Is it possible to set the separation force?

Mark Lin
Mark Lin Altair Community Member
edited January 2021 in Community Q&A

Hi all

As the title, I want know that if I can set a separation force between any contact surface.

In other ward, the contact surface be separated after bear a specific traction force.

I was tried to apply a normal force at the contact surface in first LoadStep, and the traction force will separate the contact surface in second LoadStep.

But in this case, my modal generated stress in first LoadStep, and I don't want this stress before I apply the traction force.

Can someone give me any suggestion? 

 

Answers

  • Gildas GUILLY_21156
    Gildas GUILLY_21156
    Altair Employee
    edited January 2021

    Hello Mark,
    What is the physical reason why the contact  would not open with light force ?

    - Is there something at the interface providing the unbonding (adhesive, glue...) ?
    If so, are you aware that modelling of "Cohesive zones" are available in OptiStruct ? You can use cohesive elements or cohesive contacts to model the damage to a bonding interface.

    - Is is due to some kind of preload ? (atmospheric pressure)
    If so using a preloading loadstep would be the option, but as you mensionned you will of course get resulting stresses I you would have in reallity.

    Gildas

  • Mark Lin
    Mark Lin Altair Community Member
    edited January 2021

    Hello Mark,
    What is the physical reason why the contact  would not open with light force ?

    - Is there something at the interface providing the unbonding (adhesive, glue...) ?
    If so, are you aware that modelling of "Cohesive zones" are available in OptiStruct ? You can use cohesive elements or cohesive contacts to model the damage to a bonding interface.

    - Is is due to some kind of preload ? (atmospheric pressure)
    If so using a preloading loadstep would be the option, but as you mensionned you will of course get resulting stresses I you would have in reallity.

    Gildas

    Hi Gildas Guilly, thanks for your reply

    Yes, That is similar to glue, thus I tried the cohesive contacts.

    But the cohesive contact is difficult to converge.

    Actually, I don't even know that if is the setting make sense, especially DMGEVO 

    Are there any example?  

     

  • Gildas GUILLY_21156
    Gildas GUILLY_21156
    Altair Employee
    edited January 2021
    Mark Lin said:

    Hi Gildas Guilly, thanks for your reply

    Yes, That is similar to glue, thus I tried the cohesive contacts.

    But the cohesive contact is difficult to converge.

    Actually, I don't even know that if is the setting make sense, especially DMGEVO 

    Are there any example?  

     

    Hello Mark,
    I jointed an example using cohesive interface.
    You can also loo at the knowledge base. There is a documents giving some ideas (KB0037668).
    Gildas