mander et.al cyclic modeling

[mohamad reza]

hello

dear seismosoft

i use mander et.al model for concrete material both for confined and unconfined .but i have confused in cyclic modeling curve .there is the sample cyclic curve according to j.Eneique and A.S.Elnashai model (that is addressed in help in mander.et al )in program . is this cyclic curve modified automatically for any concrete with any property or not? should i define this curve by myself? or it is not essential define this cyclic curve and program can modify this automatically?
i checked this cyclic curve ,it is drawn for unconfined concrete just for strain .002 at pick stress, is it true?.

please help me i really have confused how can i correct this curve for confined concrete .

thank you

[Sara]

The curve is updated anytime you enter a new value (for any parameter) or when you change it. You do not need to define the entire cyclic curve by yourself.

The default curve is given for peak stain equal to 0.002 (for unconfined concrete - using the wizard), but you can notice that, changing that value, the curve is modified as a function of the new entered peak strain value.

[mohamad reza]

thank sara, have you ever worked with this model for nonlinear analysis ? i fell that it is not true for confined . the sample is only correct for unconfined and only for peak strain at 0.002 .yes i saw when you change confine factor rather than 1 the curve changes but in confined concrete the peak strain is different according to mander et.al model and the ultimate strain too.i changed the strain peak to .0053 shape of curve changed ,however that is not similar to shape that is announced in j.Enrique et.al paper(this paper is introduced in help for cyclic modeling). if you have project that you have done before and you sure about that ,could you send it to me or an example that could solve my problem ?

thank alot

[seismosoft]

Dear mohamad reza,

We confess not to fully understand your query, but, if you have doubts on the cyclic laws being adopted by the program during a given analysis, we suggest you to create a simple model consisting of a single element subjected to cyclic axial compression, and check the strain response history for different input properties.

Seismosoft Support

[mohamad reza]

thank you seismosoft for your attention.my problem relate to the define concrete material model .in program there are many model and i have chosen Mander Et.al model for concrete members .if you chose this model see sample curve for cyclic model of mander i do not know this plot which you have drawn in program is just sample or not it is real model? i do not know cyclic curve in program is drawn base on what strain at peak stress .was this curve drawn base on confine concrete model ? or not was drawn base on unconfined? please tell me should i define new cyclic plot(strss-strain) for confine concrete or not? i really have confused i want to use mander cyclic model for confined concrete. for this reason i calculate confinement factor and strain at the peak stress(fcc),and i enter those parameter in to the related box in material properties in program and after that blue plot changes . dose this modified curve correct for confined concrete or not?

my whole problem is

can be sample plot modified automatically for confine concrete or can not? and if can be modified automatically by program with entering new parameter in confinement factor and strain at peak stress ,will this modified curve correct or not?

[seismosoft]

Dear mohamad reza,

We maintain what we said already; if you run some analyses using a single element subjected to cyclic axial compression, you will readily find the answers to your queries or doubts.

Seismosoft Support

[mohamad reza]

hello again seismosoft

can this cyclic model(mander et.al) consider bond slip and shear and diagonal crack effect substantially in program? if this model dose not comprise those effect ,what model do you suggest in program which can consider those effects?i want control plastic rotation cause by effects which i mentioned above in members


thank you

[Sara]

Dear mohamad reza,

Check if these following forum discussions are helpful for your purpose:

http://www.seismosoft.com/forum/topic.a ... =bond,slip

http://www.seismosoft.com/forum/topic.a ... hTerms=bon