contact
contact
(OP)
hi,
any idea what went wrong with my model? i simply put 2 plain concrete block (150 x 300mm) together, and put spring between them (as contact), my main porpose is to make sure that the 2 blocks will act as one single block (150 x 600mm), but by checking the deflection (after the matching)compare with simple hand calculation, it doesn't seem what i have done to the contact part is right.
please advise.
any idea what went wrong with my model? i simply put 2 plain concrete block (150 x 300mm) together, and put spring between them (as contact), my main porpose is to make sure that the 2 blocks will act as one single block (150 x 600mm), but by checking the deflection (after the matching)compare with simple hand calculation, it doesn't seem what i have done to the contact part is right.
please advise.





RE: contact
I'm not sure exactly what you're trying to do as you define contact and yet have springs between the two bodies. I don't see the need for the predefined temperature field of a constant 20C either, but neverthelesss.
Looking at the displaced shape, the top body has moved down a distance, probably an amount given by the spring stiffnesss. If you want the two to move together then you'd need a bigger spring stiffness or just do away with the springs altogether and move the two bodies together in the assembly module and have contact.
Is there a need for finite sliding in contact as the two won't slide across each other?
corus
RE: contact
RE: contact
corus
RE: contact
what if i have a composite structure (concrete slab on top and I-section at the bottom, shear stud in between the slab and beam to connect both components).
I will apply tie constraint between the slab and beam surfaces, so that the 2 components will act as a single composite structure (assumed full interaction between both component, where slip=0 everywhere), correct me if i am wrong.
If i would like to consider the shear force in the stud connectors, i have to apply *spring2 or *springA between these 2 components, and set the DOF along the direction of the beam.
please advice.
RE: contact
corus
RE: contact
if i use beam element as you said, what length should i specify for the beam element between the 2 nodes (slave and master)?
possible to attach the *.inp of the model that u mentioned? which use beam elements to represent the studs.
RE: contact
corus
RE: contact
I trying to use beam elements as you suggested, I tied the beam elements on the top flange surface, but how could I tie the other end into the concrete slab? as Abaqus only allow me to select nodes on the surface of the component, not inside the component.
beside, do i need to define the 'surface to surface contact', for both the slave and master surface of the section (i.e master = top flange of I-section, slave = concrete bottom surface). please advice.
RE: contact
As you say, define the master and slave surfaces as the top of the flange/bottom of the concrete. For contact the master surface should be the harder of the two materials, which in this case will be the steel.
corus
RE: contact
have you done any model for concrete material has run sucessfully in Abaqus? as i defined my concrete material properties by using *concrete keyword (case 1), i need to define the *tension stiffening as well, i used concrete softhening stress-strain curve, but Abaqus couldn't finished the analysis. So i use *elastic, *plastic keyword (case 2) to define the concrete material (i ignored the softhening part, let the plastic stress remain constant after reaching the concrete maximum stress) as what i have done to define the steel properties, Abaqus run longer than before. the thing is i could only define the concrete compressive part in case 2, but not the tension part. do you think this is the 'right' way for concrete material analysis? please advise.
RE: contact
corus
RE: contact
RE: contact
corus
RE: contact
as the earlier reply (27 Feb), you mention that 'you used cast iron type behaviour to describe different yield properties in tension and compression', what do u mean by 'iron case'?
beside, u ignored tension in concrete strength in tension, was that mean u didn't apply any tension stress- strain curve in your model? and you were also using the *elastic & *plastic keywords to define the concrete properties?
RE: contact
corus
RE: contact
by the way, in the *elastic, there are options 'No compression' and 'No tension', if I click on the 'no tension' button, is that mean Abaqus will not consider the tension stress- strain curve? if i use the *elastic and *plastic to define my concrete properties, than i will only have the concrete stress-strain curve.
please advice.
RE: contact
In any case try the 'no tension' option, which presumably does as it says, and doesn't consider the material in tension. Your stress-strain data will then apply only in compression. The best thing you can do is to run the analysis and see if the results you get make sense and the material behaves as you expect it to.
corus