Recent content by elbarto

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    Finding Forces in a tie rod.

    Try making a cut in member (1) and then take the moments about A. You should be able to solve for the axial force directly by using you 3 equations of equilibrium. Elbarto
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    Structural Engineering -12x12 stiffness matrix analysis

    Yes I am doing a full 3D frame element so I have to consider all 12 DOF's for each member. I had a look in my library today and think I managed to find the local member stiffness equations which will probably work ok if I play around with them a bit but I would appreciate it if you could check...
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    Structural Engineering -12x12 stiffness matrix analysis

    Thank you for your reply. That is almost exactly what I am chasing, tho I need the 12x12 stiffness matraix equations because I am considering bending so I will have the 6 additional degree of freedom to account for due to the rotation of each node. If I find the equations I will post them...
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    Hydraulics and the darcy weisbach formula

    I would probably do the same as gmax137 suggested. My step by step approach would be1) Use Bernoulli to get an estimate of Q (ie Q if there was no friction in the system) 2)from the estimate of Q, find your Re and hence get a value for f 3)calculate a new Q and continue to iterate between (2)...
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    Structural Engineering -12x12 stiffness matrix analysis

    Hi, I am trying to write a MATLAB script to do an elastic analysis of 3D frame sturctures. The method I am using is the direct stiffness method, but I cannot find the equations for the 12x12 stiffness matrix for each member in the global system. If anyone has any information on 3D matrix...
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    MATLAB MATLAB Input Function Help | Elbarto

    Hi all, Can someone please help me with my MATLAB code. I am trying to get the program to quite if the user tries to input a non-numeric value, and will display an error message. I have got it to work useing the MATLAB input('promt','s') command, but i don't want to use this command because a...
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    MATLAB Converting Excel Spreadsheet to Matrix and Storing in Mfile

    Hi I have just imported a fairly large matrix from a excel spread sheet (121x6) useing the xlsread function. Is there a way I can convert the matrix from my command window to look something like below. Matrix = [...; ...; ...; ...; ...; ...] I want to know if i can store the matrix in a...
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    MATLAB Frame Solver - MATLAB Program

    Hi, I have been working on a MATLAB program for solving the member forces in a 2d frame structure which many people have helped me out with on this forum. I have finally got the script to a point where it is working ok and have shown the command window output for a solving a simple frame. My...
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    MATLAB Count Rows in Matlab | Elbarto

    Thanks a lot FrogPad, that looks like it will work out well. I will let you know how I get on. Thanks Again Elbarto
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    MATLAB Count Rows in Matlab | Elbarto

    Thanks FrogPad, I will have a play around with those functions and see if I can get them to suit my application. The reason I tried to put all the names ie F1x F1y M1 in a vector is I was intending to use a loop to concatnate the 2 strings as the number of members I solve for changes, so I can't...
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    MATLAB Count Rows in Matlab | Elbarto

    Thanks FrogPad, I appreciate all the help with getting to know these operations in matlab. I hope you don't mind If I ask one more question tho (Il post here so I don't clog the forum up with my amature questions). I get an output like this from MATLAB after I run my program, Rs =...
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    Statics Maximum Weight Problem

    No worries mate, glad I could help you out. Yes in my opinion is the ideal way to show how you concluded that A is 255. The question asks you to find A and theata, so as long as you end up with a solution that at some stage has, Theata=? A=? then as far as I am concerned the question has been...
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    Statics Maximum Weight Problem

    Basically if you have found Fcd to be 1.96 (which is exactly what I got), then for every 1 unit you apply at A, you will expect Fac to increase by 1 unit. Fbc to increase by 1 unit. Fcd to increase by 1.96 units. so what I would do is make the following conclusions, Fcd is the critical...
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    Vector Algebra: Proving Mutually Perpendicular Vectors

    because C is the cross product of A and B, hence it must be perpendicular to both vectors.
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    Statics Maximum Weight Problem

    From what I could tell of your diagram, it looks like BCA is all 1 piece that wraps around the pully and CD is another piece that connects to the middle of the pully. If that is the case, then in you solution you assume that if the load in BC is 500, then the load in CD is 500. If you think...
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