Tag Archives: moment curvature

Non-linear frame analysis; moment curvature and self-weight

The Python/Fortran/Excel frame analysis program (previous version here) now has several new features added to the 2D-solver routines: The beam bending behaviour may now be specified with moment-curvature tables, rather than the linear-plastic behaviour required in the previous version. Beam … Continue reading

Solving non-linear equations with two or more unknowns – 5

This will be the last of the series on solving non-linear equations (for now).  Up until now all the examples have had two unknown values, and two target values.  This can be extended by making three changes to the code: … Continue reading

Solving non-linear equations with two or more unknowns – 4

As promised in the previous post, the spreadsheet including the new functions to calculate reinforced (or prestressed) concrete moment-curvature with a revised concrete tension stress-block is now available for download from: RC design functions7.zip The spreadsheet includes full open source … Continue reading

Solving non-linear equations with two or more unknowns – 3

For the next stage of the non-linear solver saga I am looking at the same problem as in the previous post (finding the curvature or a reinforced concrete section under specified bending moment and axial load), but with more realistic … Continue reading

Posted in Beam Bending, Excel, Maths, Newton, UDFs, VBA | | 1 Comment

Solving non-linear equations with two or more unknowns – 2

The previous post presented a simple but slow procedure for solving non-linear equations with two unknowns.  In this post I will describe a much faster method, that also has the advantage that it can simply be extended to work with … Continue reading

Posted in Beam Bending, Concrete, Excel, Maths, Newton, UDFs, VBA | | 5 Comments

Solving non-linear equations with two or more unknowns – 1

Newton’s Method is a well known iterative solution for non-linear equations with one unknown.  That is, if some value Y depends on a variable X, then we can use Newton’s Method to find X for any given value of Y.  … Continue reading

Posted in Beam Bending, Excel, Maths, Newton, UDFs, VBA | | 2 Comments

Reinforced Concrete Moment Curvature – Development over time

I recently noticed that in the RC Design Functions spreadsheet the TimeCurve function had stopped working.  The function calculates the development of reinforced concrete section curvature over time, and was previously presented in Reinforced Concrete Moment-Curvature – 3; Restrained Shrinkage and Creep and Reinforced … Continue reading