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Admin Comment:
Thank you for your interest in non-linear analysis and patience. All of your questions have been answered and posted on the 'Technical F&Q' pages.
Admin Comment:
You can directly contact
Professor S.L. Chan
Department of Civil & Structural Engineering,
The Hong Kong Polytechnic University,
Hung Hum, Kowloon,
Hong Kong, CHINA
Telephone: (852) 2766-6047
E-mail: ceslchan@polyu.edu.hk
3
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Kelvin
07 July 2010 07:51 | Hong Kong
Dear Sir,
I am a user of NIDA ver.7 and have some queries during using the program.
It is grateful if you can provide us some advice for the following queries.
1) It seem the stress of material is universal for all steel member regardless their thickness. But we actually have to reduce the strength for thicker material. Will Nida automatic reduce the strength? Say 265 for 40mm thick steel section.
2) For Cold Formed CHS, the buckling curve is different from hot finished. If we used second order and equation 8.78, we don't need to use the buckling curve. As such, is there any different in axial force from cold form and hot finished CHS. For my preliminary checking, it seem no difference.
Thanks!
I am a user of NIDA ver.7 and have some queries during using the program.
It is grateful if you can provide us some advice for the following queries.
1) It seem the stress of material is universal for all steel member regardless their thickness. But we actually have to reduce the strength for thicker material. Will Nida automatic reduce the strength? Say 265 for 40mm thick steel section.
2) For Cold Formed CHS, the buckling curve is different from hot finished. If we used second order and equation 8.78, we don't need to use the buckling curve. As such, is there any different in axial force from cold form and hot finished CHS. For my preliminary checking, it seem no difference.
Thanks!
Kelvin
26 March 2010 03:06 | Hong Kong
Dear Sir,
I am a user of NIDA ver.7 and have some queries during using the program.
It is grateful if you can provide us some advice for the following queries.
Q1 Regarding the Analysis Type for “Second-Order Analysis + Beam Buckling” and “Second-Order Analysis + Design” in NIDA ver 7. Do “Second-Order Analysis + Design” included beam buckling analysis as well?
Q2 What is the difference between PEP element and Curved Stability Function? The default value for the program is PEP element, under what circumstance shall we pick Curved Stability Function?
Q3 For Plastic Advanced Analysis, there are two options, one is plastic hinge and one is plastic elements. I assumed it is refer as “plastic hinge model” and “plastic zone model” respectively in structural use of steel 2005. The manual has clear definition on it but the applicability, advantages or disadvantages has not been touch on. Can you give us some advice on these two methods?
Q4 Under what circumstance shall we pick variable load increment for post-buckling analysis?
Q5 For imperfection, the initial imperfection in the analysis is assumed as 0.00x of the member length with reference to BS5950 (where x is the input value and 1 is recommended in the manual.) Do such approach equivalent to the required frame imperfection (H/200) and member imperfection (L/200-500) in Structural Use of Steel 2005?
I am a user of NIDA ver.7 and have some queries during using the program.
It is grateful if you can provide us some advice for the following queries.
Q1 Regarding the Analysis Type for “Second-Order Analysis + Beam Buckling” and “Second-Order Analysis + Design” in NIDA ver 7. Do “Second-Order Analysis + Design” included beam buckling analysis as well?
Q2 What is the difference between PEP element and Curved Stability Function? The default value for the program is PEP element, under what circumstance shall we pick Curved Stability Function?
Q3 For Plastic Advanced Analysis, there are two options, one is plastic hinge and one is plastic elements. I assumed it is refer as “plastic hinge model” and “plastic zone model” respectively in structural use of steel 2005. The manual has clear definition on it but the applicability, advantages or disadvantages has not been touch on. Can you give us some advice on these two methods?
Q4 Under what circumstance shall we pick variable load increment for post-buckling analysis?
Q5 For imperfection, the initial imperfection in the analysis is assumed as 0.00x of the member length with reference to BS5950 (where x is the input value and 1 is recommended in the manual.) Do such approach equivalent to the required frame imperfection (H/200) and member imperfection (L/200-500) in Structural Use of Steel 2005?
Admin Comment:
Thank you for your interest in non-linear analysis and patience. All of your questions have been answered and posted on the 'Technical F&Q' pages.
Devon
07 January 2010 13:44 | Hong Kong
I want to know more about NIDA, how can I contact you.
Thanks.
Thanks.
Admin Comment:
You can directly contact
Professor S.L. Chan
Department of Civil & Structural Engineering,
The Hong Kong Polytechnic University,
Hung Hum, Kowloon,
Hong Kong, CHINA
Telephone: (852) 2766-6047
E-mail: ceslchan@polyu.edu.hk
3
Entrys in the Guestbook
1) It seem the stress of material is universal for all steel member regardless their thickness. But we actually have to reduce the strength for thicker material. Will Nida automatic reduce the strength? Say 265 for 40mm thick steel section.
Reply: NIDA will automatically reduce the strength according to the plate thickness if you select “Linear + Design” or “Second-order + Design”.
2) For Cold Formed CHS, the buckling curve is different from hot finished. If we used second order and equation 8.78, we don't need to use the buckling curve. As such, is there any different in axial force from cold form and hot finished CHS. For my preliminary checking, it seem no difference.
Reply: You are right. The buckling curve of cold-formed CHS is different from that of hot-rolled. Please modify the default value of member imperfection to L/300 (curve “c”) in section properties window after you select “Cold Formed” because NIDA considers the buckling curve in “geometric imperfection” manner but not traditional “strength reduction” manner. This modification may affect the internal forces and moments slightly.