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Found 35 results

Hello everyone: I've been trying to do the optistruct tutorial OS-T: 1340 Fatigue (Stress - Life) Method but I'm new in this area and I have some questions about FATLOAD and its parameters. What exactly is LDM and what realitonship has with the load of the subcase? I've seen that loads for each subcase are respectively 1250 N and 1000 N. However both load histories are between 1 and -1 and with a scale of 3. Why is like that? Shouldn't it be with a scale of 1000 one and 1250 the other? In the case that instead of a punctual load there's a pressure or moment in one subcase, load histories need to be scaled to N to be consistent or they can stay in the units of the subcase load (Nmm or N/mm^2)?. How would you represent in the fatigue analysis static loads that contribute to the stress of the model but don't vary cyclicaly? I appreciate your time answering them.
2. ## Fatigue Analysis on Lattice Structure

Hı everyone, I want to do fatigue analysis. After Lattice Optimization, my model has 1d beams. How to convert from 1d element to shell element. Thank you
3. ## Can we define material property in Tabled Type of Fatigue?

I know we can set material property of fatigue in MATFAT. And we can set the SN curve points of the material. I am curious about can we use the TABLE's type to import our material data in fatigue material? Because at the thermal we can do for this. And I also have problem about the FATPARM's instruction of COMBINE what is "SG" mean? Because I have seen it shown like the photo and it also written in SGVON (SG von-Mises)
4. ## fatigue Fatigue analysis

Hi to everybody, i would like to perform a fatigue analysis using this method: -run the dynamic analysis in Motionsolve in order to extract the load spectrum -run the fatigue analysis in Optistruct using that load spectrum the problem is that the dynamic analysis needs 150000 seconds, and this means an enormous amount of time in Motion solve,it's almost impossible. So is there any other way i can perform this type of analysis? Thank you.
5. ## What dose FATLOAD Parameter mean?

I am doing the fatigue practice and at my practice file. I don't know what FATLOAD mean exactly. For example if our model today will subject a F=100N At TID I know we need to set the TABLE to input and when I plot the .csv file I seem it look like the Load Time History photo. So it this mean our total time is 2500 sec? And the load have positive and negative for scale 1 and -1? (At here our model will subject 100N & -100N for 2500sec) And the LDM I just can't know about it. Finally what is mean for the SCALE? Because we have load time history we can see our load is for 1 and -1. At here we set 3 so that means out load will scale for 3? (Final it will ill subject 300N & -300N for 2500sec)

Hello, I am doing fatigue analysis using SN life approach....I wanted to know what is the effect of frequency of loading cycle on fatigue life and damage? For example if the frequency of load cycle is doubled what will be the life and damage? Thanks in advance.
7. ## Fatigue analysis

Hello, I am working on Bracket for which i have conducted FRF analysis. Now i what to carry out Fatigue analysis for that one at particular frequency before resonance. How can i carry this analysis now. Thanks in advance for Reply
8. ## Ceramic Fatigue Analysis

Any Idea, how one can perform fatigue analysis of structural ceramic materials? Thanks.
9. ## SWT equation (fatigue module) misspelling on hyperworks help

Hi...I figured out misspelling on hyperworks help "fatigue analysis" On optistruct fatigue analysis help SWT equation is missspelled.
10. ## Fretting Wear Simulation

Hi, I want to simulate fretting wear on a cylindrical roller bearing in HyperWorks. Example: McColl, I. R., et al. (2004). "Finite element simulation and experimental validation of fretting wear." Wear 256(11–12): 1114-1127. Could you please help me how to proceed? Thanks Arjun
11. ## Life -> year, month

以前のBlog投稿（https://web.altair.com/altairjapanblog/hyperlife-fatigue）の最後のほうに出てきたスクリプトになります。 表示されているNoteを消すボタンを追加しています。 使い方は https://web.altair.com/altairjapanblog/hyperlife-resultview の最後のほうに書いてある方法と同じです。 life_convert.tbc

Hi, I am trying to learn fatigue using optistruct , Please share me with the videos and fem files regarding fatigue. I already went through the fatigue tutorials in optistruct If I put all of the fatload into one fatevnt, are they now occurring simultaneously? How do I change the model that the loads occurs one after each other? Thankyou N.K
13. ## FATLOAD with LCID entry

Hello, for a Fatigue Analysis I am using the LCID entry to refer to a transient reponse load case to evaluate stress history. My question in which manner the stress history is processed. If the Fatigue LC reads stress from h3d-file the output frequency for transient response analysis is very important. Thanks for your comments. JD
14. ## How to setup a fatigue analysis using acceleration as load?

Hi, I'm trying to run a fatigue analysis using acceleration as load, but I don't know how to set the FATLOAD card with an acceleration load. My objective is to simulate a shacker test and verify the life and damage that the part will get when vibrates in 1G acceleration. Modal and frequency response analysis are ok, my only problem is with the fatigue analysis. If anyone knows how to proceed, please let me know. Thanks!
15. ## Error in Seam Weld Fatigue Analysis in Optistruct

Hello ! I am new to fatigue analysis in optistruct. For reference, I have followed the instructions as provided in the help file and with the same model as used in there (link has been provided for reference). I have been facing analysis failure with error code #6971. I have attached the screenshot of the error. Can anyone state the possible cause for this ? Help File Link : https://altairhyperworks.com/hwhelp/Altair/2017/help/hm/hwsolvers.htm?fpm_en_strain.htm Regards Venkatesh
16. ## What types of analyses are performed on a truck's propeller shaft?

A propeller shaft experiences opposing torques on its ends, while rotating. What types of analyses are generally carried out on a propeller shaft, apart from static, modal, fatigue? What are the reversing loads to be given in a fatigue analysis? (The only reversing force that comes to my mind is the shaft's self weight, acting sinusoidally. Are there any other reversing loads in a rotating shaft?)
17. ## Fatigue analysis MATFAT parameters

@Prakash Pagadala @Rahul R Hello Sir, I have doubt regarding MATFAT parameters in opti. Can you please tell me the SRI1, b1, Nc1, FL parameters values for following Material stress data: Alternating Stress(Amplitude) Life 4000 MPA 1 855 MPA 1000 86.2 MPA 1000000 86.2MPA is the fatigue strength/endurance strength of the material. Please guide me to calculate the MATFAT parameters from given material data. I am confused about where to double the values for stress range and where not to. If you will elaborate with the given data it will help me a lot. Kindly reply at your earliest convenience. Thanking you in anticipation. Regards, omkar Bhumkar
18. ## FL value in MATFAT

Hello, In fatigue analysis in Optistruct, Do we also have to multiply the fatigue strength value by 2 while defining FL in MATFAT like we are doing for SRI1 value?(stress range= 2* stress amplitude) e.g if the fatigue strength of a material is 100 MPA then do i have to put 200 for FL in MATFAT? TIA
19. ## Fatigue life calculations

I came across in the documentation that the life is calculated using the formula. Sr = SRI1(Nf)b But, even after maintaining the co-efficients, TRTMENT, FINISH and [KF] as 1, the results are off (when compared with the manual calculation using the above mentioned formula) by a random factor (approximately 0.5), for each unique component I take for fatigue analysis (Refer image attached). Why is it so? What is the calculation happening at the back end of the software? Why is the factor 0.5 coming into play?
20. ## Random Response Fatigue Analysis

Hello guys, I made an example of Random Response Fatigue Analysis. There are three loadstep in my model and there are FRA, Random and Fatiuge. the results of first two Loadsteps are not error. Though the fatigue subcase can run ,there is no any result in the subcase。 Lcid card refers to the Random subcase. And the Tid card is blank. the PFAT card was estimated by UTS. Would anyone can fix the problem out? 1pl.fem
21. ## Fatigue Analysis Optistruct

In a fatigue analysis setup in optistruct solver is it absolutely essential that the component to have no life (fatigue failure) if : - static analysis stress exceeds ultimate tensile strength of material component. - load time history 1 cycle is 0 1 0 Please provide some clarification regarding this matter.
22. ## Fatigue Analysis

what material property are required for fatigue analysis ?
23. ## Strain-cycles (EN) Fatigue analysis

I was trying to do Fatigue analysis (EN) in Optistruct according to the tutorials for Strain- cycles (EN) analysis. I gave input load time history table for the load from the tutorial folder (in C drive). I got an output as damage (s). But I want output as no. of cycles. How will I get that? In experimental constant strain controlled fatigue test, we perform the test for different strain amplitudes and we will get corresponding cycles of failure. I want to replicate the same in Optistruct. Is it possible in it? Please help me out. I am doing the analysis with standard tensile test specimen. Thanks in advance.