Interaction between steel and concrete in ABAQUS

[Ali asger]

Hello There, I am a student working on abaqus modelling of a composite deck slab for four point bending test as per eurocode 4, i have modelled concrete as solid element , steel as shell element and i have provided boundary conditions using rigid tie constrain the faces of concrete and steel at a node and applying boundary conditions of pinned and roller on two ends , further i have applied surface to surface interaction standard using both normal and tangential behaviour , loading i have apllied using a coupling the load line to a centre point on top of slab and assiging displacement of 15mm , the issue i am facing is that the steel is getting separated from concrete and the bending is not correct as given in image i have attached , how can i fix this please help and further i have seen that by changing the way i am applying the load the initial stiffness of the slab changes i dont know why ? please someone can suggest me how to fix this errors Thankyou



Thankyou

 

[FEA way]

How did you tie those parts ? On the whole surface or only on the sides ? Some screenshots with the BC/load/constraint symbols would be helpful.

 

[Ali asger]

Thankyou for your reply sir, please find below attached images , in 1st image i have used rigid tie constrain on the face of concrete as well as steel deck and choose a control point , on that control point i have applied my boundary conditions. In image 2nd i have applied a displacement of 20mm using coupling the loading lines to a center point on top of slab. Hope this will give you a clear idea what i have modeled. Thankyou


Thankyou

 

[FEA way]

So you don't have a tie constraint - only rigid bodies with tied nodes. You should also apply a tie constraint between the shell and solid if they are supposed to be permanently bonded on the whole interface.

 

[Ali asger]

i have applied surface to surface contact using penalty friction of 0.5

 

[FEA way]

Replace it with tie constraint or tied/cohesive contact if you want them to move together without separating.

 

[Ali asger]

actually in my case i want to study the slip behaviour of slabs, apart from this actually i rectified i error while using surface to surface interaction and now the steel deck is not getting separated but the slab is unable to predict the initial stiffness correctly , any tips what i should do to correct my results?


Thankyou