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Cyclic Plastic Analysis

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engeserv03

Mechanical
Mar 16, 2008
5
Hello,

I would like to develop a simulation to a carbon-steel pipe (A106B) which has a cyclic loading temperature ( 21oC to 300 oC to 21 oC )due this loading, restrictions and stiffiness are got internal stresses and in someplaces in this pipe (curves) the local level of these stresses are above yelding point.

My goal would be to verify if this level of stresses can decrease with pass of cycles ( after 10 for ex.) due to cyclic elasto-plastic effects (stress re-distribuition,relaxation,shakedown, etc.)

Reading the Abaqus manual, I could verify the simulation resources to apply "isotropic or kinematic hardening to cyclic loadings " but I am having very difficults to get and apply correctly the "material parameters" or "option configuration" for this.


How I said aboveI would like to verify if the level stresses decrease after some temperatures cycles due to elastic-plastic effects or not.

The material is a carbon steel pipe ASTM A106B which has
tensile strenght= 42 kgf/mm2 , yeld strenght = 24,6 kgf/mm2 and the max. elongation = 26%

I tried to apply in Abaqus 6.5.1, the following properties sets:

Plastic>Hardening=Combined
Data Type=half cycle
Suboption: Cyclic hardening
Values
1)yield stress = 24,6 plastic strain = 0 ( kgf/mm2)
2)yield stress = 42 plastic strain = 0,26

and the same values to "equiv stress" and equiv plstic strain"

With this inputs, I could get the residual stresses, the final stress ( = yield stress) but the stress values did not change after 10 cycles.

I think that the inputs values are not suitable for this kind of simulation.

If I to work with, Hardening > Combined
Data Type > Parameters

I need to inform: "yeld stress at zero plastic strain" and
"kinematic hard parameter C "

The first value I have but the parameter C is very difficult to get and I am not sure about this procedure.

If someone had similar experiences and could give me an orientation I would be very gratefull.


Thanks







 
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engeserv03,

I would like to make a suggestion to you. All members on this forum are volunteering information to help each other. However everybody has a limited time. If you could abbreviate your questions, it will help you in getting more responses.

As regards the question about parameter C, are you a member on the ABAQUS website? This problem is covered in their answer no. 3099.

Gurmeet
 
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