Imrose B. Muhit @That's my though as well, but I couldn't solve the issue yet I am still struggling defining the material property to allow the analysis to run.

I am using a Macro modelling approach. While the model type I am considering is a nonlinear plasticity model as far as I know.

Best,

Hello Ali Gamra ,

If there is something you must always do with modeling, it is to proceed by steps and not trying to model asap what you want. Test the different elements one by one and you will see what is wrong. As suggested above, it may be the masonry the problem. Once the simple models are sure to work, model with more complexed laws.

Hello Damien Decret

Thanks for the advice, as I mentioned above the issue is most probably related to the definition of the material property, specifically when I define manually the Stress-Strain constitutive relationship of the material. Also, from literature, I found that many authors mention the values of cohesion and friction angle in relation with the modelling stage, but I cannot find any window in SAP2000 allowing me to insert the values. I read from SAP manual (Correct me if I am wrong) that SAP does calculate the shear strength of the material internally based on the input of Stress-Strain relationship mentioned before.

These are two questions and if I can get a concrete answer my problem will be hopefully solved.

Thanks in advance.

Hello Ali Gamra ,

If you define your material for shear, make a pure shear test on SAP to your material to be sure you defined well the material before using it in a more complete model. By doing this you will know asap if your definition of the material is wrong. What kind of material law do you use? Mohr-Coulomb type?

I am not a SAP user but I think that you just do not use the same constitutive law as the one used by the authors. Be sure you are using the same constitutive law and that the authors did not make their own constitutive law. For your question about the calculation of the shear strength, I think that the software calculate it based on your stress-strain relationship, it would be the more logical thing for me. One thing you have to be aware of as well, is that sometimes models use parameters that can be defined in different ways. For example, if you define a shear modulus in your model but if your shear-strain constitutive relationship does not have the same shear modulus initially, your model will not work.

Hi Damien Decret ,

First of all I am really appreciating your help and the explanation of things.

Secondly, as you have mentioned since the shear strength is calculated internally using the Stress-Strain constitutive relationship then I presume that the shear is calculated once the constitute law is sat? So all I have to do now to carry out a shear test on a simplified model and compare the results with the equation? In literature most of what authors use is the Mohr-Coulomb equation (For shear) yes. but I am not sure what SAP by default uses to define the shear strength, I may find this in SAP documentation.

Thanks for the awareness! I was aware of it when generating the Stress-Strain curve to make sure that the elastic modulus would match the elastic range of the curve. But did not do the same for the shear modulus. It may be different? I will definitely check!

Imrose B. Muhit Absolutely! Thanks for the advice, I think it's the ideal strategical approach to solve my problem.

Not an expert but always be cautious when you treat shear strength in SAP2000 things get tricky sometimes

Hi Mohamed Afifi and sorry for my late reply.

In what way tricky do you mean, where in particular?

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