Cervenka Consulting Forums — apply cyclic load on reinforced concrete beam

Re: apply cyclic load on reinforced concrete beam

null@example.com (dpryl) — Wed, 24 Apr 2019 13:32:33 +0000

Dear Balvir Singh,
is there any specific reason why you are using quadratic tetrahedra elements?
Other than that, you can follow Troubleshooting, 2.1.1 to send us your model etc.
Regards.

Re: apply cyclic load on reinforced concrete beam

null@example.com (sandhu_balvir) — Tue, 23 Apr 2019 14:58:19 +0000

Hello sir
this type of problem/ error occurs after 14th step
x) CCFEModelExc: Negative or zero value of element Jacobian: -0.00262583, in element id: 13, group id: 410517505, name:
Quadratic Tetra elements(5402) for Macroelement 1
(x) CCFEModelExc: Multiple thread exception occured 1 times.

Re: apply cyclic load on reinforced concrete beam

null@example.com (dpryl) — Tue, 23 Apr 2019 08:30:34 +0000

Dear Balvir Singh,
1. for the most frequent sources of numericla problems, please see Troubleshooting, 2.4.6 Floating point problems - Division by zero, Loss of >7 digits on the matrix diagonal, CCFEModelExc: CCPardiso solver error: zero pivot, Warning: Sign of diagonal changed when reducing equation, Floating point exception: Multiple floating points traps, Zero or negative jacobian, InvertA: zero determinant, CCMaterials Extended AExc: CC5ParamYield F: project_stress_on_f_division by zero, and similar.

2. If you still can not solve the problem, you can follow Troubleshooting, 2.1.1 to send us your model etc.

Regards.

Re: apply cyclic load on reinforced concrete beam

null@example.com (sandhu_balvir) — Mon, 22 Apr 2019 15:59:05 +0000

Sir
i am facing some problem during analysis please help
1. this type of warning occurs during the analysis.
Warning: Sign of diagonal changed when reducing equation: 10891, (node: 13065, dof_id: 1); value : 53335.5.

2. As i am applying positive load only but in analysis showing negative load

Re: apply cyclic load on reinforced concrete beam

null@example.com (sandhu_balvir) — Fri, 19 Apr 2019 08:37:37 +0000

hello Sir
i tried my model for cyclic loading up to 25 mm deflection as per Atena manual 3.1.1 with increase of 5 mm after each cycle. results are not appropriate and shows no. of warnings. i want to model it for 13 no. of cycles(65 mm deflection with increase of 5mm in each cycle) but not able to understand the problem.

Can you please check my model?

Thanks and regards
Balvir Singh

Re: apply cyclic load on reinforced concrete beam

null@example.com (dpryl) — Tue, 16 Apr 2019 09:25:43 +0000

Dear Balvir Singh,
please first see ATENA Troubleshooting, 2.2.26 How can I model cyclic or fatigue loading? for basic related information (then, contact us to clear the remaining questions/unclarities).

Regards.

Re: apply cyclic load on reinforced concrete beam

null@example.com (sandhu_balvir) — Sun, 14 Apr 2019 07:42:06 +0000

Dear sir

i want to apply cyclic loading (Deflection controlled;
FIRST CYCLE( 0-5-0)mm,
Second cycle (0-10-0)
and so on up to deflection of 75 mm).
Please help to model

Regards: Balvir Singh

Re: apply cyclic load on reinforced concrete beam

null@example.com (dpryl) — Thu, 09 Aug 2018 14:00:07 +0000

Yes - please send us the model etc. (Troubleshooting, 2.1.1).

Re: apply cyclic load on reinforced concrete beam

null@example.com (ab1234) — Thu, 09 Aug 2018 00:37:35 +0000

Hi,

Thanks for the advice. but my deflection vs number of cycles graph is a strainght line which is impossible. could you help me to check the model.

with best regards

Re: apply cyclic load on reinforced concrete beam

null@example.com (dpryl) — Wed, 08 Aug 2018 08:30:54 +0000

Dear ab1234,
1. I recommend to also see the Fatigue example included in ATENA installation (%Public%\Documents\ATENA Examples\Science\GiD\Tutorial.Static3D\DirectTensionFatigue.gid).

2. Please keep in mind loads are incremental in ATENA (see also Troubleshooting, 2.2.15 How to model a load combination, e.g., a constant vertical force during horizontal displacement applied until failure?).

3. Please see also ATENA-GiD User's, 5.3.1.3 CC3DNonLinCementitious2Fatigue and 5.4.1 Fatigue.

4. For additional / background information, you can see ATENA Theory, 2.2.10 Fatigue.

5. If the problems persists or new questions arise, you can send us your model etc. following Troubleshooting, 2.1.1.

Regards.

Re: apply cyclic load on reinforced concrete beam

null@example.com (ab1234) — Wed, 08 Aug 2018 06:40:55 +0000

Hi,

Thanks for your reply. I have viewed the tutorials and followed them step by step, but the analysis was interrupted due to some mistakes that I cannot identify.
Last time I build a plain concrete model under static load and the result (loading vs deflection graph) was pretty good, this time I tried to build a steel fibre reinforced concrete under cyclic loading ( the load range was provided by my teacher), so based on my old model, I did some modification as listed below
1) change the 'Solid Concrete' properties into 'Cementitious 2', mateiral prototype 'CC3DNonLinCementitious2Fatigue' ( i am using atena science)
2) add a monitor for EXTERNAL FORCES at the loading point
3) add six internal data ( this process I am not sure if the interval multiplier and load steps are correct or not)
4) click on 'Write Fatigue Applied Cycles Monitor' in Problem data-> global options

Please let me know if there is any mistake about these four steps and anything i need to improve. since i have prescribed force level in each cycle ( 0 kN->22kN->40 kN ->11kN ->40 kN ->11 kN), I have no idea about how to apply these loads in the 'Interval Data'. If possible, could you please give me some advice?

with best regards

Re: apply cyclic load on reinforced concrete beam

null@example.com (dpryl) — Tue, 07 Aug 2018 09:20:59 +0000

Dear ab1234, please first see ATENA Troubleshooting, 2.2.26 How can I model cyclic or fatigue loading? for basic related information (then, contact us to clear the remaining questions/unclarities).
Regards.

apply cyclic load on reinforced concrete beam

null@example.com (ab1234) — Tue, 07 Aug 2018 00:51:31 +0000

Hi,

I build up a reinforced concrete model which similar to the example model in Atena Science tutorial. I would like to know how to apply cyclic load on the beam, the beam is under the cyclic load which is ranged from 21kN to 74 kN at frequencies of 3 Hz.

could you give me some hint about it ?

Thanks