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  


返回   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 » 三维空间:产品设计或CAX软件使用 » CAD设计 » 产品功能分析
用户名
密码
注册 帮助 会员 日历 银行 搜索 今日新帖 标记论坛为已读


 
 
主题工具 搜索本主题 显示模式
旧 2009-09-08, 10:06 PM   #1
huangyhg
超级版主
 
huangyhg的头像
 
注册日期: 04-03
帖子: 18592
精华: 36
现金: 249466 标准币
资产: 1080358888 标准币
huangyhg 向着好的方向发展
默认 elliptical concrete roof

elliptical concrete roof
i am in the process of analysing a curved (elliptical)roof with the following dimensions etc.
span 13'4"
internal dim. -principal axis of ellipse 6'-2" (to centre)
secondary axis of ellipse 3'-11" (from top of roof to centre)
thickness 6",
reinforcement 3/8"h.t. bars longt. @10" c.c longt., top and bot. bars aligned radially /3/8" h.t. bars (curved) @10" c.c ( all top and bottom)
please verify if these dimensions and reinf. are adequate or advise on how i should approach the design.
regards,
jdw

i can't visualize the shape from your description.
span 13'4" - are you talking about a dome shape with an oval base?
engcomp,
thanks for responding.
not exactly, the shape is similar to a cylindrical shell roof. however, instead of being an arc of a circle as in the cylindrical shell roof, the curve forming the roof is half of an ellipse. the building is 43' long and 13'4" wide.
jdw
and the "shell" is supported along the 43' length?
hi, jdw
with continuous support along the length of the "shell", what we have is actually an elliptic arch. the thrust line is a shape governed by the selfweight and superimposed loads, for example a parabola if the loads were uniformly distributed. you will note that the shape corresponds to the bending moment line of a freely supported
hi, janine
thanks for your email. the answer should go here because it might benefit others.
the thrust line is any line you can draw that links all given loads (i presume you know how to draw force diagrams). you will note that it requires a horizontal component to draw the line. that component must be supplied by the arch's supports. if the supports cannot supply the horizontal component, then the optimum thrust line cannot be achieved.
for example, if one support is freely sliding, the moments in the arch are the same as in a straight, freely supported member. the only difference is that the self weight is different from a straight member.
check your 6" section for that first. if it's ok, don't worry about arch action.
regards, helmut
__________________
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]
huangyhg离线中   回复时引用此帖
GDT自动化论坛(仅游客可见)
 


主题工具 搜索本主题
搜索本主题:

高级搜索
显示模式

发帖规则
不可以发表新主题
不可以回复主题
不可以上传附件
不可以编辑您的帖子

vB 代码开启
[IMG]代码开启
HTML代码关闭

相似的主题
主题 主题发起者 论坛 回复 最后发表
concrete sampling guidlines huangyhg 产品功能分析 0 2009-09-08 12:34 PM
concrete roof slab load huangyhg 产品功能分析 0 2009-09-08 12:34 PM
concrete mix= reinfocing for exterior composit deck huangyhg 产品功能分析 0 2009-09-08 12:19 PM
concrete corrosion in partial saturated condition huangyhg 产品功能分析 0 2009-09-08 11:54 AM
chapter 4 preliminary design properties of concrete huangyhg 产品功能分析 0 2009-09-07 11:23 PM


所有的时间均为北京时间。 现在的时间是 05:05 AM.


于2004年创办,几何尺寸与公差论坛"致力于产品几何量公差标准GD&T | GPS研究/CAD设计/CAM加工/CMM测量"。免责声明:论坛严禁发布色情反动言论及有关违反国家法律法规内容!情节严重者提供其IP,并配合相关部门进行严厉查处,若內容有涉及侵权,请立即联系我们QQ:44671734。注:此论坛须管理员验证方可发帖。
沪ICP备06057009号-2
更多