error in equivalent static analysis to EC8

[patkson]

Hi all: According to the robot help manual

Base shear force is calculated according to the formula:

Fb = Sd(T1) * m * λ (4.5)

Sd(T1) - value of design spectrum of response for period T1 according to the point 3.2.2.5

m - total mass of the building according to 3.2.4(2)

λ - correction factor, (0.85 or 1.0) set automatically basing on the Clause 4.3.3.2.2

However I notices that the correction factor λ 4.3.3.2.2, is wrongly used by robot. I have done several models making sure that my

T1 is > 2TC (eg 1.6s on type B ground) but robot still uses 0.85 as λ. This result in wrong Total seismic base shear.

The last thing has to do with the value of Ct=0.05 for other structures. I have noticed a typo in the calculation report as the robot still records 

a value of 0.09 for other structures this is very confusing. (this has to be corrected)

I will kindly need some clarification on the issues raised above.

Thank you.

Regards,

pok

[patkson]

error in equivalent static analysis to EC8

Hi all is not just NBCC 2010 but also the EC8.

According to the robot help manual

Base shear force is calculated according to the formula:

Fb = Sd(T1) * m * λ (4.5)

Sd(T1) - value of design spectrum of response for period T1 according to the point 3.2.2.5

m - total mass of the building according to 3.2.4(2)

λ - correction factor, (0.85 or 1.0) set automatically basing on the Clause 4.3.3.2.2

However I notices that the correction factor λ 4.3.3.2.2, is wrongly used by robot. I have done several models making sure that my

T1 is > 2TC (eg 1.6s on type B ground) but robot still uses 0.85 as λ. This result in wrong Total seismic base shear.

The last thing has to do with the value of Ct=0.05 for other structures. I have noticed a typo in the calculation report as the robot still records 

a value of 0.09 for other structures this is very confusing. (this has to be corrected)

I will kindly need some clarification on the issues raised above.

Thank you.

Regards,

pok

[patkson]

Hi all is not just NBCC 2010 but also the EC8.

According to the robot help manual

Base shear force is calculated according to the formula:

Fb = Sd(T1) * m * λ (4.5)

Sd(T1) - value of design spectrum of response for period T1 according to the point 3.2.2.5

m - total mass of the building according to 3.2.4(2)

λ - correction factor, (0.85 or 1.0) set automatically basing on the Clause 4.3.3.2.2

However I notices that the correction factor λ 4.3.3.2.2, is wrongly used by robot. I have done several models making sure that my

T1 is > 2TC (eg 1.6s on type B ground) but robot still uses 0.85 as λ. This result in wrong Total seismic base shear.

The last thing has to do with the value of Ct=0.05 for other structures. I have noticed a typo in the calculation report as the robot still records 

a value of 0.09 for other structures this is very confusing. (this has to be corrected)

I will kindly need some clarification on the issues raised above.

Thank you.

Regards,

pok

[Artur.Kosakowski]

What is the number of the stories in your model? Could you attach it?

[dimogrec]

Hi Artur,

I think the answer on your first question is shown in the attached pictures (model 1 ->14stories,  model 2 -> 24stories)

[Artur.Kosakowski]

Thank you - I missed this 

[Artur.Kosakowski]

However I notices that the correction factor λ 4.3.3.2.2, is wrongly used by robot. I have done several models making sure that my

T1 is > 2TC (eg 1.6s on type B ground) but robot still uses 0.85 as λ. This result in wrong Total seismic base shear.

As your model seems to have more than 2 stories could you attach it please? 

The last thing has to do with the value of Ct=0.05 for other structures. I have noticed a typo in the calculation report as the robot still records 

a value of 0.09 for other structures this is very confusing. (this has to be corrected)

I have asked the development team to investigate this situation. Thank you for reporting it.

Thank you.

Regards,

pok

---

[patkson]

Hi Arthur,

I have attached the two models without results as you requested.

And a quick comment, this error is been repeated in the 2015 version.

Please you and your crew should do something about it.

Thank you.

[patkson]

Test model two

[Artur.Kosakowski]

Thank you for the files. The issue is under investigation.

[patkson]

Hi Artur,
Is getting to two weeks now since I raised the issue above and still haven't heard anything.
Are the team looking into this at all?????

[Artur.Kosakowski]

The correction is planned for SP2 for Robot 2015.

Please note: Our quality assurance teams may need to reschedule some fixes. Please rely on the above timeline information as a guideline only and not a guarantee. We appreciate your understanding in this matter. 

[Artur.Kosakowski · Accepted solution]

Corrected in Robot 2015 SP2.

[patkson]

ok great I will check it out then..

thx for informing.

[patkson]

please what's the link to the SP2

[Artur.Kosakowski · Accepted solution]

It will be available in few days under this link.

[patkson]

Oh yes is been indeed corrected. Kudos to the RSA team. this phenominal!!