Hi all please check the following link: as you can see it's a pipe system modeled with shell181 elements subject to internal pressure (only) i need help about the membrane stress i get at the nozzle intersection - it should be considered local membrane stress so the allowable stress limit should be 1.5S, is it correct? - or maybe, since it's a very high geometry discontinuity location, i can consider the allowable stress limit equal to 3S? I have been increasing the main pipe and the nozzle equivalent tickness to low down the membrane stress but the solution i'm getting out is not cheap and hard to build any nice tip would be very appreciated thanks RE: Ansys Asme Pipe Stress Analysis - fast question (Structural). Jos007 - unfortunately, evaluating the results If a finite element analysis to the piping or BPV Code is slightly more nuanced than your questions imply.

It appears that you are trying to perform an evaluation in accordance with ASME Section VIII, Division 2, Part 5, correct? Probably you have arrived there by apply the 'unlisted component' rules if ASME B31.3?

What other loads are there on the component? You will need to evaluate those, too. Be glad to help you but I would need to know the whole picture. Are you expecting any cyclic loading?

How about vacuum conditions or anything else that might result in compressive loads? RE: Ansys Asme Pipe Stress Analysis - fast question (Structural).

Overview In this tutorial you will examine the expansion of a pressure vessel due to an internal pressure using ANSYS. The problem is adapted from case study E on.

You are mixing two different failure modes. If you are actually following the rules of ASME Section VIII, Division 2, Part 5 (2013 Edition), then you will know that for satisfying Protection Against Plastic Collapse, the local membrane equivalent stress should be less than Spl (which is the greater of 1.5S or Sy). If that is not met, then your have not satisfied this failure mode.

For satisfying Protection Against Failure From Cyclic Loading: Ratcheting, then the RANGE of primary-plus-secondary membrane-plus-bending should be less than Sps (which is the greater of 3S or 2Sy). Whether or not this is met, you still need to satisfy the other failure modes. Download Smog Discography Rare. And, for that configuration, you would still need to satisfy Protection Against Collapse From Buckling and Protection Against Local Failure. On the last one - Protection Against Local Failure, your geometry is one that is susceptible to such a failure mode. And a shell model is insufficient for making such a determination (the issue is in the inside corner of the lateral). Interbase Xe Server Keygenguru. RE: Ansys Asme Pipe Stress Analysis - fast question (Structural).

Evening All, here: you can find my stress analysis of the solid model regarding the failure check against internal presure (only) according to ASME VIII div2 2013 My biggest doubt is about the stress categorization, i'm not sure to consider the nature of the bending stress @ the nozzle intersection correctly: as you can see in the 'report', i assume the primary bending stress Pb = 0 (always) @ nozzle intersections, because it's a strong local discontinuity region so, to check the stability of the item, i execute the following checks: considering A516 Gr65 @20°C (Sy/Su. A couple of comments: A) You need to ensure that you are performing the Protection Against Plastic Collapse checks using the Design Pressure, and not the hydrostatic test pressure.

B) Your assessment that, at the intersection, there is no Pb is appropriate. C) When performing the ratcheting check, you should be using the operating load ranges. See D) When performing the Protection Against Plastic Collapse and the Local Failure check (4S), you need to be using the load case combinations described in Table 5.3 E) You are using ANSYS. Please note that the linearization scheme in ANSYS is NOT compliant with the requirements of 5-A.4.1.2 Step 2 (a).

F) Your Figures make it next-to-impossible to see if the SCLs are appropriate. Please refer to Annex 5-A for SCL guidance. G) The Local Failure check is for primary membrane-plus-bending principal stresses only. It does not include secondary stresses nor peak. RE: Ansys Asme Pipe Stress Analysis - fast question (Structural). HI TGS4 thx a lot for the answers about the comments: A) I did that too, but with the Design Pressure i get accettable values, with the test pressure i have not.

I can't find load combinations with the test pressure for an elastic analysis. Does that mean i have to switch to an Elastic-Plastic Analysis or a Limit-Load Analysis to check the item against the Test Pressure? Is it mandatory? Do you think it's right to assume Pb = 0 along the longitudinal side too? Please check the following image to see what i mean: since it's close to a geometry discontinuity it should be correct C) ok, i will check it carefully D) ok E) ok, i read about it F) I have re-uploaded the file, now it should be easier to check the chosen SCLs: G) ok, btw if i do the check considering the secondary stresses too it shoud be conservative, do you agree? H) i have a little question: considering a material having the ratio Sy/Su we have Spl = Sy according to 5.2.2.4 step 5. The Sy value of the material at the ambient temerature is easy to get, but at the design temperature, where do i get the Sy(T)?

I mean the Yield Limit at the Design Temperature On ASME Section II, Part D, Table 5A i can only find the S(T) value, but assuming Spl = 1.5*S(T) should be wrong according to above. What should i consider? Thanks a lot for your time! RE: Ansys Asme Pipe Stress Analysis - fast question (Mechanical) 25 Sep 14 16:03.

This tutorial is an educational tool designed to assist those who wish to learn how to use the ANSYS finite element software package. It is not intended as a guide for determining suitable modelling methods or strategies for any application. The authors of this tutorial have used their best efforts in preparing the tutorial. These efforts include the development, research and testing of the theories and computational models shown in the tutorial. The authors make no warranty of any kind, expressed or implied, with regard to any text or models contained in this tutorial.

The authors shall not be liable in any event for incidental or consequential damages in connection with, or arising out of, the furnishing, performance, or use of the text and models provided in this tutorial. There is no gaurantee that there are no mistakes or errors in the information provided and the authors assume no responsibility for the use of any of the information contained in this tutorial. In this tutorial you will examine the expansion of a pressure vessel due to an internal pressure using ANSYS. The problem is adapted from case study E on page 327 of the textbook Practical Stress Analysis with Finite Elements (2nd Ed) by Bryan J. You will determine the principal stresses in the pressure vessel due to the applied loading and boundary conditions. A two-dimensional plane strain element will be used for this analysis. We will use SI system units for this tutorial: length = m, mass = kg, time = sec, force = N, stress/pressure = Pa.

In this case the vessel is made from steel (E = 207 Gpa, v = 0.27) and the internal pressure is 10,000 Pa. Figure 1: Details of the Pressure Vessel - all dimensions in mm. There are standard theories available for the behaviour of thin and thick walled cylinders subjected to internal pressure.

These equations can be found in any text book on mechanics of solids or in any reference book. We can use these theories to predict the expected stresses in the pressure vessel due to the applied loading. The calculations for the various stresses is shown on pages 328 to 329 of Practical Stress Analysis with Finite Elements (2nd Ed) by Bryan J. Mac Donald and is summarised in the table below.

Figure 2 shows an overview of the plane strain model of the pressure vessel. The model on the left hand side is a full plane strain model of a slice through the pressure vessel. By recognising the symmetry in the problem we can reduce this model to a 1/4 symmetry plane strain model as shown on the right hand side of figure 2. In this tutorial, we will build the 1/4 symmetry plane strain model as it easily allows for the application of boundary conditions (which are not so easily applied to the full model). • Click Close to close the Element Type dialog box. Step 3: Define the Material Model • In the Main Menu click on Preprocessor >Material Props >Material Models, the Define Material Model Behaviour dialog box will now appear.

• Expand the options in the right hand pane of the dialog box: Structural >Linear >Isotropic • In the dialog box that pops up, enter suitable material parameters for steel ( E = 207 x 10 9 Pa, Poissons ratio = 0.27): • Click on Ok to close the dialog box in which you entered the material parameters. • Close the Define Material Model Behaviour dialog box by clicking on the X in the upper right corner.

Step 5: Create the Model Geometry • In the Main Menu click on Preprocessor >Modelling >Create >Areas >Circle >Partial Annulus • Enter the values shown in the figure below to create a partial annulus representing the 1/4 model of the pressure vessel cross section. • Note: if the background of your screen is black then that is not a problem. In the image above reverse video has been used. If you want to use reverse video (i.e. Have a white background) then simply go to: Utility Menu >PlotCtrls >Style >Colors >Reverse Video Step 6: Mesh the Geometry • In the Main Menu click on Preprocessor >Meshing >Mesh Tool • This will open the Mesh Tool window. • We are now going to use the Mesh Tool to set the size of the elements to all be a constant size before we begin the meshing process.

In the Mesh Tool click on Areas >Set as shown in the figure below. Step 7: Apply the Boundary Conditions • In the Main Menu click on Preprocessor >Loads >Define Loads >Apply >Structural >Displacement >Symmetry B.C. >On Lines • Pick the vertical line on the left hand side of the annulus and the horizontal line at the bottom of the annuals, then click OK in the picker dialog box.

• You should notice small 'S' symbols appear near the lines to indicate that a symmetry boundary condition has been applied. Step 8: Apply the Internal Pressure Load • In the Main Menu click on Preprocessor >Loads >Define Loads >Apply >Structural >Pressure >On Lines • Click on the curved line representing the internal wall of the pressure vessel and then click on OK in the picker dialog box.

• The 'Apply Pres on a Line' dialog box will now appear. Enter 10000 as the pressure value as shown below. Step 9: Solve the Problem • In the Main Menu select Solution >Analysis Type >New Analysis • Make sure that Static is selected in the dialog box that pops up and then click on OK to dismiss the dialog. • Select Solution >Solve >Current LS to solve the problem • A new window and a dialog box will pop up. Take a quick look at the infromation in the window ( /STATUS Command) before closing it. • Click on OK in the dialog box to solve the problem. • Once the problem has been solved you will get a message to say that the solution is done, close this window when you are ready.

Step 10: Examine the Results • In the Main Menu select General Postproc >Plot Results >Deformed Shape • Select Def + undef edge in order to show both the deformed and undeformed shapes. • Your screen should look something like this. Summary This tutorial has given you the following skills: • The ability to model plane strain problems in ANSYS.

• The ability to generate finite element models by meshing a solid model (in this case an area) • The ability to apply symmetry boundary conditions to a finite element model. • The ability to produce contour plots of stress in 2D plane models. • Experience in comparing the results obtained from your finite element model with other results and validating your results against the other results.

Log Files / Input Files The log file for this tutorial may also be used as an input file to automatically run the analysis in ANSYS. In order to use this file as an input file save it to your working directory and then select Utility Menu >File >Read input from. and select the file.

You should notice ANSYS automatically building the finite element model and issuing all the commands detailed above. Quitting ANSYS To quit ANSYS select Utility Menu >File >Exit.

In the dialog box that appears click on Save Everything (assuming that you want to) and then click on Ok.