Neither (deflection is neither a derivative of moment nor is moment an
integral of deflection which is saying the same thing) and you left out one
step. Slope is between moment and deflection.
is the integration of shear.
is the integration of moment.
Deflection is the integration of slope.
course, you have to apply boundary and compatibility constraints to arrive at a
|T. William (Bill)
Allen, S.E. (CA #2607)|
|V (949) 248-8588
I’m rusty on
singularity functions. Is it:
load, shear, moment,
deflection. Deflection is
derivative of moment. Or Moment
is integral of deflection. Is
E. Boge, P. Eng.
Boge Boge (1980) Ltd.
268 Ellen Street
Canada, R3A 1A7
p:(204) 942-7276 ext 223
Sent: Wednesday, November 24, 2004 11:43
Re: structures & ethics
In a message dated 11/23/2004
6:29:25 PM Pacific Standard Time, dennis.wish(--nospam--at)verizon.net
I must, with all respect,
disagree with you. Deflection is much more than an
indicator - it is a
function of bending stress and while you should consider
as a means to calculate if creep is the cause of deflection
other issue such as installing crown side down), it does tell me
there is a bending problem or that deflection due to bending exceeds
comes close to exceeding the code allowable limits for deflection of
products. If I recall my calculus (and please - it's been over
- deflection is a derivative of moment or bending, which is
a derivative of
shear. Therefore the relationship of bending to
deflection is a real issue.
Furthermore, in a flat roof or low slope
roof, deflection can lead to
Ponding problems that can exceed allowable
bending due to increased short
Deflection is not necessarily an
indication that bending stress stress has been exceeded and it is not a
function of the bending stress. Eventhough you have excessive deflection
as long as the bending stress and shearing stress are within the allowable
then the structure is still safe. Deflection is only a serviceability
issue. It is not a life treathening issue. Deflection are being
controlled to minimize creeking sounds and bouncy floors on wood
members, unsightful appearance, ponding as you have mentioned, and