Sometimes the software does not realize where columns or rows are supposed to be separated, and I quick-fix that by drawing where I want Excel cell divisions in Bluebeam using the Line or Rectangle tools, flatten the PDF, then export to Excel

LikeLike

]]>LikeLike

]]>it works perfect for a uniaxial eccentricity and converge very fast since you iterate only one variable.

for biaxial eccentricity it seems reasonable to me to rotate the section in an angle equal to ATAN(Mx/My) and calculate the new coordinates (including eccentricity point) by maintaining the N.A horizontal, then solve for also one variable.

a further iteration can be done to iterate the angle of rotation but in most cases it will not be necessary since it’s impact on results is minor in compare to the depth of N.A. and it will not vary much from the first assumed angle.

LikeLike

]]>so the general formula for the strain plane is e = c1x+c2y+c3 with c1,c2,c3 being constants. A base assumption in their calculation is that the base plate and anchors are rotated so that the strain and therefore stress would only vary in the y direction this is done to greatly simplify the double integration needed to get the compression resultant force and associated moments.

the calculation on page 3 utilizes line integrals, Green’s Theorem, to calculate the double integral of the stressed area to get the total force. They also reduced the integration further by doing it parametrically for an arbitrary line with two points and a linear varying stress.

LikeLike

]]>Thanks for sharing, in deed it’s a good reference but i have a “silly” question”, in page 4 it’s mentioned that “The next step is to determine the equivalent forces and moments in the local coordinate system for the concrete compression and anchor rods tension.”

What i understand that i have to rotate the section an assumed angle and solve the equations based on the rotated coordinates, however in page 3 it says that “The equivalent force, moment about local x axis and moment about local y axis for a line segment between node i and node i+1” so it got me confused, do i have to keep rotating the section and solve the equation for each face!!.

unfortunately the numerical example skips the important part which is setting the geometry, i understand that this part specially can be done in many different way’s but still it could had helped allot to show an example.

LikeLike

]]>Don – I couldn’t see anything wrong with the link. I suspect it may be another WordPress “improvement”.

LikeLike

]]>Thanks Doug not sure what I may have done wrong there, will be more careful in future comments.

LikeLike

]]>DonB – I edited your link because it was automatically downloading the pdf and opening it without any prompt. Seems to work OK now.

LikeLike

]]>This PDF from Bentley gives a great break down of the procedure for base plates:

LikeLike

]]>– The N.A. depth

– The N.A. Angel

– The total tension in the bolts

– The maximum stress in concrete

i can’t find any reference to help me to start, i have done it already for uniaxial bending but with biaxial i am stuck!!

any guidance or references will be appreciated.

LikeLike

]]>