Autodesk Robot Structural Analysis

[#1]

In the attached file, I have calculated the required reinforcement for RC-Wall using (ACI318-08M), for first run without using the Amin , I found out that in the vertical reinforcement, the required steel area is less than the minimum ,after that I used in the second run Amin for finite elements, their steel area is less than minimum and greater than zero but I have noted that ROBOT used twice the steel area minimum for some finite elements .

This is what we see from your explanations and screen shots:

- capture1 - reinforcement without Amin - results displayed for elements where the reinforcement is calculated = required , 

- capcture2 - calulated with Amin - it seems everywhere you should use min reinforcement = 40cm2 but for some elemnts it is reported as 40 on one side (+ or -) or splited between two layers (20+ and 20-), why - we will check codebook and explain later.

[#2]

Dear Rafal

Explanation , I would like to thank you for your response  .But, actually  I am calculate the reinforcement for RC-WALLS using this way because I couldn't able to use RC-WALL module to calculate provided reinforcement since ROBOT always generate edge reinforcement for all cases using ACI318-08M ,but in some cases we don't need this "edge reinforcement )depended on the seismic zone . so, I hope in the next ROBOT version the developers will consider this point .

However ,

If you use the option " Minimum reinforcement  for the whole panel " you will find the Amin = 20 cm2/m . It means that ROBOT use Amin= 0.005x40x100 = 20 cm2/m for vertical reinforcement where wall thickness=40 cm.

But ,since I am designing RC-wall , the minimum reinforcement for vertical side as ACI318-08M ,clause 14.3.2 depended on "Fy ".for my case "Fy= 400 Mpa" then Amin=0.0015bh =0.0015x40x100=6cm2/m. It means not "40 cm2/m or 20 cm2/m"

Then , in my point of view , ROBOT should know firstly the panel is slab or wall because each one of them has a different  "Minimum reinforcement ".

Kindly , correct me if  my thinking is wrong . I am awaiting your confirmation.

Note : Attached is ACI-code page related to minimum reinforcement for RC-walls?

[#3]

Dear Rafal

I would like to thank you for your response  .But, actually  I  calculated the reinforcement for RC-WALLS using this way because I am not able to use RC-WALL module to calculate provided reinforcement since ROBOT always generate edge reinforcement for all cases using ACI318-08M ,but in some cases we don't need this "edge reinforcement )depended on the seismic zone . so, I hope in the next ROBOT version the developers will consider this point .

However ,

If you use the option " Minimum reinforcement  for the whole panel " you will find the Amin = 20 cm2/m . It means that ROBOT use Amin= 0.005x40x100 = 20 cm2/m for vertical reinforcement where wall thickness=40 cm.

But ,since I am designing RC-wall , the minimum reinforcement for vertical side as ACI318-08M ,clause 14.3.2 depended on "Fy ".for my case "Fy= 400 Mpa" then Amin=0.0015bh =0.0015x40x100=6cm2/m. It means not "40 cm2/m or 20 cm2/m"

Then , in my point of view , ROBOT should know firstly the panel is slab or wall because each one of them has a different  "Minimum reinforcement ".

Kindly , correct  me if  my thinking is wrong . I am awaiting your confirmation.

Note : Attached is ACI-code page related to minimum reinforcement for RC-walls?

Thank you for your good cooperation

Refaat

[#4]

It is being checked.

I will update this thread asap.

[#5]

Dear Rafal

Thanks for your interest

Refaat

[#6]

Dear Rafal

You can increase your computer speed by adding SSD (Solid state drives) into your system.with  Raid0 technology.

.

The science behind it ...... Since your model is big and the resulting stifness matrix file will also be big. Creating, writing and reading huge sized matrix files consueme too much time by normal hard disks as they are slow in reading and writing and go max upto 40MB/s .On the other hand SSD without raid0  go upto 400MB/s and with Raid 0 can it shoots upto 800MB/s. This makes a huge difference.

Your life will be easy if you upgrade your machine with a new SSD drive..

Good processor (i7 / Xeon max 3GHz) + SSD + 16 / 32 GB RAM is dream machne for Structural Engineers

Regards

Shafiq ur Rehman

Riyadh, Saudi Arabia