# What is Columns: Definition and 105 Discussions

A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member. The term column applies especially to a large round support (the shaft of the column) with a capital and a base or pedestal, which is made of stone, or appearing to be so. A small wooden or metal support is typically called a post, and supports with a rectangular or other non-round section are usually called piers.
For the purpose of wind or earthquake engineering, columns may be designed to resist lateral forces. Other compression members are often termed "columns" because of the similar stress conditions. Columns are frequently used to support beams or arches on which the upper parts of walls or ceilings rest. In architecture, "column" refers to such a structural element that also has certain proportional and decorative features. A column might also be a decorative element not needed for structural purposes; many columns are engaged, that is to say form part of a wall. A long sequence of columns joined by an entablature is known as a colonnade.

View More On Wikipedia.org
1. ### Engineering Statics: Point loads on columns

If it was about beams, I would usually do clockwise and anti-clockwise first, taking moments on A/B, clockwise forces times distance = anti-clockwise forces times distance, since its in equilibrium.
2. ### MHB How can I get equal columns and rows from a total?

I have a number of cells (say 10 cells) but that number is a variable. I have the value of the variable but it's not a 'hard' number. We'll call the variable x. I need to calculate how many columns I'll have if the columns and rows will be the same, or the columns will be 1 minus (floor) the...
3. ### Imperfection moment of columns

Homework Statement:: Anyone familiar with prokon column design ? I have no idea how the program caluculate the imperfection moment in the slender column (braced/unbraced... Relevant Equations:: I have attached an example here , it's an unbraced slender column here. Why the imperfection moment...
4. ### I'm trying to understand compressive strength and Euler stress for columns

A cloumn has a compressive strength of 220MPa, but its Euler yeild stress is 350MPa. its compressive strength is less than its euler stress. what does this mean?
5. M

### MATLAB Calculating Mean of Columns with NaN Values in Matrix A

Hi PF! Given a matrix A = [1 2; nan 3; 3 4], how can I calculate the mean so that the resulting matrix averages the columns but ignores the nan values as non-entries, so that the mean of matrix A outputs [2,3]? Thanks so much!

17. ### I Matrix of columns of polynomials coefficients invertibility

I am reviewing the method of partial fraction decomposition, and I get to the point that I have a matrix equation that relates the coefficients of the the original numerator to the coefficients of the numerators of the partial fractions, with the each column corresponding to a certain polynomial...
18. ### MATLAB How can I append new columns to an existing Excel file with MATLAB?

I would like to ask how to use MATLAB to append new columns into existing excel file without altering the original data in the file? In my case I don't know the original number of columns and rows in the file and it is inefficient to open the files one by one and check in practice. Another...
19. ### Merging columns from two text files

Suppose I have two .txt files: >>text1.txt X Y Z x1 y1 z1 x2 y2 z2 ... xN yN zN >>text2.txt W R w1 r1 w2 r2 ... wN rN Is it possible to merge the collumns in a single txt file like: >>merged.txt X Y Z W R x1 y1 z1 w1 r1 x2 y2 z2 w2 r2...
20. ### Catenary lighting canopy -- Working out reactions at columns

Hi guys, first time poster so play nice :) Outline of problem: The situation I have is that there are 4 supporting columns. These columns support support a wire and this wire is then used to hang wires which support festive lights. (see diagram below) What I'm looking for as an end point is...
21. ### Determine Floor Load on Columns: Hi Everyone!

Hi everyone.I would really appreciate if someone would help me with determination of floor load on columns (column tributary area). Normally uniformly distributed load acting on a beam is halved and each half-load is allocated to one column supporting the beam. In this case however, there is...
22. ### Renaming Columns in DB Table: Apex SQL or Examine Dependenci

Hi All, Just curious as to what those with experience in creating databases believe is the best method when renaming databases: using Apex SQL , which (supposedly) automatically checks for dependencies or just sitting down , looking at the dependencies and doing the changes one by one as needed...
23. ### Mathematica Is it possible to colour the rows or columns of a matrix?

Hi, I was wondering if it's possible to colour the rows and columns of a matrix in mathematica. I have received help from another forum and the code of my matrix is the following: Rasterize@ Style[MatrixForm[{{n, -1 + n, -2 + n, \[CenterEllipsis], 1}, {2 n, 2 n - 1, 2 n - 2...
24. ### Finding pressure P of air held in between two columns of Mercury

Homework Statement Homework Equations P=hρg The Attempt at a Solution The length of mercury column ... (1) on the left side (exposed to atmosphere) would be ( 760 + x/2 )mm (2) on the right side (exposed to atmosphere) would be ( 760 + (50-y)/2 )mm (3) on the left (exposed to air at...
25. ### Fill in the empty columns of a work/power table

Homework Statement "Fill in the empty columns of the following table" Table is in the thumbnail Homework Equations work = force / distance power = work / time Y = E * c -Y is the yearly running cost -E is the EnerGuide energy rating per year -c is the cost of electricity per kW/h The...
26. ### Expressing non-basis columns as a linear combination

Homework Statement A= \begin{bmatrix} 1 & 1 & 1 & 2 & 5 \\ 2 & 3 & 1 & -1 & -5 \\ 1 & 0 & 2 & 0 & -1 \\ 1 & 2 & 0 & 1 & 2 \end{bmatrix} Homework Equations I get this RREF \begin{bmatrix} 1 & 0 & 2 & 0 & 0 \\ 0 & 1 & -1 & 0 & 0 \\ 0 & 0 & 0 & 1 & 3 \\ 0 & 0 & 0 & 0 & 0...
27. ### Proving dependent columns when the rows are dependent

I feel like I almost understand the solution I've come up with, but a step in the logic is missing. I'll post the question and my solution in LaTeX form. Paraphrasing of text question below in LaTeX. Text question can be seen in its entirety via this imgur link: http://i.imgur.com/41fvDRN.jpg...
28. ### Friction Factor for Wetted Wall Columns

Hi! I encountered this problem that asked for the friction factor of a very dilute SO2-air gas mixture in a wetted wall column. All the necessary information were given to compute for the Reynold's number. What I want to know is does having a wetted wall make it a different case (ergo use...
29. ### Slab on a Brick wall (Only 3 columns)

I have a 3 story building. Will it be possible to put a slab (to make it a roof top) on a brick wall at 2nd floor? It was designed to construct a roof. Dimensions of brick wall: 8' X 14' Or please suggest me the best way to make a roof top on it.
30. ### Concrete Columns: Building a 3-Floor House

This is regarding a building a house with 3 floors. I have seen some masons are first do the concrete structure and then they do the brick structure. But I have seen some do the basement first and do the bricks first and in between they keep a space for columns and they pour concrete mixture in...
31. ### Open-Ended Air Columns: Natural Freq of Cylinder?

When we calculate the natural frequency of an open-ended air column, is the natural frequency we calculated pertaining to the air column or the hollowed cylinder containing the air column? I imagine that the natural frequency belongs to the hollowed cylinder, for the natural frequency of...
32. ### Matrices: Rows and Columns Meaning

I'm trying to learn column space currently and I'm confused about the meaning of rows and columns. So I'm given this definition for column space: "The column space of matrix A is the set Col A of all linear combinations of the columns of A" Given the matrix A: [ 1 -3 -4 ] [ -4 6 -2 ] [ -3 7...
33. ### Proving that Columns are Linearly Dependent

Homework Statement Let A be an m x n matrix with m<n. Prove that the columns of A are linearly dependent. Homework Equations Its obvious that for the columns to be linearly dependent they must form a determinate that is equal to 0, or if one of the column vectors can be represented by a...
34. ### Hydrogen bonding force problem

Homework Statement In a DNA molecule, the base pair adenine and thymine is held together by two hydrogen bonds (see figure below). Let's model one of these hydrogen bonds as four point charges arranged along a straight line. Using the information in the figure below, calculate the...
35. ### Proof that det(M)=0 => Linear Dependence of Columns

Homework Statement Prove that for a general NXN matrix, M, det(M)=0 => Linear Dependence of Columns Homework EquationsThe Attempt at a Solution It's not clear to me at all how to approach this. We've just started Linear algebra and this was stated without proof in lecture. I have no idea how...
36. ### Fortran Exploring Unimplemented Data Structures in C: Matrix Storage by Columns

See attached image. I have never heard that before. Why wouldn't one be able to implement a data structure that stores a matrix by its columns using C? Is that true?
37. ### Multiplication of an Identity Matrix by a Column

Homework Statement [/B] This is a seemingly simple problem. All I have to do is multiply two matrices: [ 1 0 ] [ 0 1 ] (A) and [ 2 ] [ 3 ] (B) The Attempt at a Solution [/B] Because the matrix A has the same number of columns as matrix B has rows, and because matrix A is an identity matrix...
38. ### How to Express the Curve of a String Hung Between Two Columns

1. Imagine two columns between which is hung a string. The hung string may be expressed graphically and mathematically as a parabola whose nature is exponential. If these columns are moved closer together or farther apart, the hung string becomes more loose or taut according to a trigonometric...
39. ### How to Calculate Safety Factor for Beam Columns?

Beam held up by two columns I apologize in advance if you think this should really go in the homework help area, I am not sure because this isn't a homework problem, but rather my struggle to understand and carry out concepts. If it needs to be re-posted, or moved, I understand. :) In a...
40. ### Is it Necessary to Keep Zero Columns in an Augmented Matrix?

If you have an augmented matrix and one column in your matrix is all zero (but not the answer column) are you able to 'delete' the all zero column and the corresponding variable? Because when you write out the equations, the co-efficient's of the variable corresponding to the all zero column are...
41. ### Problem With Columns: Finding Load for Buckling

Hi every body this is my first post on these forums. I have a hollow column made from structural steel that has a Young's modulus of 200GN m^-2 and a yield stress of 140MN m^-2 it is 10m long. the larger radius R is 40mm the smaller r is 30mm I am asked to find the load that will cause it to...
42. ### Mathematics of circular shifts of rows and columns of a matrix

What mathematical algebra explains sequence of circular shifts on rows and columns of a matrix? Consider a simple matrix (3X3) with entries thus: [1 2 3; 4 5 6; 7 8 9;] Circular shifts can be performed on any row or any column thus: row-(1/2/3)-(right/left) and column-(1/2/3)-(up/dn)...
43. ### Free columns-combinations of columns?

In Gilbert Strang's book on linear algebra, he mentions that pivot columns are not combinations of earlier columns and that free columns are combinations of earlier columns. What columns is he referring to by earlier columns? Also, what property distinguishes pivot variables and free...
44. ### Determinant of a unit columns matrix

If all columns of a matrix are unit vectors, the determinant of the matrix is less or equal 1 I am trying to prove this assertion,which i guess to be true. can anybody help me? Thank's in advance
45. ### Invertible matrix implies linear independent columns

Is the title statement true? Was doing some studying today and this caught my eye, haven't looked into linear algebra in quite a while so I'm not sure how it is true :/ Internet couldn't provide any decisive conclusions neither Many thanks
46. ### Optimizing Temp. Tappings on Distillation Columns - Ideas/Experience?

We have a distillation column with insufficient temperature tappings. In order to do a rough survey of the temperature profile externally an idea is to drill small (say 1 inch) holes in the insulation and take external temperature readings. Would a IR temp. gun like this one be a good idea...
47. ### MATLAB, single command for multiple columns

Homework Statement Create the following matrix by typing one command. Do not type individual elements explicitly. \begin{array}{ccc} 0 & 0 & 0 & 0 & 0 \\ 0 & 0 & 1 & 4 & 7 \\ 0 & 0 & 2 & 5 & 8 \\ 0 & 0 & 3 & 6 & 9 \\ \end{array} Homework Equations None The Attempt at a...
48. ### Rank of a Matrix and whether the columns span R12

Homework Statement Let M be the 12 x 7 coefficient matrix of a homogeneous linear system, and suppose that this system has the unique solution 0 = (0, ..., 0) \in ℝ7. 1. What is the rank of M. 2. Do the columns of M, considered as vectors in ℝ12, span ℝ12. Homework Equations The...
49. ### Solution x spanning columns of A

This is a really odd question to me. Usually we talk about b (in Ax=b) spanning the columns of A but here its talking about x spanning A. If x=<-3,4,8> (this is a vertical 3x1 matrix) is a solution to Ax=0, then is x in the set spanned by the columns of A? I'm pretty sure it is no, but i...
50. ### Why is it not possible for the columns of a matrix to span R^2 even if

Why is it not possible for the columns of a matrix to span R^2 even if those columns do not span R^3?