几何尺寸与公差论坛------致力于产品几何量公差标准GD&T (GDT:ASME)|New GPS(ISO)研究/CAD设计/CAM加工/CMM测量 - 查看单个帖子

the cost of drift
it amazes me every time i size my structure for gravity loads and then go back to do the lateral analysis at how much larger my members need to be due to drift limitations. for instance, in my current project (one-story retail type steel building) it has doubled the size (by weight) of my members. wind usually controls in my part of the country and i have read the many posts that have discussed the topic of the allowable amount of drift for serviceability. i am using the 10-year wind pressure as recommended by aisc design guide 3. i am interested in some feedback on what process other engineers use for optimizing a moment frame to reduce drift. do you have any rules-of-thumb that may apply to proportioning the column size to beam size for maximized stiffness?
find a job or post a job opening
are you using the 0.7 factor on wind loads per ibc?
regardless of any drift limitations, i limit the lateral movement to 1/2" in any moment frame in any single story window wall application. no exceptions.
mike mccann
mmc engineering
i am using the .7 factor but it has been my interpretation that is (.7)(50-year wind event). according to aisc design guide 3, that is approximately the same thing as the 10-year event.

2009-09-16, 01:32 PM	#1
huangyhg 超级版主注册日期: 04-03 帖子: 18592 精华: 36 现金: 249466 标准币资产: 1080358888 标准币	he cost of drif the cost of drift it amazes me every time i size my structure for gravity loads and then go back to do the lateral analysis at how much larger my members need to be due to drift limitations. for instance, in my current project (one-story retail type steel building) it has doubled the size (by weight) of my members. wind usually controls in my part of the country and i have read the many posts that have discussed the topic of the allowable amount of drift for serviceability. i am using the 10-year wind pressure as recommended by aisc design guide 3. i am interested in some feedback on what process other engineers use for optimizing a moment frame to reduce drift. do you have any rules-of-thumb that may apply to proportioning the column size to beam size for maximized stiffness? find a job or post a job opening are you using the 0.7 factor on wind loads per ibc? regardless of any drift limitations, i limit the lateral movement to 1/2" in any moment frame in any single story window wall application. no exceptions. mike mccann mmc engineering i am using the .7 factor but it has been my interpretation that is (.7)(50-year wind event). according to aisc design guide 3, that is approximately the same thing as the 10-year event. __________________ 借用达朗贝尔的名言：前进吧，你会得到信心! [url="http://www.dimcax.com"]几何尺寸与公差标准[/url]