MIDAS GEN Steel Designer

Question:

Dear Sir/Madam,

I’m designing a simple supported steel beam and noticed that Midas is not reducing the bending capacity if the shear load is more than 50% of the shear capacity although it does the check for it.

Here is the shear utilization and bending check:



I am using Midas gen 2018 with the latest patch 1.2

Best regards,
 
Answer:
Hello,

Thank you for sending your question.


When performing the design, the program consider the 5 points(i, 1/4, 2/4, 3/4, j) of the member force(is divided into 4 parts) to design the section.

Therefore, to check the shear resistance in the design step, program used V_Edz which is the largest shear force(from j-end) among the 5 points of member (2016kN), and V_Edz/Vpl = 0.631.

But for the design resistance of bending and shear, section is designed for the position which has the largest moment value.
You assigned the elements no.1,2,3 as one member. In the member, and the largest bending moment is occurred at 3/4 points of this member, and in this point the share force was 140kN. Therefore to calculate the V_Edz/ Vpl, program use the 140kN for V_Edz and V_Edz/ Vpl was smaller that 0.5.Because of these reasons, program do not reduce the bending capacity.

However, in the analysis result, you can confirm that the largest bending moment is occured in the i-end of element 3. In this case, it is more exact to design the section without assigning member. To do that, just define the Unbraced Length to the elements with the same value which you defined for the member, and perform the design.
Thank you.

Best regards,
Jihong Hwang
Creation date: 7/25/2018 4:59 AM (dklee@midasit.com)      Updated: 7/25/2018 2:30 PM (dklee@midasit.com)
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Transfer beam L01 Grid FF.acs
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Transfer beam L01 Grid FF.mgb
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