I tried modeling a simple 4 point bending test in Abaqus, but unfortunately, the load-displacement curve was ascending and the crack and final load didn't match the experimental data. I used embedment for reinforcements and tied the supports to the beam. The load applied to the reference points which are coupled to the cylinders tied to the beam. I used different kind of steps like static general, dynamic explicin or dynamic implicit but the outputs was close to each other. Do you have any suggestion to solve this problem?
Dear Ali Shoari
please consider the following tips:
1- check the loading rates (Crosshead Speed) and also the material plasticity data.
2- try to increase your defined points in the plastic region, if you are using the elastic-plastic properties. Don't enter only a few points, maybe the nonlinear effects are very active in your material.
Generally this happen because of assuming perfect homogeneous material in finite elements analysis. While in reality there is a micro cracks, misalignment errors intest, lifting damage on specimens and so on. Try to accurate data input, specially stress strain curve, compression (cylindrical) and tensile strengths. In addition to eliminat pre-compressed stage from experimental curve
Try to input, plasticity region,
or in other methods, can simulate using static increment step to analyze crack phenomena.
Dear Mehran Shahpari
Thanks for your response, I will check them. Unfortunately, I use CDP in my model and I can't find proper data for that.
You mentioned crosshead speed. Does it cause any effect on the output for static, general condition?
Dear Abdullah Sikar Al-Issawi
Thanks for your tips. I use Concrete Damage Plasticity for concrete modeling. Unfortunately, there is no exact data for this material in the papers. I find some algorithms or simplified material behavior, but the output didn't change noticeably. Do you have any suggestions for this problem?
Dear Rizky Chandra Ariesta
Thanks for your response. As I mentioned before I used CDP as the concrete material; But there is no exact data for it and, I have to predict the data based on the compressive and tensile strength of concrete. Also, I'm not sure which step I have to use? (Static-general, Dynamic explicit or Dynamic implicit)
- Badges
- Science topic