is to assign force on the damper location and get acceleration and velacity for generate trianing data.
here is my data and shot frome my try.
Any help is greatly appreciated.
Take refuge in the right.
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.
Dear all,
I would like to do a welding heat transfer analysis in 2D and map these results to a 3D model for conducting structural analysis. Is there any way to do the same?
Can any one suggest references for the same?
There is nothing worse for curb appearance than chipped and cracked concrete, particularly in steps. But you don’t have to put up with that blight any longer. By the result of weather changes exerted on an existing construction for prolonged time, it causes contraction and expansion those gradually results concrete steps cracks and break up with time.
Dear researchers, I would like to get expert opinions on how to fix this issue with,
optimum efficiency
low cost
prolonged sustainability .
Your answers are highly welcomed.
I am doing a 2D pure shear isochoric strain analysis with 20% pure shear in ansys workbench using ansys static structural in ansys workbench. Previously in ansys mechanical apdl, there is a scope to enter displacement as a function of coordinates of nodes. The equations of my constituting boundary condition are
U = 0.2 *X and V = (-20/120)* Y. Here X and Y are the coordinates of the concerned node. How do I use them in ansys static structural analysis? Please guide.
Hello,
I am studying the performance of 2 wing models (with the same size, constraints, loading and material properties but different material distribution) using Nastran. Wing A is lighter and 24% stiffer than wing B and that is demonstrated in the static analysis (under a distributed load on the top skin).
The two wings have about the same fundamental frequency (34.25Hz and 34Hz). Using the relationship f=sqrt(K/m), the difference between the two frequencies should be significant.
Also, the divergence analysis yields exactly the same displacement for the two wings.
Does any one know what could be causing such results? why the divergence displacement is not smaller for wing A (since it is stiffer) and its frequency is not much higher than wing B?
Thank you in advance for your input.
Dear researchers.
I am studying one way FSI using fluent and transient structural, my problem is that when I transfer the result directly from the fluent, I can not observe the correct deflection as the response should be a stepped as the excitation is a step function.
The relative total pressure on the structure surface is correct and I verified the plot.
I think that in transient I could not read the time steps even that I followed the correct step.
one of the solution I crossed with during web searching is to use external data transfer.
I know how to export pressure time value yet how to make the solver know that the pressure zone is as described in the attached picture?
In recent years, there has been development of some innovative construction technologies that are changing the way we build. There are many new technologies that will have a significant impact on the future of the construction industry.
Today, construction companies are able to complete projects more quickly and efficiently than ever before. There are new technologies in demand for the future that will help with accuracy, sustainability and faster construction.
Based on your point of view, what are the types of construction that can be used in future?
I will really appreciate if anyone could give some tips on the use of Lusas and SAP 2000 software for modeling and structural analysis. Thanks
Can anyone suggest to me method to design fuzzy inference system (FIS) for MIMO structural damage detection (i.e. data distribution on the membership function, parameters of MF, Generate rules ... etc )
In my system there are 3 inputs and 2 outputs:
Inputs: Relative 1st Natural frequency , Relative 2nd Natural frequency , Relative 3rd Natural frequency
Outputs: Crack depth ratio , Crack Length
Note: I tried to use "genfis" By MATLAB it didn't give me reasonable results.
Data science is a growing field of technology in present context. There have been notable applications of data science in electronic engineering, nanotechnology, mechanical engineering and artificial intelligence. What kind of future scopes available for data science at civil engineering aspects in the field of structural analysis, structural design, geotechnical engineering, hydrological engineering, environmental engineering and sustainable engineering?
Complex graphical sketches are highly involved in Culmann's methods. Therefore, it is highly prone for getting deviations in magnitudes for resultant pressure on retaining wall. I would like to get suggestions from RG colleagues on why Culmann's graphical approach is mostly preferred in many research papers albeit Rankine's method is easy and precise in terms of equations and substitutions. I would welcome answers from both theoretical and practical perspectives.
Hello Researchers,
The FEM discretized (meshed) geometry/domain is considered stiffer than the actual geometry/domain due to the assumption of variation of the displacement within each element. This is analogous to the displacement being constrained to vary in a particular fashion within each of the elements. This results in the stiffness of the discretized domain being greater than the actual domain. As the element size decreases (or the number of elements increases), the constraint on the displacement loosens due to the smaller size of the element and hence, the smaller constraint zone. Thus, the stiffness of the meshed domain decreases and approaches that of the actual domain as the number of elements is increased.
Based on the above reasoning, the natural frequencies (on increasing the number of elements) must converge from above to the actual value (i.e. converge from higher values to the actual value).
- Can this be considered to be strictly true?
- Has any deviation from it been observed (i.e. convergence from below or lower values to the actual value) and if so how can that trend be physically explained/interpreted?
I am looking for stress-strain data for steel to input for the plastic properties in Abaqus. However I cannot find any literature or experimental data on the matter. If full data is not available then the strain or deformation rate will also be helpful. Should I assume a 2% strain rate in the absence of other data?
How can I get the equivalent(effective) Young modulus and Poisson ratio of a multilayer structure? A structure like the below picture. the structure is consists of Si, Al2O3, and Al metal thin films. They must be simplified into one equivalent layer.
Thanks.
So If a column isn't casted exactly in the intended location according to the structural drawings, and the centre of this column is moved 3 cm away from it's original location.now in the ACI code, accidental eccentricity is taken into account in the column design equation,so the question is how to check If that eccentricity is within the allowable range? According to the ACI?
While doing profile matching in full prof chi-square value is stuck at 12. When I try to refine u,v,w parameters their value reaches up to 38. What might be the possible reasons for the non-refinement of these parameters?
Structural analysis and morphological analysis
in his name is the judge
hi
I wrot a sub code on opensees for active tlcd or tuned liqiud gass damper (tlcgd) and assign it to some structures, it seems worked correctly.
In next step i want to optimize tlcgds location on each story with some objects like max dislacement or torsion ratio and ... so i have to use multi objective optimization (which may NSGAII algorithm is the best choice) code or toolbox on matlab and simulink. For this purpose i want to run NSGAII algorithm in matlab, then algorithm Calling my code in opensees (tcl) and run it, after that NSGAII algorithm modify damper location (in opensees code) after each timehistory analysis In order to improve objectives and then analysis my code again and again until find best location for dampers.
Note that I actually want to changing dampers location be part of the NSGAII algorithm and the algorithm itself automatically relocation the dampers to get the best answer.
one best solution may use openseespy but i think it's not free access and i can't get it from iran, So i think realyhead Over heels in this case.
Any help is greatly appreciated.
Take refuge in the right.
What can cause severe bending conditions on the wind power plant's tower(only the tower part)? I assume that as the wind hits the blades it create a bending moment which vary linearly from wing tip to wing base. This moment will be transferred from blade's base to the top of the tower ( we have then a model like a beam with one end fixed and a bending moment on top). And I think that this moment has larger condtribution to tower's bending than the force coming from the wind as it hits the structure. Correct If I am wrong.
Hi,
Can any one please let me know how to configure ABAQUS solver for ANSYS workbench? So I can run simulations using ABAQUS solver which are pre-processed in ANSYS.
I read the help file, but I'm bit unclear what to do!
Thanks in Advnace!
Hello friends
Nowadays I am trying to use Code_Aster to simulate CABLE . I want to know how to add a force like this F=0.5*velocity^2 on selected nodes?
And how can people add a triangle distributed force on a moving cable whose coordinate is changing with time .
Thanks for your help in advance.
Is the only way to differentiate between short and long coloums according to ACI is through slendeness ratio? Is there an easier approach?
Structure Erection and Civil Works
1)Brief on civil foundation and, erection of supporting structures.
2) Fixing the foundation of the structure and, the grounding considerations.
3) Installation of mechanical structure
4) Foundation: Reinforcement and Shutting other balance of systems
5) Mechanical safety aspects.
What should be done if items did not load in EFA?
should they be discarded? Or that means that they are unique and do not have partners?
What if these items are important or represent our dependent variables ? Can we include them as single items?
What are the programs which can be used for structural modeling?
I have used an AMOS previously but the trial period had run off, so are there any other available programs for the use which are free of charge?
thanks
Hello everyone,
My dependent and independent variables are loading on the same component when performing EFA, Also CFA does not show a good fit when they are combined in one model but separated into different components.
I think this is due to the high correlation between them. So should I separate the questionnaire into different scales and perform EFA/CFA for each scale independently. Then combine them together in a path analysis later?
How can I validate a questionnaire for a small sample of hospitals' senior executive managers?
Hello everyone
-I performed a systematic review for the strategic KPIs that are most used and important worldwide.
-Then, I developed a questionnaire in which I asked the senior managers at 15 hospitals to rate these items based on their importance and their performance at that hospital on a scale of 0-10 (Quantitative data).
-The sample size is 30 because the population is small (however, it is an important one to my research).
-How can I perform construct validation for the items which are 46 items, especially that EFA and CFA will not be suitable for such a small sample.
-These 45 items can be classified into 6 components based on literature (such as the financial, the managerial, the customer, etc..)
-Bootstrapping in validation was not recommended.
-I found a good article with a close idea but they only performed face and content validity:
Ravaghi H, Heidarpour P, Mohseni M, Rafiei S. Senior managers’ viewpoints toward challenges of implementing clinical governance: a national study in Iran. International Journal of Health Policy and Management 2013; 1: 295–299.
-Do you recommend using EFA for each component separately which will contain around 5- 9 items to consider each as a separate scale and to define its sub-components (i tried this option and it gave good results and sample adequacy), but am not sure if this is acceptable to do. If you can think of other options I will be thankful if you can enlighten me.
How can i validate a questionnaire for hospitals' senior managers?
Hello everyone
-I performed a systematic review for the strategic KPIs that are most used and important worldwide.
-Then, I developed a questionnaire in which I asked the senior managers at 15 hospitals to rate these items based on their importance and their performance at that hospital on a scale of 0-10 (Quantitative data).
-The sample size is 30 because the population is small (however, it is an important one to my research).
-How can I perform construct validation for the items which are 46 items, especially that EFA and CFA will not be suitable for such a small sample.
-These 45 items can be classified into 6 components based on literature (such as the financial, the managerial, the customer, etc..)
-Bootstrapping in validation was not recommended.
-I found a good article with a close idea but they only performed face and content validity:
Ravaghi H, Heidarpour P, Mohseni M, Rafiei S. Senior managers’ viewpoints toward challenges of implementing clinical governance: a national study in Iran. International Journal of Health Policy and Management 2013; 1: 295–299.
-Do you recommend using EFA for each component separately which will contain around 5- 9 items to consider each as a separate scale and to define its sub-components (i tried this option and it gave good results and sample adequacy), but am not sure if this is acceptable to do. If you can think of other options I will be thankful if you can enlighten me.
Hi
I had a questiones about the operation of the Riley damping command in Opensees.
First, how does the Rayleigh Damping Command affect the damping in any structural mode?
Second, can the Rayleigh Damping Command be set to affect only certain modes of the structure?
Any help is greatly appreciated
I wish you all the best
I am doing Response spectrum and Linear time history analysis in RC building for my project. I have to consider infill consideration in the building, So i have calculated Strut width as per FEMA 356, using masonry property of Indian Standard. I have modeled strut assuming pinned jointed frame element having material properties as per masonry property as per Indian Standard. BUT i am unable making it not to take Tension in strut when running the analysis. And i am not able to make it not to take Dead and live load response,as infill should not take any dead and live load from the structure. So , how should i model strut so that it will be tension free and it takes only compression? how can I model it in ETABS so that it will not take any live and dead load from the structure? and i am not quit clear about that should strut is modeled for Nonlinear analysis( Pushover, nonlinear time history) only OR can it be modeled for Linear dynamic such (RESPONSE SPECTRUM, LINEAR TIME HISTORY ) analysis??? and how can i model it in Linear dynamic analysis??
Thank you!!!
Hello everyone, I am designing a 7-story steel building using STAAD Pro software. I made it and when I saw it in render view, it showed intermixed I sections at column beam joints. What type of joint is that?
I am going to count the number of votes. So please select only: Concrete
or
Steel.
Just one word is enough.
Overall Sciences ... Overall Designs... Do we need always to consider Factor of Safety ... ?
Hello,
Could you please recommend me a good reference on the generalized theory of beams? In particular, I need one that includes the warping effects due to bending (7th DOF).
The only one I know is "Walter D. Pilkey (2002) - Analysis and Design of Elastic Beams: Computational Methods".
Kind regards,
Diego
I'm trying to create a python script to get the "real" resistance of columns through Finite Element Analysis, and I wonder if there is any possible way to extract the eigenvalue in "Buckle" analysis automatically and then use it in Riks analysis (non-linear) without the need to do it manually.
In Abaqus command line interface, i usually use this script to manually extract the eigenvalue e.g. 1st:
>>> import odbAccess
>>> a1=odbAccess.openOdb('Buckle.odb')
>>> a1.steps['Step-1'].frames[1].mode
1
>>> a1.steps['Step-1'].frames[1].description
'Mode 1: EigenValue = 5.02675E+05'
But how can i automatize it in Python script and automatically insert the chosen eigenvalue in Riks script as the new load applied, see screenshot below:
Also added buckle script
and Riks script (-NL)
Hello,
I am trying to preprocess DWI data for the first time in order to extract diffusion parameters and to perform tractography. I have watched all the tutorials provided by the Analysis Group (FSL), Andrew Jahn videos on Youtube and I have studied the DTI pipeline. However, I still have questions.
It is not very clear if I should preprocess my T1 data too. I am using it to perform registration with my diffusion images. I know that I should extract the brain (Bet function) but I was questioning about possible others steps I am missing? I am afraid it could bring artefacts onto my results.
Thank you for reading me,
In your opinion which is the best software to analyse a 3D frame:
(a) STAAD
(b) ETABS
(c) ABAQUS
What are the merits of your answer?
Hi there,
For defining damage variables in Abaqus, what stress-strain curve would be appropriate to use to define these two concrete damage variables?
Because some of the empirical concrete stress-strain curve give value of damage variables up to 0.7-0.8; I am looking to get at least damage variables of 0.9 (for dt & dc) when calculating these variables from the post-peak response of concrete curve.
Cheers,
Dear
I am performing a series of structural analysis test through software, for some model I already have the experimental results so the selection of mesh is related to this results, the good mesh is the one who gives the best approximation to the desired results but....
In Case we are testing a new design or a new structure without any previous knowledge , how to know the correct mesh?
Please compare various common programs, e.g., ETABS, TEKLA, etc. as well as the new generation of parametric ones, e.g., Karamba, Kangaroo, etc.
Please reply by referring to valid scientific papers.
I'm trying to create a python script to get the "real" resistance of columns, and I wonder if there is any possible way to extract the eigenvalue in "Buckle" analysis automatically and then use it in Riks analysis (non-linear) without the need to do it manually.
Basically, extract the eigenvalue from Linear Petrubation - Buckle analysis, and use it in another model with Riks analysis to get LPF and automatically and plot Force-Displacement plots.
I performed transient structural analysis on a shaft geometry as a result I got the amount of thermal deformations. shaft geometry has different diameters on the surface, how to calculate the increased diameter or thickness for different areas of shaft i.e. after deformation.(without using code)
@
Claudio Pedrazzi
Is there any analytical formula that relates the longitudinal deformations to the transverse deformations of a cantilevered beam subjected to a transverse applied load?
I am trying to simulate buckling phenomenon of ion source grids under thermal load in vacuum.Two grids namely screen grid and acceleration grid made of SS304 are mounted on a SS flange.The grids are electrically isolated from each other and SS flange by ceramic bushes.The inter grid spacing is maintained by brass spacers.I want to fix the grids at the bolting location so that it does not have any deflection there.A heat load of 300W is applied on the face of screen grid which faces the flange.There are no apertures in the model as it is just a preliminary study.The thickness of each grid is 1mm.
Following are my questions.
- What kind of contact(bonded,rough,frictional etc) should i define between brass spacer and grid and brass spacer and ceramic bushes to get proper deflection results?
- On what faces of the assembly should I define radiative boundary conditions? (Just 2 grids or even bolts,nuts, flange etc)
- Which area of the assembly should contained the fine mesh size? Since I am using a regular 8GB desktop I am not able to make meshes <2mm element size.What is the criteria for choosing mesh size?
- How can I know that the output by ansys is correct? (i.e the direction in which the grid buckles is right or wrong?).
I have attached picture of a sample run output for understanding.I have labelled all the components in the geometry.Please feel free to ask if you need any other details.
Thank you
I mean the mathematical component of said process.
I mean the use of the SQUG database to assess the seismic resistance of NPP equipment with the specified type of reactor.
I simulated a cylinder of length 75 and radius 2 in Abaqus using shell elements (S4R) for the cylindrical shell and solid elements (C3D10) for flanges. The connection between flanges and cylinder is done via shell-to-solid constraint. The thickness of the cylinder is varying from 0.03 at bottom to 0.013 at top. At top a concentrated lateral force of 100 is applied. Bottom edge is fixed.
I wanted to validate my results by comparing it with a beam. Thus, a beam is created of length 75. The thickness again is varying from 0.03 to 0.013. Same BC and load condtions are applied here. No influence of flanges here, just a straight beam divided into parts with different thickness. B31 elements are used.
A linear static analysis is followed. While displacements are close, I noticed something stange regarding Von Mises stresses. The location of S.Mises at both models is different. In cylindrical shell max Mises is at boundary while in beam model is above boundary. Any idea why is this happening? I was expecting also S.Mises for beam to be at boundary
Dear all,
I want to connect two parts in abaqus. One is a cylindrical shell and the other is a solid deformable ring. The ring will act as a stiffener for the cylindrical shell. My question is what is the appropriate way to connect them?
1) Should I connect the parts in Assembly modulus and then merge them together?
2) Should I design both in Part modulus?
3)Or should I tie them with a solid-to-shell constraint?
What is the best strategy? How the results will be affected by choosing one of these 3 methods?
I am studying the book "Structural Analysis with Applications to Aerospace Structures" by Craig. In Chapter 8 titled "Thin-Walled Beams", the authors derived the governing differential equation
dn / dx + df / ds = 0
where, n is the axial flow, f is shear flow, x is axial coordinate, and s is curvilinear coordinate along cross-section. Here we can substitute n = sigma * t where sigma is obtained from Euler-Bernoulli beam theory. Using this approach, we can determine shear flows and then shear stresses in each section of cross-section.
Another way to determine shear stress in a beam cross-section is to use Timoshenko beam theory.
Question: What are the difference between the shear stresses obtained from the two methods? Do both approach capture the same effect?
Dear all,
I want to use ring stiffeners in order to increase bending resistance of a cylinder. The rings has outer diameter R1 = 2 and inner diammeter R2 = 1.85. Their thickness is 0.12 . They will be attached in the inner of the cylinder.For modelling them in abaqus, solids or shells should be used and why?
Dear Scientists,
I have a question, we want to use the application of ANNs in regression analysis and this is some sort of easy utilization for ANNs, but the question is " how many samples do we need to training? using 12 samples could be enough? " I produced these 12 samples by Fractional Factorial Design (FFD) method and I need to be sure about this. Therefore, I would be grateful if you could provide me with any information about this subject.
Many thanks in advance for your time and kind consideration.
Regards
Mohsen
Reference for FFD method: https://en.wikipedia.org/wiki/Fractional_factorial_design
HI,
can anyone explain me how to get modal mass coefficient and modal participation factor as per ATC 40 from SAP 2000?
I am doing structural analysis of epoxy composite with natural filler. Facing problem in material selection. Because not available in engineering materia library of Ansys.
I recently started using the Ansys workbench for my thesis project, and I would like to ask the best approach to show the post-processing results? For example, I had run a transient structural analysis simulation, and I got a result, i.e., deformed body, how we will compare the deformed body to the original geometry to find change in volume or diameter, etc.?
or is there any better way to show my results for people to understand in easier way
Is it right to face socioeconomic status as a latent variable? May you give an example?
Dear all ,
I have a one fixed-end cylinder under bending force simulated in Abaqus. I run a geometric non-linear analysis and now I want to find the curvature at some specific point across the length. I want to measure the curvature ( κ ) at a portion of my model ( dz ) by applying κ = dθ/dz = (θc1-θc2 )/dz ,where θ is the rotation around y-axis and θc1,θc2 is the rotation of the center of the portion dz. Is it possible to find these rotations at the center c1,c2 of a portion of my model? Is any other way to find the curvature?
I am studying the behaviour of cylindrical shells under bending loads. I simulated in Abaqus a straight cylinder of length = 100 , radius = 2 and thickness =0.05 . S4R elements are used. The cylinder has one end fixed and the other is free. (Rigid body kinematic conditions are applied in a reference point in middle of cross section at both ends). A displacement load is applied at free end and a geometric non-linear analysis is followed.
The model under bending load is subjected to ovalization of its cross section. My question is how can I measure this ovalization and how can I find the moment distribution across the cylinder in order to find at which moment the collapse occurs?
I simulated the same problem using both wire beam and shell elements. The model is a cylinder of length = 100 , thickness = 0.05 and radius = 2. One end is fixed and the other is free. A displacement load in x-direction of 27 is applied on free edge. For shell element S4R elements are used and for the beam element quadratic beam elements. My goal is to check if these two formulations give the same results. However , I created free body cut ( at half of the length) to check if moment and reaction forces are the same. There is a difference between 2 models. Why shell formulation is not close to the beam one?
in structural analysis, I would like to know what is the real physical meaning of having a low and high natural frequencies?
which is better to avoid structure with low or high natural frequencies?!!
Good day Sir/Ma'am, anyone here knows how to extract data from structural analysis software specifically from ETABS to MS Excel. Thank you and God bless!
I've done the Modal Analysis followed by Structural analysis in Ansys Mechanical & now I want to export my model in State Space Form. So that i can use it in Matlab.
Everything works well except loading of input vectors, I've followed guidelines from the link below:
example:
my query is that the given link provides accessibility to define DOFs in ux, uy & uz. However, I want to Include variable forces in x,y & z direction that will be controlled by my Control Algorithim in Matlab. how can I add forces as input?
The link also says if i don't define any input array it will define all the Loading vectors in the system as Inputs(by Default). But it's not working as it says.
Note: I've defined "Nodal forces" using "Named Selection"
Hi everyone.
I'm currently working on replicating the load-displacement backbone curve result from an experiment of a simple circular column subjected to slow-cyclic loading. The specimen is subjected to a constant axial load of 890 KN and a lateral load with a 978 KN servo-controlled hydraulic actuator. The column has couplers placed near the support.
I modeled the column with couplers using SAP2000 with auto hinge property ( P-M-M). The axial load is assigned as nonlinear static ( zero initial conditions ) while a displacement controlled static nonlinear load case for the lateral load ( continue from state at end of NL case "axial" ). My column eventually failed at step 27 of the displacement-controlled load case.
The results between the 2 are quite the same for the yielding load and displacement, however, drastic changes can be seen in terms of ultimate load and strain. Kindly see photos attached for comparison.
What seems to be the problem? Any suggestions Re: use user-defined hinge properties generated from other software.
Thanks!
I am interested to perform spectral analysis of a structure under random waves. could anyone suggest me a book or an example that starts from wave spectrum (such as
JONSWAP spectrum , P-M etc) to RAO. A complete example from formulation to numerical evaluation.