how to use Plastic material property of steel only

[muhammadaziz.sarwar]

I am working on composite pipe haveing steel wires as reinforcment and rubber.Query1: I want to simulate only plastic deformation .I tried to use voce law but it activates at certain increasd pressure. Not at low pressure where we have less stresses developed .I tried with prestress equal to yield stress so voce law activates but a lot more deformation observed.Suggest  me any material which gives me directly plastic propety of steel.I have uniaxial experimental data of my materials.Query 2:I want to apply working pressure and burst pressure in mechanical apdl ? is it possible to apply in  working pressure and burst pressure because working pressure involves pressure applied for soem minutes and burst pressure includes pressure applied in steps then keep applying each pressure for some time ?

[John Doyle]

You might consider using reinforcing elements REINF264. Ansys supports two methods for modeling reinforcing cables or fibers: Discrete Reinforcing and Smeared Reinforcing .  Refer to Section 5.5. Reinforcing Elements  and REINF264 of the MAPDL Elements Reference Manual for details.   You can also use INISTATE to introduce prestressed condition in the rebar.  Loads and BCs can also be applied in MAPDL as functions of time. 

If you are defining time dependent loads, I assume you need rate dependent material properties.  Without rate dependency defined in the materials, your time dependent load history will not produce any relaxation or creep.  A rate dependent material response can be included in both the hyperelastic material (for the base rubber) and also in the reinforcement, for the steel reinforcement.  The material model combinations needed depends highly on the test data that you have available and the complexity of the load history.  I would start with a review of the Viscoelastic Prony Series (superimposed on a rate independent hyperelastic material) for the rubber material relaxation (if necessary) and a rate dependent creep material model (superimposed on a metal plasticity) for the rebar.  See MAPDL Material Combinations   of the MAPDL Material Reference Guide, for more details.  

[muhammadaziz.sarwar]

Thanks for detailed response.Okay thank you so much for your reposne i am using smeared reinforcment could you please tell me selecting base elements are not enough if we want to reinforce full base element with smeared reinforcment for 3d base element beacuse i think.i am using element face,but i am not sure my full base element is reinforce as i am recieving less strong base element against the material property of reinforcemnt please explain about equivalent thickness and role of element face.. If we want to reinforce full base element for example 1mm thickness how many layers or role of area of fiber and distance between themREINF265. For material properties ..I am confused to use voce law ...for elastic results..and could you share any documnet when materail hardening parameters starts to work for example elastic to plastic transition ? could we control that elastic to plastic transition to check desired output.Thanks again for your response.