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  1. M

    Concrete bridge pier formwork design

    For the setting part, there is usually a limit of how high the concrete can be poured at any one time. The hydrostatic pressure can be calculated based on this height. If the concrete is in fact poured continuously to the top, some sort of estimate of the concrete setting can be applied, but...
  2. M

    Concrete bridge pier formwork design

    As a first approximation, you would consider fresh concrete as a viscous fluid with a density 2.5 times that of water. So hydrostatic pressure (increases with depth) is a primary consideration. The spacing of fasteners of the two halves has to be looked at, as well as local deformation. Since...
  3. M

    Trussel buckling,question from mechanics of materials

    As a starter, I suggest you analyze the structure to find, step 1: for each member of the truss, calculate maximum force without buckling - magnitude of the force - magnitude of the stress - direction of the force (compression or tension) - the maximum value of F that will keep the...
  4. M

    Fixed-point iteration method to find an approximation

    There is no iteration in x=(25)^(1/3) so the calculator simply evaluated the expression and gave the answer. x needs to be on the right hand side to initiate iterations (e.g. x0=2) if x=5/sqrt(5) does not satisfy the [2,3] interval conditions, you'll need to find other functions such as...
  5. M

    Fixed-point iteration method to find an approximation

    OK, use Xn+1=5/sqrt(Xn), but you can use a=2.8, a^3=21.952 b=3, b^3=27 then 5/sqrt(a)=2.988<3 and 5/sqrt(b)=2.886...>2.8
  6. M

    Fixed-point iteration method to find an approximation

    Newton's works very well when we put f(x)=x^3-25 It converges to 2.924017738212866 in 7 iterations starting with x0=2, and in 5 starting with x0=3.
  7. M

    Fixed-point iteration method to find an approximation

    Can you describe what is a "fixed point iteration" as you understand it? I see it as an iterative function F(x) such that Xn+1 = F(Xn) similar to Newton's method which eventually gives a value very close to the required solution. See also: http://en.wikipedia.org/wiki/Fixed_point_iteration
  8. M

    What is the formula for bending moment of a beam subjected to UDL and a point load?

    As per my previous response: "A centrally loaded column not subject to lateral loads does not incur first order bending moments. Second and higher order bending moments could be caused by lateral buckling or deflections (P-delta effects)." Is the column monolithic with other structures...
  9. M

    What is the formula for bending moment of a beam subjected to UDL and a point load?

    Maximum positive bending moment at the centre of wL^2/24 is correct for a fixed-fixed beam. If you are doing the design of a beam, do not forget that the negative support moments of wL^2/12 are higher than that at the centre. Draw the bending moment diagram would make it clear.
  10. M

    What is the formula for bending moment of a beam subjected to UDL and a point load?

    rock.freak667 will have to interpret the application of his formula. wL^2/8 is the maximum BM at the centre of a udl of w kg/m for a simply supported beam. In fact, all these questions about formulas can be resolved by standard tables available in books or the web, such as...
  11. M

    What is the formula for bending moment of a beam subjected to UDL and a point load?

    For a horizontal simply supported beam of length L subject to udl w, the maximum bending moment is at the centre and equal to wL^2/8 distributed along the span parabolically. For a horizontal simply supported beam of length L, and subject to a point load P at mid-span, the maximum bending...
  12. M

    Fortran Fortran Forum

    It depends how your data are arranged. If the data files are named in a systematic way, it is easy to process them one by one. See post#124 of this thread (on page 8) for an example. If your data file is generated on the fly in Unix, and you have a script to run the fortran program immediately...
  13. M

    Project Euler problem 3

    for(BigInt y = x/2; y>2; --y) Just a suggestion: since the largest prime factor of x cannot not exceed x0=(int)sqrt(x), it pays to start at x0, especially for large numbers.
  14. M

    Fortran Fortran Forum

    For Lanz, try the following link: http://www.cse.yorku.ca/~roumani/fortran/ftn.htm and see if you could find anything here: http://www.thefreecountry.com/compilers/fortran.shtml For Anglea, Since you are looking for the detailed usage of a Unix command "find -name....", you may want to make a...
  15. M

    Fortran Fortran77: Data I/O in big file

    It depends on how you use the file. If it is a huge stiffness matrix which you have to read from A-Z, then you do not have too many options. If it is a file from which you extract information ("I only need a few data points during the calculations"), then you may seriously consider using the...
  16. M

    C/++/# In line vs. In function produces different results in C++

    Could it also be that when the code is plugged in the main, many temporary variables cannot be released, while when tucked into a method, garbage collection is sure to get rid of the unused local variables, and probably faster?
  17. M

    Fortran Fortran Forum

    Some compilers have profilers built-in for this purpose. Most profilers can decompose the running time spent in different programming units. Profilers are compiler dependent and most probably operating system dependent, and are not part of the Fortran language. If you run on Unix, you can...
  18. M

    Fortran Fortran Forum

    This snippet should help you. If your suffixes are letters, you only need to create an array of suffixes to append to the base name. If it is numeric, convert it to a character as shown in the snippet. character*12 filename character*1 num do 20 I=1,9...
  19. M

    Unicode (UTF-8) for overlined characters

    In fact, the tex code is very useful for me too, as I need to write that as one of my steps! Thank you both of you for the prompt response.
  20. M

    Unicode (UTF-8) for overlined characters

    Hello, I have been trying to find the unicode (UTF-8) character codes for overlined upper case letters (V,L,C,M) for use in Roman numerals with the 1000-multiplier. It is basically the same letter with a bar on top of the letter. I also need the overlined decimal digits to display recurring...
  21. M

    Very stuck on loads on a beam

    should probably read I do not know what textbooks you use for the course, but Chapter IV of the classic book derives all the required equations above from first principles and has worked examples very similar to the simple case you mentioned. The reference should be easily available from...
  22. M

    Help! can not compile package with f77

    The start-up file may not be called profile.sh, depending on the kernel you are using (bash?). It may also reside in /etc. The path would have been added on by the installation program. Looking back at your information, I find that the file is here: /opt/intel/Compiler/11.0/083/bin/ia32/ifort...
  23. M

    Fortran Fortran Forum

    If there are no libraries available for this purpose, you will have to write your own. If the polygon is convex, I would subdivide the polygon into triangles and write a double integration function for a triangle with the given vertices, together the given weight function. For integration...
  24. M

    Help! can not compile package with f77

    In: PATH="/opt/intel/Compiler/11.0/083/bi/ia32n:$PATH" export PATH According to the locate command's output, shouldn't it be: PATH="/opt/intel/Compiler/11.0/083/bin/ia32n:$PATH" export PATH Also, you may have an error in the startup file, probably called profile.sh in your main user directory...
  25. M

    Fortran Fortran Forum

    Are you looking for simply the area, or do you put weights throughout the area? If it is a matter of simply the area, you do not need to integrate. There are formulae for calculating the area of a non-self intersecting polygon from the known vertices. See for example...
  26. M

    Fortran Fortran Forum

    Try 999 FORMAT(2x,I2,5x,F9.6,5x,F9.6,5x,F9.6,5x,F9.6,5x, F9.6 / F9.6,5x, F9.6) or 999 FORMAT(I4,F14.6,F14.6,F14.6,F14.6,F14.6 /F18.6,F14.6)
  27. M

    Fortran Fortran Forum

    I do not think one implies the other. Try a 30-60-90 triangle. The side lengths are 1,2 and sqrt(3), the last side being irrational. Yet the angles are rational fractions (1/6, 1/3, 1/2) of π. The converse is not valid either. For example, a triangle with rational sides such as 1,2,3 will have...
  28. M

    Fortran Fortran Forum

    The last number (4.47213595) appears to be 2sqrt(5), while the other ones (2.82842712) appear to be 2sqrt(2).
  29. M

    Fortran Fortran Forum

    It doesn't look like rational to me. It is almost impossible to know from a single number because of rounding errors. Would you have an idea of the three sides?
  30. M

    Fortran Fortran read

    It may be that gfortran defaults to utf-8 which is not compatible with the native code for ubuntu. You may want to do some tests with text files created in ubuntu using native editors such as EMACS or vi. But I'm glad it all works out.
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