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Udin, April 14 in Altair OptiStruct
What type of analysis is it?
Is it is a static analysis, it is no possible to get load vs history plot.
Try transient analysis or any dynamic analysis type.
yea i already got the load time history. I have 2 question, after i have followed the controlarm for stress-life (fatigue life) and applied the method to my leaf spring Steel , my lsteel leaf spring fatigue life is very small. could you help me with this sir ?
@Udin how did you apply the load?? And i recommend you to go for a static analysis with maximum load and evaluate the stress under static condition for maximum magnitude of load. You can also evaluate the signed von mises stress and evaluate the mean and alternating stresses.
I hope you gave a magnitude and normalized tabled data while giving fatigue loading.
The load i create myself and i took from the applied load of the centre leaf spring which is 9810N. I should take the von mises stress as my load? ohh i see we need to find the mean stress from signed von mises?
the data i made by microsoft excel
So while applying the load did u again gave a value of 9810?? If so give it unity. Or else normalize this loading curve and give load as 9810!
yes i gave the value as 9810 in load time history files (*csv). Sir how to normalize this loading curve?
If you give this as tabled data and again apply a reference load of 9810 your total load at time=2 will be 9810×9810 which will be huge.
ohhhh, thts why the fatigue life is little. do you have recommendation for the load time history values?
You make like this
Time=1 load =0
Time=2 load = 1
And alter every value of 9810 with 1
And then apply reference load of 9810.
thats make sense, thank you very much Sir i will try to do your steps
Sir what about the left handside table, the LDM and Scale need to change too ?
Dont alter it as of now. You proceed and apply a refrence load of 9810N.
For more details on scaling and LDM you may refer reference guide under help.
The result is still small as the previous ones sir
Can you do a static analysis for the same with load of 9810N and check the signed vonmises stress??
yes the static
the static result for signed von mises
The stresses are quite high kindly check for BC and load. Also check the unit consistency i recommend you to follow tonnes mm system.
okay thats means i need to change from 1600kg into tonne=1.6 then convert it into Newton=15.696N. is it? if i use this value my vonMises is 7.99E+1 but the fatigue life is still small value which is 0.04.
I mean in what unit system you gave young's modulus and density.
thts means its starts from solidworks unit scale ? if in solidworks i set to mm , than i need to use the ton,mm,s,N,Mpa, Demsity = 7.83e-9 , Young's = 2.07e+5 , Gravity = 9.806e+3 ?
Yes this should be the unit system.
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