International Skeptics Forum - View Single Post - A Question for Heiwa

Heiwa · 15th March 2009, 01:51 PM

Originally Posted by moorea34

Dear Heiwa,

Why have you changed this text TODAY in your site

Remember that the outer core columns are extremely solid, e.g. no. 501. It is an H-beam with two flanges 17x3.5 inch connected by a 2.2x12.6 inch web. In metric terms the flanges are 430x90 mm and the web is 56x320 mm. Such thick plates, 56 and 90 mm cannot buckle under any circumstance when the compressive stress is only 30% of yield stress, even if the temperature is 500°C. The (smallest) moment of inertia I of this section is about 120 000 cm4 and its radius of gyration r is thus of the order 35 cms. With a free length l of 350 cms the slenderness ratio (l/r) is 10! Removing three floors as support and the free length is 1 400 cms and the slenderness ratio is still only 40! Such a column will not buckle!

by this one

§7.2 of page ...nist1.htm

Remember that the outer core columns are extremely solid, e.g. no. 501. It is an H-beam with two flanges 17x3.5 inch connected by a 2.2x12.6 inch web. In metric terms the flanges are 430x90 mm and the web is 56x320 mm. Such thick plates, 56 and 90 mm cannot buckle under any circumstance when the compressive stress is only 30% of yield stress, even if the temperature is 500°C. The (smallest) moment of inertia I of this section is about 120 000 cm4 and its radius of gyration r is thus of the order 11 cms. With a free length l of 350 cms the slenderness ratio (l/r) is 32! Such a column will not buckle! Same for the wall columns that have a radius of gyration r of abt 15 cms and a slenderness ratio of 24, when supported by spandrels and floors. We know how the core columns were joined and that it seems most failed at their weld planes, with little to no buckling involved.

???

Because I have written TODAY in my site that you don't know how is calculated the radius of gyration ??

What site do you have? I have never visited it and I haven't got a clue who you are! But you are right - I corrected a typo in my article today. Doesn't change the conclusions, though: the main observation/conclusion in my paper is that a small upper part C of a structure of many elements cannot crush the lower part A of the structure due to gravity alone and some local failures and nobody seems to be able to debunk that! FoS of local steel elements do not really matter.

Try to debunk that! Try to build a structure with two parts C and A of similar structure that collapses when C drops on A!

15th March 2009, 01:51 PM	#91
Heiwa Banned Join Date: Jul 2007 Posts: 3,148	Originally Posted by moorea34 Dear Heiwa, Why have you changed this text TODAY in your site Remember that the outer core columns are extremely solid, e.g. no. 501. It is an H-beam with two flanges 17x3.5 inch connected by a 2.2x12.6 inch web. In metric terms the flanges are 430x90 mm and the web is 56x320 mm. Such thick plates, 56 and 90 mm cannot buckle under any circumstance when the compressive stress is only 30% of yield stress, even if the temperature is 500°C. The (smallest) moment of inertia I of this section is about 120 000 cm4 and its radius of gyration r is thus of the order 35 cms. With a free length l of 350 cms the slenderness ratio (l/r) is 10! Removing three floors as support and the free length is 1 400 cms and the slenderness ratio is still only 40! Such a column will not buckle! by this one §7.2 of page ...nist1.htm Remember that the outer core columns are extremely solid, e.g. no. 501. It is an H-beam with two flanges 17x3.5 inch connected by a 2.2x12.6 inch web. In metric terms the flanges are 430x90 mm and the web is 56x320 mm. Such thick plates, 56 and 90 mm cannot buckle under any circumstance when the compressive stress is only 30% of yield stress, even if the temperature is 500°C. The (smallest) moment of inertia I of this section is about 120 000 cm4 and its radius of gyration r is thus of the order 11 cms. With a free length l of 350 cms the slenderness ratio (l/r) is 32! Such a column will not buckle! Same for the wall columns that have a radius of gyration r of abt 15 cms and a slenderness ratio of 24, when supported by spandrels and floors. We know how the core columns were joined and that it seems most failed at their weld planes, with little to no buckling involved. ??? Because I have written TODAY in my site that you don't know how is calculated the radius of gyration ?? What site do you have? I have never visited it and I haven't got a clue who you are! But you are right - I corrected a typo in my article today. Doesn't change the conclusions, though: the main observation/conclusion in my paper is that a small upper part C of a structure of many elements cannot crush the lower part A of the structure due to gravity alone and some local failures and nobody seems to be able to debunk that! FoS of local steel elements do not really matter. Try to debunk that! Try to build a structure with two parts C and A of similar structure that collapses when C drops on A!
Heiwa Banned Join Date: Jul 2007 Posts: 3,148	Last edited by Heiwa; 15th March 2009 at 02:22 PM.