Hi everybody
I am trying to simulate seismic behavior of reinforced concrete cantilever column. A constant axial load is applied at the free end of column. Lateral loading is a cyclic displacement that applies near the free end. I want to derive load-displacement hysteresis loops. I use Mat _ Winfrith (mat084) for concrete modelling. To consider the effects of concrete crushing in compression I defined MAt_ADD_EROSION with minimum principle strain at failure (MNEPS) as an erosion criterion. According to attached file the deformed shape of column is completely illogical.
Can anyone please advise on this?
@mahmoud I have not had the chance to look at the job but, clearly, the results make no sense. Seeing the elements fly away makes me think that the input acceleration is too high which suggests the rate of loading is unrealistic. Use a smooth spline (or whichever function you prefer) to prescribe the loading so that the acceleration is physical. Now, it may turn out that the time scale is too slow and, if that is the case, then increase the mass scaling as long as the ratio of physical and non-physical energies continues to make sense.
@icebreakersours this modeling is intended to validate an experimental test. The loading protocol is also selected from the same experimental work.
I solved the problem of irrational erosion of elements by selecting a larger value for the MNEPS criterion. But the load - displacement hysteresis curve is very uneven( please see the attached file) and very different from experimental results. Please leave your valuable comments to solve the problem.
Thank you.
I suggest you take a step back and focus on getting the basic physics right first. Ignore the material erosion and just get the basic linear elastic or elastic plastic material to load at the right rate and digest the post-processed results. If those do not make sense, results from a relatively complex analysis have no chance of making sense.
@icebreakersours Thank you for your suggestion. Please check modeling file if possible. 😟 😟
There is a lot going on in the model so, unfortunately, I will not have the time to look into it. Now, that said, I noticed a *CONSTRAINED_LAGRANGE_IN_SOLID card in there. My understanding was that *CONSTRAINED_BEAM_IN_SOLID has superseded the *CONSTRAINED_LAGRANGE_IN_SOLID feature. Check the manual and be sure that is indeed the case and, if it is, then consider switching the card.